WO2022061941A1

WO2022061941A1 - Battery parameter measurement method and apparatus

Info

Publication number: WO2022061941A1
Application number: PCT/CN2020/118595
Authority: WO
Inventors: 范团宝; 蒋越星; 贺晓虎; 戚文
Original assignee: 华为技术有限公司
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2022-03-31
Also published as: CN114585935A

Abstract

The present application relates to the field of battery testing. Disclosed are a battery parameter measurement method and apparatus. The battery parameter measurement method comprises: measuring the current and the voltage of a battery at a first moment, the first moment being a moment when the battery is charged; stopping charging the battery; measuring the voltage of the battery respectively at 2n moments after the first moment, wherein the interval between the first moment and any two adjacent moments in the 2n moments is a first duration, and n is an integer greater than or equal to 1; and determining battery parameters of the battery according to the current and the voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration. By means of the method, measurement conditions for the battery parameters can be reduced, and the battery parameters are measured in the battery charging process, so that the battery parameters of the battery can be obtained in real time, so as to detect possible abnormalities of the battery in time.

Description

Battery parameter detection method and device

technical field

The embodiments of the present application relate to the field of battery detection, and in particular, to a battery parameter detection method and device.

Background technique

With the rapid development of fast charging technology, battery safety is particularly important. In order to accurately judge the health status of the battery, it is necessary to detect the battery parameters in real time. According to the detected battery parameters, the abnormal condition of the battery can be found in time to prevent the occurrence of safety accidents. For example, common battery parameters include: alternate current resistance (ACR), direct current resistance (DCR), electrochemical impedance spectroscopy (EIS), and polarization time constant. Among them, ACR can reflect whether the battery has an abnormal internal short circuit; 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 of the battery, the degree of aging, and the power supply capability of the battery under specific conditions (eg, low temperature conditions).

At present, when detecting the above-mentioned battery parameters such as ACR, DCR, EIS, polarization time constant, etc., it is generally necessary for the system (that is, the circuit system where the battery is located, hereinafter referred to as the system) to load a periodic square wave or sine wave current to the battery. Or pull a constant current. Taking the detection of ACR as an example, the system needs to load a square wave or sine wave current I(n) of 1 kilohertz (kHz) to the battery through a current source, and at the same time sample the voltage change value V(n) at both ends of the battery, and measure the voltage change value. After the Fourier transform of V(n) and current I(n), the impedance information of the battery under 1k can be obtained by dividing the fundamental frequency information. The real part of the impedance information is the ACR value of the battery.

However, in the process of using the battery, the system (such as the circuit system where the battery is located) has no rules for the current drawn by the battery, and it is difficult to realize the periodic square wave or sine wave current, constant current current, etc. The detection of battery parameters such as ACR, DCR, EIS, polarization time constant, etc., generally needs to be performed under the condition that the battery charger is in place but not charging (that is, the battery is fully charged at this time), and cannot be charged while the battery is being charged. In the process, the detection of battery parameters is realized.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a battery parameter detection method and device, which can detect battery parameters during battery charging.

In a first aspect, an embodiment of the present application provides a battery parameter detection method, including: at a first moment, detecting the current and voltage of the battery, where the first moment is the moment when charging the battery; stopping charging the battery; The voltage of the battery is detected at 2n moments after the moment; among them, the first moment and any two adjacent moments in the 2n moments are separated by the first time length, and n is an integer greater than or equal to 1; according to the voltage of the battery at the first moment The current and voltage, the voltage of the battery at 2n times, and the first duration determine battery parameters of the battery.

Optionally, the battery parameters of the battery include at least one of the following: alternating current resistance ACR, direct current resistance DCR, electrochemical impedance spectroscopy EIS, and polarization time constant.

Through this method, the detection conditions of battery parameters can be reduced, and the battery parameters can be detected during the charging process of the battery, so that the battery parameters of the battery can be obtained in real time, and the possible abnormality of the battery can be detected in time, thereby reducing the damage caused by improper use of the battery. The resulting lifespan decay and even safety accidents will bring users a better experience.

In a possible design, determining the battery parameters of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n moments, and the first duration, includes: according to the current of the battery at the first moment Sum voltage, the voltage of the battery at 2n times, and the first duration, determine the parameters of the battery's n-order impedance equivalent circuit model; determine the battery parameters of the battery according to the parameters of the battery's n-order impedance equivalent circuit model.

In a possible design, according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n times, and the first duration, the parameters of the n-order impedance equivalent circuit model of the battery are determined, including: according to The current and voltage of the battery at the first moment, and the voltage of the battery at the first moment in the 2n moments, determine the parameter R0 of the n-order impedance equivalent circuit model of the battery;

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 system.

Wherein, Vbat(0) represents the voltage of the battery at the first moment; Vbat(1) to Vbat(2n) represent the voltage of the battery at 2n moments respectively; I represents the current of the battery at the first moment; t represents the first duration; e is a natural constant.

For example, the n-order impedance equivalent circuit model of the battery may be a second-order impedance equivalent circuit model, a first-order impedance equivalent circuit model, or the like. The parameters of the second-order impedance equivalent circuit model include: parameter R0, parameters (Re, τe), (Rp, τp). The parameters of the first-order impedance equivalent circuit model include: parameter R0, parameter (Re, τe).

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. parameters, and calculate the ACR, DCR, EIS, polarization time constant, etc., which can effectively reduce the development cost.

In a possible design, determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery includes: determining the ACR of the battery according to the following equation.

In a possible design, determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery includes: determining the DCR of the battery according to the following equation.

Among them, ΔT represents a fixed discharge time and is a constant. For example: ΔT is 1 second, 3 seconds, etc.

In the current DCR detection, pulling a constant current for a period of time (eg, ΔT) increases power consumption, but the embodiment of the present application does not need to pull a constant current, which relatively reduces power consumption.

In a possible design, determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery includes: determining the EIS of the battery according to the following equation.

Wherein, f represents the 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.

The current EIS needs to be measured once per frequency, and the overall test time is long (for example, it takes about 2 minutes to measure from 1000Hz to 1Hz), and the user experience is poor. The current data can be calculated in combination with the algorithm to obtain the EIS of the battery, which can effectively improve the user experience.

In a possible design, determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery includes: determining that the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery are the poles of the battery. time constant.

The current battery polarization time constant calculation adopts the least squares method, which requires repeated iterations, and the calculation amount, error and power loss are relatively large. And less power consumption.

In a possible design, the method further includes: detecting the current of the battery at 2n times after the first time, respectively; and determining whether to stop charging the battery according to the current of the battery at the 2n times.

When the voltage of the battery is detected at 2n times after the first time, the current flowing through the battery can be detected, which can be used to judge whether the detected current of the battery at 2n times is 0, so as to judge whether the charging stop is normal. If the current of the battery is 0 at 2n times, it means that the charging current disappears instantly, and the charging stop is normal. Otherwise, as long as the current at one of the 2n times is not 0, it means that the charging current does not disappear instantaneously, and an abnormality occurs when the charging is stopped.

In a second aspect, an embodiment of the present application provides a battery parameter detection device, which can be applied to terminal devices such as mobile phones and tablet computers, and is used to implement the method described in the first aspect above. The battery parameter detection device includes: a processing module and a sampling circuit. The processing module is connected with the sampling circuit, and is used to control the sampling circuit to detect the current and voltage of the battery at the first moment, and the first moment is the moment when the battery is charged; the processing module is also used to control the charging circuit of the battery to stop charging the battery ; The processing module is also used to control the sampling circuit to detect the voltage of the battery at 2n moments after the first moment; wherein, the first moment and any two adjacent moments in the 2n moments are separated by the first duration, and n is greater than or an integer equal to 1; the processing module is further configured to determine the battery parameters of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n moments, and the first duration; the battery parameters of the battery include at least one of the following Species: AC resistance ACR, DC resistance DCR, electrochemical impedance spectroscopy EIS, and polarization time constant.

In a possible design, the processing module is specifically configured to determine 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 moment, the voltage of the battery at 2n moments, and the first duration; The battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery.

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

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 equations;

In one possible design, the processing module is specifically used to determine the ACR of the battery according to the following equation;

In one possible design, the processing module is specifically used to determine the DCR of the battery according to the following equation;

Among them, ΔT represents a fixed discharge time and is a constant.

In one possible design, the processing module is specifically used to determine the EIS of the battery according to the following equation;

Among them, f represents the 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.

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

In a possible design, the processing module is further configured to control the sampling circuit to detect the current of the battery at 2n times after the first time, and determine whether to stop charging the battery according to the current of the battery at 2n times.

In a third aspect, an embodiment of the present application provides an electronic device, where the electronic device may be a terminal device such as a mobile phone and a tablet computer. The electronic device includes: a processor, a memory for storing instructions executable by the processor; when the processor is configured to execute the instructions, the electronic device causes the electronic device to implement the method according to the first aspect. Among them, the electronic equipment is provided with a battery and a sampling circuit.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium on which computer program instructions are stored; when the computer program instructions are executed by an electronic device, the electronic device is made to implement the method described in the first aspect. Among them, the electronic equipment is provided with a battery and a sampling circuit.

In a fifth aspect, the embodiments of the present application provide a computer program product, including computer-readable codes, which, when the computer-readable codes are executed in an electronic device, enable the electronic device to implement the method described in the foregoing first aspect. Among them, the electronic equipment is provided with a battery and a sampling circuit.

For the beneficial effects of the second aspect to the fifth aspect, reference may be made to the description in the first aspect, which will not be repeated here.

It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it can be understood that the description of features or beneficial effects means that a specific technical feature, technical solution or beneficial effect is included in at least one embodiment. Therefore, descriptions of technical features, technical solutions or beneficial effects in this specification do not necessarily refer to the same embodiments. Furthermore, the technical features, technical solutions and beneficial effects described in this embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that an embodiment can be implemented without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and benefits may also be identified in specific embodiments that do not embody all embodiments.

Description of drawings

1 shows a schematic flowchart of a battery parameter detection method provided by an embodiment of the present application;

FIG. 2 shows a schematic diagram of detection results of voltage and current of a battery provided by an embodiment of the present application;

FIG. 3 shows a schematic structural diagram of an n-order impedance equivalent circuit model provided by an embodiment of the present application;

FIG. 4 shows a schematic structural diagram of a second-order impedance equivalent circuit model provided by an embodiment of the present application;

FIG. 5 shows a schematic diagram of the detection results of the voltage and current of another battery provided by the embodiment of the present application;

6 shows a schematic structural diagram of a first-order impedance equivalent circuit model provided by an embodiment of the present application;

FIG. 7 shows a schematic diagram of detection results of voltage and current of another battery provided by an embodiment of the present application;

8 shows a schematic structural diagram of a battery parameter detection circuit;

FIG. 9 shows a schematic structural diagram of a battery parameter detection device.

detailed description

In the existing detection of battery parameters such as ACR, DCR, EIS, polarization time constant, etc., it is generally necessary for the system (that is, the circuit system where the battery is located, hereinafter referred to as the system) to load a periodic square wave or sine wave current to the battery. Or pull a constant current. However, during the use of the battery, the current drawn by the system is irregular, and it is difficult to realize the periodic square wave or sine wave current, constant current and so on. Therefore, the prior art solution needs to be carried out under the condition that the charger of the battery is in place but not charging, and the detection of battery parameters cannot be realized during the battery charging process. Against this background, an embodiment of the present application provides a battery parameter detection method, which can be applied to a terminal device (or referred to as an 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 : TV), car machine (such as: car computer), smart screen, game console, headset, artificial intelligence (artificial intelligence, AI) speakers, and augmented reality (AR) / virtual reality (virtual reality, VR) equipment, etc. This embodiment does not limit the specific equipment form of the terminal equipment.

The battery parameter detection method includes: detecting the current and voltage of the battery at a first moment, where the first moment is the moment when charging the battery; stopping charging the battery; and detecting the voltage of the battery at 2n moments after the first moment. ; Among them, the first time interval between any two adjacent moments in the first moment and 2n moments is the first duration, and n is an integer greater than or equal to 1; according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n moments , and the first duration to determine battery parameters of the battery. For example, the battery parameters of the battery may include at least one of the following: ACR, DCR, EIS, and polarization time constant.

The battery parameter detection method provided by the embodiment of the present application is exemplarily described below. It should be noted that, in the description of this application, "at least one" refers to one or more, and "a plurality" refers to two or more. The words "first" and "second" are only for distinguishing descriptions, and are not used to specifically limit a certain feature, that is, the first or the second may include more contents, rather than being limited to a specific concept . "And/or" is used to describe the association relationship of associated objects, indicating that there are three kinds of relationships. For example, A and/or B can mean that A exists alone, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects are an "or" relationship. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field in this application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application.

FIG. 1 shows a schematic flowchart of a battery parameter detection method provided by an embodiment of the present application. As shown in FIG. 1 , the battery parameter detection method includes: S101-S105. S101. Detect the current and voltage of the battery at a first moment, where the first moment is the moment when the battery is charged.

The first moment refers to the moment when battery parameter detection is initiated. For example, the current and voltage of the battery can be detected at the moment when the detection is started. Taking the method applied to a mobile phone as an example, initiating battery parameter detection may be that the mobile phone initiates battery parameter detection on the battery in response to the user's operation, or the mobile phone may follow a certain preset period (such as: one day, one week, one month, etc.) , automatically initiate battery parameter detection. The embodiments of the present application do not limit the conditions for initiating battery parameter detection.

Optionally, at the first moment, the charge level of the battery may be a certain value between 0-100%, such as: 8%, 40%, 51%, etc., or it may also be 100%, here No restrictions apply.

S102, stop charging the battery. S103. Detect the voltage of the battery at 2n moments after the first moment; wherein, the first moment and any two adjacent moments in the 2n moments are separated by a first duration, and n is an integer greater than or equal to 1. Optionally, the first duration may be 0.05 milliseconds (ms), 0.1 ms, 0.5 ms, 1 ms, etc. The size of the first duration is not limited in this application.

Taking the method applied to a mobile phone as an example, a sampling circuit may be provided in the mobile phone. The specific process of S101-S103 may be as follows: at a certain first moment in the process of charging the battery by the mobile phone, the mobile phone may detect the current and voltage of the battery through the sampling circuit. After detecting the current and voltage of the battery at the first moment, the mobile phone can control the charging circuit of the battery to stop charging the battery. After stopping the charging of the battery, the mobile phone can detect the voltage of the battery through the sampling circuit at 2n times after the first time.

For example, if the first moment is t0 and the first duration is m, then the first moment t1 of the 2n moments is t0+m, the second moment t2 of the 2n moments is t0+2m, and the second moment of the 2n moments is t0+2m. The third time t3 is t0+3m, and so on, the 2nth time t2n among the 2n times is t0+2nm.

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

After the current and voltage of the battery at the first moment and the voltage of the battery at 2n times are detected through S101-S103, the current and voltage of the battery at the first moment, the voltage of the battery at 2n times, and the first duration , determine the battery parameters of the battery. For example, S104 and S105 can be executed.

S104: Determine parameters of an n-order impedance equivalent circuit model of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n times, and the first duration. Among them, n in the n-order impedance equivalent circuit model of the battery refers to n in the above-mentioned 2n times. For example, if the impedance equivalent circuit model of the battery is selected as the second-order impedance equivalent circuit model, in the above S103, the voltage of the battery is detected at 2*2=4 times after the first time. Any two adjacent moments in the four moments are separated by the first duration. If the impedance equivalent circuit model of the battery is selected as the first-order impedance equivalent circuit model, in the above S103, the voltage of the battery is detected respectively at 2*1=2 times after the first time, the first time and these two Any two adjacent moments in the moment are separated by the first time period.

FIG. 3 shows a schematic structural diagram of an n-order impedance equivalent circuit model provided by an embodiment of the present application. As shown in Figure 3, the n-order impedance equivalent circuit model of the battery can be equivalent to the series connection of resistor R0 and n-order parallel RC network, such as: resistor R1 and capacitor C1 are connected in parallel to form the first RC network, resistor R2 and capacitor C2 The second RC network is formed in parallel, and so on, the resistor Rn and the capacitor Cn are connected in parallel to form the nth RC network; the resistor R0 can be connected in series with the aforementioned n RC networks in sequence to form an n-order impedance equivalent circuit model.

For the n-order impedance equivalent circuit model shown in FIG. 3, the current and voltage of the battery at the first moment, the voltage of the battery at 2n moments, and the first moment and 2n moments can be obtained according to the above S101-S103 detection. In the first time interval of any two adjacent time intervals, the parameter R0, the parameters R1 to Rn, and the parameters τ1 to τn of the n-order impedance equivalent circuit model are determined. The parameter R0 of the n-order impedance equivalent circuit model can be obtained by substituting the current and voltage of the battery at the first moment into the following formula (6).

R0=(Vbat(1)-Vbat(0))/I (6)

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

After the parameter R0 is calculated, R0, the current and voltage of the battery at the first moment, the voltage of the battery at 2n times, and the first duration can be substituted into the following formula (7) for calculation to obtain the equivalent of n-order impedance. Parameters R1 to Rn of the circuit model, and parameters τ1 to τn.

In formula (7), Vbat(0) represents the voltage of the battery at the first moment; Vbat(1) to Vbat(2n) respectively represent the battery at 2n moments (from the 1st moment to the 2nth moment in the 2n moments) time); I represents the current of the battery at the first time; t represents the first duration; e is a natural constant.

S105. Determine 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 and parameters R1 to Rn 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 moment, the voltage of the battery at 2n moments, and the first duration , and parameters τ1 to τn. In this application, after the parameters R0, R1 to Rn, and τ1 to τn of the n-order impedance equivalent circuit model of the battery are obtained, the parameters R0, R1 to Rn, and τ1 to τn can be determined respectively according to the parameters R0, R1 to Rn, and τ1 to τn. Battery parameters such as ACR, DCR, EIS, polarization time constant, etc. of the battery. The specific process of determining the ACR, DCR, EIS, and polarization time constant of the battery according to the parameter R0, the parameters R1 to Rn, and the parameters τ1 to τn, respectively, will be described below.

1) For ACR, the ACR of the battery can be obtained by substituting the parameter R0, the parameters R1 to Rn, and the parameters τ1 to τn into the following formula (8), and then calculating the equation result obtained by substituting the formula (8).

2) For DCR, the DCR of the battery can be obtained by substituting the parameter R0, the parameters R1 to Rn, and the parameters τ1 to τn into the following formula (9), and then calculating the equation result obtained by substituting the formula (9).

In the formula (9), ΔT represents a fixed discharge time and is a constant. For example, ΔT may be 1 second, 3 seconds, etc. When ΔT is 1 second, the DCR of the battery corresponding to a discharge time of 1 second can be calculated. When ΔT is 3 seconds, the DCR of the battery corresponding to a discharge time of 3 seconds can be calculated. In the embodiment of the present application, ΔT can be determined according to the DCR of the battery corresponding to the required discharge time. Entering different ΔT can obtain the DCR of the battery corresponding to different discharge times.

3) For EIS, it can be obtained by substituting parameters R0, parameters R1 to Rn, and parameters τ1 to τn into the following formulas (10) and (11), and then calculating the Equation results, you can get the EIS of the battery.

In formula (10) and 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.

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

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

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

The following takes the typical model of the lithium-ion battery of the mobile phone: the second-order impedance equivalent circuit model (that is, n in the n-order impedance equivalent circuit model of the battery is 2) as an example, the specific implementation process of the battery parameter detection method Give an example.

FIG. 4 shows a schematic structural diagram of a second-order impedance equivalent circuit model provided by an embodiment of the present application. As shown in Figure 4, the equivalent circuit model of the second-order impedance of the battery can be equivalent to the series connection of the resistor R0 and the second-order parallel RC network, such as: the resistor Re and the capacitor Ce are connected in parallel to form the first RC network, the resistor Rp and the capacitor Cp The second RC network is formed in parallel; the resistor R0 can be connected in series with the aforementioned two RC networks in turn to form a second-order impedance equivalent circuit model.

When the impedance equivalent circuit model of the battery is the second-order impedance equivalent circuit model shown in FIG. 4 , the specific implementation process of the battery parameter detection method is: at a certain first moment when the battery is charged (marked as moment 0) ), detect the current and voltage of the battery; then, stop charging the battery; after stopping the charging of the battery, take time 0 as the starting time, every first time period (denoted as t), that is, take t as the cycle, in turn The voltage of the battery is detected respectively at four time points after time 0 (referred to as time t, time 2t, time 3t, and time 4t in sequence).

If the voltage of the battery at time 0 is expressed as Vbat(0), the voltage of the battery at time t is expressed as Vbat(1), the voltage of the battery at time 2t is expressed as Vbat(2), and the voltage of the battery at time 3t is expressed as Vbat (3), the voltage of the battery at time 4t is expressed as Vbat(4), the current of the battery at time 0 is expressed as I, then the current and voltage of the battery at time 0, and the battery at time t, time 2t, time 3t, and The detection result of the voltage at time 4t can be shown in FIG. 5 .

After obtaining the voltage Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4) corresponding to the above battery from time 0 to time 4t, and the current I of the battery at time 0, you can First, substitute Vbat(0), Vbat(1), and I into formula (6), and calculate the parameter R0 of the second-order impedance equivalent circuit model.

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

R0=(Vbat(1)-Vbat(0))/I.

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

Then, R0, Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4), and I can be substituted into formula (7) to calculate the parameters of the second-order impedance equivalent circuit model (Re, τe), (Rp, τp). Among them, (Re, τe) is (R1, τ1) when n=2 in the n-order impedance equivalent circuit model, and (Rp, τp) is (R2, τ2) when n=2.

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

By calculating the equation system, the parameters (Re, τe) and (Rp, τp) of the second-order impedance equivalent circuit model can be obtained.

It can be seen that in this equation system, R0, Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4), and I are all known quantities. Then, the solution process of the system of equations can be as follows.

First, each term of this system of equations can be divided by I, deforming it as:

For the transformed equation system, (Vbat(0)-Vbat(1))/I-R0 in the first equation can be recorded as K1. Denote (Vbat(0)-Vbat(2))/I-R0 in the second equation as K2. Record (Vbat(0)-Vbat(3))/I-R0 in the third equation as K3; record (Vbat(0)-Vbat(4))/I-R0 in the fourth equation as K4.

At this point, the system of equations can be further transformed into:

In this further deformed equation system, since R0, Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4), and I are all known quantities, K1, The values of K2, K3, and K4 can be easily calculated.

Suppose that in the above-mentioned further deformed equation system, denoted as

Denoted as y, the following equation can be obtained according to the above-mentioned further deformed equation system.

a*y ² +b*y+c=0.

In this equation, a=K1*K2+K1*K3-K12 ^- K22 ^; b=K1*K2 ⁺ K2*K3-K22-K1*K4; c=K1*K3+K2*K3+K2*K4 -K2 ² -K3 ² -K1*K4.

Solving this equation, we get:

Substituting y into the above system of equations, we get:

Further, according to x and y, we can get:

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

After substituting R0, (Re, τe), (Rp, τp), formula (8) can be expressed as the following equation:

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

Similarly, the parameters R0, (Re, τe), (Rp, τp) can also be substituted into formula (9) to calculate the DCR of the battery.

After substituting R0, (Re, τe), (Rp, τp), formula (9) can be expressed as the following equation:

Among them, ΔT represents a fixed discharge time, which is a constant (for details, please refer to the description in the foregoing embodiment). By calculating this equation, the DCR of the battery can be obtained.

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

After substituting R0, (Re, τe), (Rp, τp), formula (10) and formula (11) can be expressed as the following two equations:

By substituting f in the above two equations into different values, such as: 1 Hz, 1/2 Hz, etc., EIS _Re and EIS _Im at different frequencies can be obtained. 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.

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

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 (called SEI polarization time constant), and the larger one is the polarization time constant of the electrochemical reaction (called the electrochemical polarization time constant).

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

SEI polarization time constant=min{τe,τp}, min{} means taking the minimum value in {}; electrochemical polarization time constant=max{τe, τp}, max{} means taking the value in {} maximum value.

In some possible examples, the above-mentioned second-order impedance equivalent circuit model can also be replaced with a simplified lithium-ion battery model: the first-order impedance equivalent circuit model, that is, n in the n-order impedance equivalent circuit model of the battery above is 1. The following takes the first-order impedance equivalent circuit model as an example to illustrate the specific implementation process of the battery parameter detection method.

FIG. 6 shows a schematic structural diagram of a first-order impedance equivalent circuit model provided by an embodiment of the present application. As shown in Figure 6, the equivalent circuit model of the first-order impedance of the battery can be equivalent to the series connection of the resistor R0 and the first-order parallel RC network. For example, 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 a first-order impedance equivalent circuit model.

When the impedance equivalent circuit model of the battery is the first-order impedance equivalent circuit model shown in Figure 6, the specific implementation process of the battery parameter detection method is: at a certain first moment when the battery is charged (also recorded as 0 time), detect the current and voltage of the battery; then, stop charging the battery; after stopping charging the battery, take time 0 as the starting time, every first time period (denoted as t), that is, take t as the cycle, The voltage of the battery is respectively detected at two time points after time 0 (referred to as time t and time 2t in sequence).

If the voltage of the battery at time 0 is expressed as Vbat(0), the voltage of the battery at time t is expressed as Vbat(1), the voltage of the battery at time 2t is expressed as Vbat(2), and the current of the battery at time 0 is expressed as I , the detection results of the current and voltage of the battery at time 0, and the voltage of the battery at time t and time 2t can be shown in FIG. 7 .

After obtaining the voltages Vbat(0), Vbat(1), Vbat(2) corresponding to the above-mentioned battery from time 0 to time 2t, and the current I of the battery at time 0, Vbat(0), Vbat( 1), and I are substituted into formula (6), and the parameter R0 of the first-order impedance equivalent circuit model is obtained by calculation.

R0=(Vbat(1)-Vbat(0))/I.

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

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

By calculating the equation system, the parameters (Re, τe) of the second-order impedance equivalent circuit model can be obtained.

It can be seen that in this system of equations, R0, Vbat(0), Vbat(1), Vbat(2), and I are all known quantities. Then, the solution process of the system of equations can be as follows.

For the transformed equation system, (Vbat(0)-Vbat(1))/I-R0 in the first equation can be recorded as K1. Denote (Vbat(0)-Vbat(2))/I-R0 in the second equation as K2.

At this point, the system of equations can be further transformed into:

In this further deformed equation system, since R0, Vbat(0), Vbat(1), Vbat(2), and I are all known quantities, the values of K1, K2, K3, and K4 can be easily Calculated.

Suppose that in the above further deformed system of equations,

Denoted as y, then according to the above-mentioned further deformed equations, we can get:

Substituting y into the above system of equations, we get:

After obtaining the parameters R0 and (Re, τe) of the first-order impedance equivalent circuit model, the parameters R0 and (Re, τe) can be substituted into formula (8) to calculate the ACR of the battery.

After substituting R0 and (Re, τe), formula (8) can be expressed as the following equation:

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

Similarly, the parameters R0 and (Re, τe) can also be substituted into formula (9) to calculate the DCR of the battery.

After substituting R0 and (Re, τe), formula (9) can be expressed as the following equation:

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

After substituting R0 and (Re, τe), formula (10) and formula (11) can be expressed as the following two equations:

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

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

To sum up, the battery parameter detection method provided by the embodiment of the present application can reduce the detection conditions of the battery parameters, and realize the detection of the battery parameters during the battery charging process, so that the battery parameters of the battery can be acquired in real time, and the battery parameters can be detected in time. It can reduce the possible abnormality of the battery, thereby reducing the life attenuation and even safety accidents caused by the improper use of the battery, and bringing a better user experience to the user.

Some possible hardware structures for implementing the battery parameter detection method will be exemplarily described below with reference to FIG. 8 . FIG. 8 shows a schematic structural diagram of a battery parameter detection circuit. As shown in FIG. 8 , the battery parameter detection circuit may 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 to the battery 10; the control module 30 is connected to the charging circuit 20 for controlling the charging circuit 20 to charge or stop charging the battery 10; the control module 30 is also connected to the sampling circuit 40, and is used to control the sampling circuit 40 The voltage across the battery 10, and/or the current flowing through the battery 10, is collected. The calculation module 50 is connected to the sampling circuit 40, and is used for receiving or acquiring the voltage and current data collected by the sampling circuit 40, and calculating battery parameters according to a preset algorithm.

For example, at a certain first moment in the process of charging the battery 10 by the charging circuit 20, the control module 30 may 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 moment, Thus, S101 shown in FIG. 1 is realized. Then, the control module 30 may send a charge stop signal to the charging circuit 20, and after receiving the charge stop signal, the charging circuit 20 stops charging the battery 10, thereby implementing S102 shown in FIG. 1 above. Then, at 2n times after the first time (refer to the foregoing embodiments for details), the control module 30 may send a trigger signal to the sampling circuit 40 at each of the 2n times, respectively, to control the sampling circuit 40 . The voltage of the battery at 2n times is detected, so as to realize S103 shown in FIG. 1 above. The calculation module 50 can receive or read the current and voltage of the battery at the first moment, the voltage of the battery at 2n times, and the first duration collected by the sampling circuit 40, and calculate the n-order impedance of the battery according to a preset algorithm, etc. The parameters of the effective circuit model, and the battery parameters of the battery are calculated according to the parameters of the calculated n-order impedance equivalent circuit model of the battery. Thus, S104 and S105 shown in FIG. 1 above are realized. 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 moment, the voltage of the battery at 2n times, and the first duration in the foregoing embodiment, 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.

It can be understood that the structure shown in FIG. 8 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 computing module 50 may also be an integrated module, such as a CPU. The sampling circuit 40 may further include: an amplifying circuit for amplifying the detected signal. Alternatively, the control module 30 and/or the computing module 50 may also be divided into more sub-modules and the like. In other embodiments, the charging circuit 20 , the control module 30 , the sampling circuit 40 , the calculation module 50 , etc., may also be all integrated into one power management chip. In other words, the structure shown in FIG. 8 may actually include more or less components than those shown in FIG. 8 , or combine some components, or separate some components, or different component arrangements, and so on. Alternatively, some of the components shown in FIG. 8 may be implemented in hardware, software, or a combination of software and hardware. This application does not limit this.

Optionally, the battery parameter detection method provided by the embodiment of the present application may further include: detecting the current of the battery at 2n times after the first time, and determining whether the battery stops charging according to the current of the battery at 2n times.

That is, in S103 shown in FIG. 1 , when the voltage of the battery is detected at 2n time points after the first time point, the current flowing through the battery can also be detected. Under normal circumstances, since the battery is stopped from charging after the voltage and current of the battery are detected at the first time, the current of the battery should be 0 at 2n times after the first time. Therefore, in the embodiment of the present application, the current of the battery is detected at 2n times after the first time, which can be used to judge whether the detected current of the battery at 2n times is 0, so as to judge whether the charging stop is normal (stop Charging means stopping charging). If the current of the battery is 0 at 2n times, it means that the charging current disappears instantly (that is, the charging is stopped), and the charging is normal. Otherwise, as long as the current at one of the 2n times is not 0, it means that the charging current does not disappear instantaneously (that is, the charging is not stopped), and an abnormality occurs when the charging is stopped.

Optionally, for a terminal device (such as a mobile phone), when charging is stopped abnormally, it may indicate that there is a problem with the battery or the power management chip, and the terminal device can send relevant prompt information to the user, for example, the prompt information can be a prompt to the user. Restarting the terminal device, or restarting battery parameter detection, or prompting the user to restart the terminal device, or only prompting that the battery is abnormal, etc., the content of the prompt information is not limited in this application. Of course, on different terminal devices, when charging stops abnormally, the terminal device may take more different measures, which can be configured by users or developers, and will not be described in detail.

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

In addition, in the current DCR detection, the power consumption is increased by pulling the constant current for a period of time, while the embodiment of the present application does not need to pull the constant current, which relatively reduces the power consumption. The current EIS needs to be measured once per frequency, and the overall test time is long (for example, it takes about 2 minutes to measure from 1000Hz to 1Hz), and the user experience is poor. The current data can be calculated in combination with the algorithm to obtain the EIS of the battery, which can effectively improve the user experience. The current battery polarization time constant calculation adopts the least squares method, which requires repeated iterations, and the calculation amount, error and power loss are relatively large. And less power consumption.

From the perspective of cost, in the current detection methods of battery parameters such as ACR, DCR, EIS, polarization time constant, etc., if ACR, DCR, and EIS are tested at the same time, it is necessary to develop corresponding modules, and each module has different requirements for excitation current. , voltage/current sampling rate and sampling accuracy requirements are also different. For example, ACR detection needs to pull a sine wave or square wave, and DCR detection needs to pull a constant current. The development of their respective modules will increase the cost of area and wiring. However, in the battery parameter detection method provided in the embodiment of the present application, by detecting the voltage and current data of the battery, ACR, DCR, EIS, polarization time constant, etc. can be calculated at the same time, so the development cost can be effectively reduced.

Corresponding to the methods described in the foregoing embodiments, the embodiments of the present application further provide a battery parameter detection apparatus that can be applied to a terminal device. For example, FIG. 9 shows a schematic structural diagram of a battery parameter detection device. As shown in FIG. 9 , the device includes: a processing module 901 and a sampling circuit 902 . The processing module 901 is connected to the sampling circuit 902, and is used to control the sampling circuit 902 to detect the current and voltage of the battery at the first moment, and the first moment is the moment when the battery is charged; the processing module 901 is also used to control the charging circuit of the battery Stop charging the battery; the processing module 901 is also used to control the sampling circuit to detect the voltage of the battery at 2n moments after the first moment; duration, n is an integer greater than or equal to 1; the processing module 901 is further configured to determine the battery parameters of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at 2n moments, and the first duration; The battery parameters include at least one of the following: alternating current resistance ACR, direct current resistance DCR, electrochemical impedance spectroscopy EIS, and polarization time constant.

In a possible design, the processing module 901 is specifically configured to determine 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 moment, the voltage of the battery at 2n moments, and the first duration ; Determine the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery.

In a possible design, the processing module 901 is specifically used for:

According to the current and voltage of the battery at the first moment and the voltage of the battery at the first moment of the 2n moments, determine the parameter R0 of the n-order impedance equivalent circuit model of the battery;

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

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

Among them, ΔT represents a fixed discharge time and is a constant.

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

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

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 times after the first time, and determine whether the battery stops charging according to the current of the battery at 2n times.

It should be understood that the division of the processing module 901 in the above apparatus is only a division of logical functions, for example, the processing module 901 may include a control module and a calculation module. In actual implementation, the processing module 901 may be integrated into one physical entity in whole or in part, or may be physically separated. And the processing modules 901 in the device can all be implemented in the form of software calling through processing elements; also can all be implemented in hardware; some units can also be implemented in the form of software calling through processing elements, and some units can be implemented in hardware.

For example, the processing module 901 can be a separately established processing element, or can be integrated in a certain chip of the device to be implemented, and can also be stored in the memory in the form of a program, and the unit can be called and executed by a certain processing element of the device. function. In addition, all or part of these units can be integrated together, and can also be implemented independently. The processing element described here may also be called a processor, which may be an integrated circuit with signal processing capability. In the implementation process, each step of the above method or each of the above units may be implemented by an integrated logic circuit of hardware in the processor element or implemented in the form of software being invoked by the processing element.

In one example, the processing module 901 in the above apparatus may be one or more integrated circuits configured to implement the above method, such as: one or more ASICs, or, one or more DSPs, or, one or more FPGA, or a combination of at least two of these integrated circuit forms.

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 processors that can call programs. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

In one implementation, the processing module 901 in the above apparatus may be implemented in the form of a processing element scheduler. For example, the processing module 901 may include a processing element and a storage element, and the processing element invokes a program stored in the storage element to implement the function of the processing module 901 . The storage element may be a storage element on the same chip as the processing element, ie, an on-chip storage element.

In another implementation, the program for realizing the functions of the processing module 901 in the above apparatus may be in a storage element on a different chip from the processing element, ie, an off-chip storage element. At this time, the processing element calls or loads the program from the off-chip storage element to the on-chip storage element, so as to call and execute the methods described in the above method embodiments.

For example, an embodiment of the present application may further provide an apparatus, such as an electronic device, which may include a processor, a memory for storing instructions executable by the processor. When the processor is configured to execute the above-mentioned instructions, the electronic device enables the electronic device to implement the method described in the foregoing embodiments. The memory may be located within the electronic device or external to the electronic device. And the processor includes one or more. Among them, the electronic equipment is provided with a battery and a sampling circuit.

In yet another implementation, the unit of the apparatus implementing each step in the above method may be configured as one or more processing elements, and these processing elements may be provided on the terminal corresponding to the above-mentioned battery, and the processing elements here may be integrated Circuits, such as: one or more ASICs, or, one or more DSPs, or, one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits can be integrated together to form chips.

For example, an embodiment of the present application further provides a chip, which can be applied to the above-mentioned terminal device. The chip includes one or more interface circuits and one or more processors; the interface circuit and the processor are interconnected by lines; the processor receives and executes computer instructions from the memory of the electronic device through the interface circuit, so as to realize the above method embodiments. Methods.

From the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above functional modules is used as an example for illustration. In practical applications, the above functions can be allocated as required. It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules, so as to complete all or part of the functions described above.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be Incorporation may either be integrated into another device, or some features may be omitted, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place, or may be distributed to multiple different places . Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application essentially or contribute to the prior art, or all or part of the technical solutions may be embodied in the form of software products, such as programs. The software product is stored in a program product, such as a computer-readable storage medium, and includes several instructions to cause a device (which may be a single-chip microcomputer, a chip, etc.) or a processor (processor) to execute all of the methods described in the various embodiments of the present application. or part of the steps. The aforementioned storage medium includes: a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk, and other media that can store program codes.

For example, the embodiments of the present application may further provide a computer-readable storage medium on which computer program instructions are stored. When executed by the electronic device, the computer program instructions cause the electronic device to implement the methods described in the foregoing method embodiments. Among them, the electronic equipment is provided with a battery and a sampling circuit.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this, and any changes or substitutions within the technical scope disclosed in the present application should be covered within 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

A method for detecting battery parameters, comprising:

At a first moment, the current and voltage of the battery are detected, and the first moment is the moment when the battery is charged;

stop charging the battery;

Detect the voltage of the battery at 2n moments after the first moment, respectively; wherein, the first moment and any two adjacent moments in the 2n moments are separated by a first duration, and n is greater than or equal to an integer of 1;

determining the battery parameters of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration;

The battery parameters of the battery include at least one of the following: alternating current resistance ACR, direct current resistance DCR, electrochemical impedance spectroscopy EIS, and polarization time constant.
The method according to claim 1, wherein the determining is based on the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration. The battery parameters of the battery, including:

According to the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration, determine the parameters of the n-order impedance equivalent circuit model of the battery;

The battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery.
The method according to claim 2, wherein the determining is based on the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration. The parameters of the n-order impedance equivalent circuit model of the battery include:

According to the current and voltage of the battery at the first moment and the voltage of the battery at the first moment of the 2n moments, determine the parameter R0 of the n-order impedance equivalent circuit model of the battery;

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 equations;

Wherein, Vbat(0) represents the voltage of the battery at the first moment; Vbat(1) to Vbat(2n) represent the voltage of the battery at the 2n moments respectively; I represents the battery at the The current at the first moment; t represents the first duration; e is a natural constant.
The method according to claim 3, wherein the determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises:

The ACR of the battery is determined according to the following equation;
The method according to claim 3 or 4, wherein, determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery, comprising:

The DCR of the battery is determined according to the following equation;

Among them, ΔT represents a fixed discharge time and is a constant.
The method according to any one of claims 3-5, wherein the determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises:

Determine the EIS of the battery according to the following equation;

Wherein, f represents the 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.
The method according to any one of claims 3-6, wherein the determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises:

The parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery are determined as the polarization time constant of the battery.
The method according to any one of claims 1-7, wherein the method further comprises:

Detecting the current of the battery at 2n moments after the first moment, respectively;

According to the current of the battery at the 2n times, it is determined whether the battery stops charging.
A battery parameter detection device, comprising: a processing module and a sampling circuit;

The processing module is connected to the sampling circuit, and is configured to control the sampling circuit to detect the current and voltage of the battery at a first moment, where the first moment is the moment when the battery is charged;

The processing module is further configured to control the charging circuit of the battery to stop charging the battery;

The processing module is further configured to control the sampling circuit to detect the voltage of the battery at 2n moments after the first moment; wherein, any two phases of the first moment and the 2n moments are in phase. The first duration of the adjacent time interval, n is an integer greater than or equal to 1;

The processing module is further configured to determine battery parameters of the battery according to the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the first duration;

The battery parameters of the battery include at least one of the following: alternating current resistance ACR, direct current resistance DCR, electrochemical impedance spectroscopy EIS, and polarization time constant.
The device according to claim 9, wherein the processing module is specifically configured to calculate the current and voltage of the battery at the first moment, the voltage of the battery at the 2n moments, and the For the first duration, parameters of the n-order impedance equivalent circuit model of the battery are determined; battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery.
The device according to claim 10, wherein the processing module is specifically configured to:

According to the current and voltage of the battery at the first moment and the voltage of the battery at the first moment of the 2n moments, determine the parameter R0 of the n-order impedance equivalent circuit model of the battery;

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 equations;

Wherein, Vbat(0) represents the voltage of the battery at the first moment; Vbat(1) to Vbat(2n) represent the voltage of the battery at the 2n moments respectively; I represents the battery at the The current at the first moment; t represents the first duration; e is a natural constant.
The device according to claim 11, wherein the processing module is specifically configured to determine the ACR of the battery according to the following equation;
The device according to claim 11 or 12, wherein the processing module is specifically configured to determine the DCR of the battery according to the following equation;

Among them, ΔT represents a fixed discharge time and is a constant.
The device according to any one of claims 11-13, wherein the processing module is specifically configured to determine the EIS of the battery according to the following equation;

Wherein, f represents the 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.
The device according to any one of claims 11-14, wherein the processing module is specifically configured to determine that the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery are the polarization time of the battery constant.
The device according to any one of claims 9-15, wherein the processing module is further configured to control the sampling circuit to detect the current of the battery at 2n times after the first time, and According to the current of the battery at the 2n times, it is determined whether the battery stops charging.