Polarization Voltage Determination Method, Device, Vehicle, and Equipment

Abstract

The present application relates to a method, a device, a vehicle and a device for determining a polarization voltage, and relates to the technical field of batteries. The method includes: obtaining battery parameters of a target battery; the battery parameters include charge-discharge parameters of the target battery in a charge-discharge state and a rest time in a rest state; determining an electrochemical polarization voltage and an ohmic polarization voltage of the target battery based on the battery parameters; and determining a polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage. Thus, the polarization voltage of the battery can be accurately calculated.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, in particular to the technical field of battery polarization voltage, and specifically relates to a method, device, vehicle and equipment for determining polarization voltage. Background Art

[0002] The terminal voltage collected by a battery management system (BMS) includes battery polarization voltage and balance voltage. Among them, the balance voltage, as a direct reflection of the thermodynamic performance of the electrode material, is the voltage value of the battery in theory without external interference. The polarization voltage represents the deviation between the terminal voltage and the balance voltage of the battery under actual working conditions. The accurate calculation of the polarization voltage helps the BMS to more accurately grasp the actual working state of the battery, so as to achieve accurate management of the battery. However, due to the polarization voltage being affected by various factors, it is difficult to calculate the polarization voltage of the battery.

[0003] In a related technology, a method for calculating the polarization voltage of a battery by multiplying the sum of current and the increment of internal resistance is proposed. However, the polarization voltage calculated by this method will increase linearly with time, which does not conform to the actual result.

[0004] In another related technology, a method for obtaining the polarization voltage at the time of battery pack power-off based on looking up a table in a polarization voltage database is proposed. This scheme first establishes a polarization voltage database and obtains the polarization voltage value at this time by looking up the table. However, this method is too dependent on the accuracy of the offline calibrated database and the state of charge (SOC). Summary of the Invention

[0005] The present application provides a method, device, vehicle and equipment for determining polarization voltage to at least solve the technical problem in the related technology that it is difficult to accurately calculate the polarization voltage of a battery. The technical solution of the present application is as follows:

[0006] According to the first aspect provided by the present application, a method for determining polarization voltage is provided, including: obtaining battery parameters of a target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a static time in a static state; determining the electrochemical polarization voltage and ohmic polarization voltage of the target battery based on the battery parameters; and determining the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0007] According to the above technical means, the present application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charge and discharge process, based on the battery parameters (including charge and discharge parameters and static time) of the target battery, so as to accurately determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery.

[0008] In a possible implementation, the electrochemical polarization voltage includes: the electrochemical polarization accumulation voltage generated by the target battery during charge and discharge states and the electrochemical polarization elimination voltage generated by the target battery during the rest state.

[0009] According to the above technical means, the present application can distinguish the electrochemical polarization voltage into an electrochemical polarization accumulation voltage and an electrochemical polarization elimination voltage according to the construction process, so as to accurately calculate the electrochemical polarization voltage of the target battery.

[0010] In a possible implementation, the following method is used to determine the electrochemical polarization accumulation voltage: based on the first mapping relationship, determine the first target polarization parameter that matches the charge and discharge parameters; the first mapping relationship includes: a plurality of first polarization parameters corresponding one-to-one to a plurality of charge and discharge parameters; the first polarization parameter is the polarization parameter measured during the electrochemical polarization accumulation process of the battery; based on the charge and discharge parameters and the first target polarization parameter, determine the electrochemical polarization accumulation voltage.

[0011] According to the above technical means, the present application can pre-establish the first mapping relationship through measured data, so as to directly find the first target polarization parameter that matches it according to the charge and discharge parameters, and further accurately calculate the electrochemical polarization accumulation voltage according to the first target polarization parameter and the charge and discharge parameters.

[0012] In a possible implementation, the first polarization parameter includes the rate of electrochemical polarization accumulation of the battery.

[0013] According to the above technical means, the present application can accurately reflect the accumulation speed of the polarization phenomenon of the battery during charge and discharge through the rate of electrochemical polarization accumulation, so as to accurately calculate the polarization voltage generated by the battery during charge and discharge.

[0014] In a possible implementation, the following method is used to determine the electrochemical polarization elimination voltage: based on the second mapping relationship, determine the second target polarization parameter that matches the rest time; the second mapping relationship includes second polarization parameters corresponding one-to-one to a plurality of rest times; the second polarization parameter is the polarization parameter measured during the electrochemical polarization elimination process of the battery; based on the rest time and the second target polarization parameter, determine the electrochemical polarization elimination voltage.

[0015] According to the above technical means, the present application can directly find the second target polarization parameter that matches it according to the rest time of the battery by establishing the second mapping relationship. This mapping relationship of measured data can reduce the error of the theoretical model or empirical formula and improve the accuracy of determining the electrochemical polarization elimination voltage.

[0016] In a possible implementation manner, the second polarization parameter includes: the rate of elimination of battery electrochemical polarization, and at least one of a time weight, a charge-discharge voltage correction coefficient, and a polarization voltage correction coefficient.

[0017] According to the above technical means, the present application can accurately reflect the fading speed of the polarization phenomenon of the battery during the standing process through the second polarization parameter including the rate of elimination of electrochemical polarization, so as to more accurately determine the electrochemical polarization elimination voltage. And by considering the influence of the standing time on polarization elimination through the time weight, it helps to more reasonably evaluate the elimination of the polarization voltage. In addition, the charge-discharge voltage correction coefficient and the polarization voltage correction coefficient consider the influence of voltage changes during the charge-discharge process on the polarization voltage, further improving the accuracy of polarization voltage determination.

[0018] In a possible implementation manner, the charge-discharge parameter includes the charge-discharge current of the target battery; determining the ohmic polarization voltage includes: determining the ohmic polarization voltage based on the charge-discharge current and the ohmic resistance of the target battery.

[0019] According to the above technical means, the present application can more accurately calculate the ohmic polarization voltage by directly considering the charge-discharge current and the ohmic resistance, avoiding the interference of other factors.

[0020] According to the second aspect provided by the present application, there is provided a polarization voltage determination device, including: an acquisition unit and a determination unit; the acquisition unit is configured to acquire battery parameters of a target battery; the battery parameters include charge-discharge parameters of the target battery in a charge-discharge state and a standing time in a standing state; the determination unit is configured to determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery based on the battery parameters; the determination unit is further configured to determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0021] In a possible implementation manner, the determination unit is specifically configured to: determine a first target polarization parameter matching the charge-discharge parameter based on a first mapping relationship; the first mapping relationship includes: a plurality of first polarization parameters corresponding one-to-one to a plurality of charge-discharge parameters; the first polarization parameter is a polarization parameter measured during the electrochemical polarization accumulation process of the battery; determine the electrochemical polarization accumulation voltage based on the charge-discharge parameter and the first target polarization parameter.

[0022] In a possible implementation manner, the determination unit is specifically configured to: determine a second target polarization parameter matching the standing time based on a second mapping relationship; the second mapping relationship includes second polarization parameters corresponding one-to-one to a plurality of standing times; the second polarization parameter is a polarization parameter measured during the electrochemical polarization elimination process of the battery; determine the electrochemical polarization elimination voltage based on the standing time and the second polarization parameter.

[0023] In a possible implementation manner, the determination unit is specifically configured to: determine the ohmic polarization voltage based on the charge and discharge current and the ohmic resistance of the target battery.

[0024] According to the third aspect provided by the present application, a vehicle is provided, and the vehicle includes the polarization voltage determination device in the second aspect.

[0025] According to the fourth aspect provided by the present application, an electronic device is provided, including: a processor; a memory for storing instructions executable by the processor; wherein, the processor is configured to execute the instructions to implement the method in the above-mentioned first aspect and any of its possible implementation manners.

[0026] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by the processor of the electronic device, the electronic device can execute the method in the above-mentioned first aspect and any of its possible implementation manners.

[0027] According to the sixth aspect provided by the present application, a computer program product is provided. The computer program product includes computer instructions. When the computer instructions run on the electronic device, the electronic device executes the method in the above-mentioned first aspect and any of its possible implementation manners.

[0028] It should be noted that for the technical effects brought by any implementation manner in the second aspect to the sixth aspect, reference can be made to the technical effects brought by the corresponding implementation manner in the first aspect, which will not be elaborated here.

[0029] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments in line with the present application, and are used together with the specification to explain the principles of the present application, and do not constitute an improper limitation to the present application.

[0031] Figure 1 is a schematic diagram of the hardware structure of a vehicle shown according to an exemplary embodiment;

[0032] Figure 2 is a flowchart of a polarization voltage determination method shown according to an exemplary embodiment;

[0033] Figure 3 is a schematic diagram of the polarization voltage under a charging condition shown according to an exemplary embodiment;

[0034] Figure 4 is a schematic diagram of a fitting result shown according to an exemplary embodiment;

[0035] Figure 5 It is a schematic diagram of another fitting result shown according to an exemplary embodiment;

[0036] Figure 6 It is a schematic diagram for comparing polarization voltages under a discharge condition shown according to an exemplary embodiment;

[0037] Figure 7 It is a schematic diagram of the result of comparing polarization voltages under a discharge condition shown according to an exemplary embodiment;

[0038] Figure 8 It is a schematic diagram for comparing polarization voltages under a charging condition shown according to an exemplary embodiment;

[0039] Figure 9 It is a schematic diagram of the result of comparing polarization voltages under a charging condition shown according to an exemplary embodiment;

[0040] Figure 10 It is a schematic diagram of a flow for determining polarization voltage shown according to an exemplary embodiment;

[0041] Figure 11 It is a block diagram of a device for determining polarization voltage shown according to an exemplary embodiment;

[0042] Figure 12 It is a block diagram of an electronic device shown according to an exemplary embodiment. Detailed implementation manners

[0043] In order to enable those of ordinary skill in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0045] First, some terms and related technologies involved in the present application are explained to facilitate the understanding of those skilled in the art.

[0046] The terminal voltage collected by the BMS includes the polarization voltage and the balance voltage.

[0047] Among them, the balance voltage, as a direct reflection of the thermodynamic properties of the electrode material, is the voltage value of the battery theoretically without external interference. The polarization voltage of a vehicle power battery refers to the potential difference generated by the polarization of the battery. The polarization will cause partial energy loss of the battery, which is usually divided into ohmic polarization and electrochemical polarization. The polarization voltage affects the terminal voltage of the battery, thus interfering with the accurate measurement and estimation of the SOC.

[0048] The accurate calculation of the polarization voltage helps the BMS to more accurately grasp the actual working state of the battery, so as to achieve accurate management of the battery. However, due to the polarization voltage being affected by various factors, it is difficult to calculate the polarization voltage of the battery.

[0049] In a related technology, a method for calculating the polarization voltage of a battery by multiplying the sum of the current and the increment of the internal resistance is proposed. However, the polarization voltage calculated by this method will increase linearly with time, which does not conform to the actual result.

[0050] In another related technology, a method based on looking up a table in a polarization voltage database is proposed to obtain the polarization voltage at the moment when the battery pack is powered off. This scheme first establishes a polarization voltage database and obtains the polarization voltage value at this moment by looking up the table. However, this method is too dependent on the offline calibrated database and the accuracy of the SOC.

[0051] As in the background technology, to solve the problem that it is difficult to accurately measure in the related technology, a method for determining the polarization voltage is provided, which can obtain the battery parameters of the target battery, and based on the battery parameters, determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery, so as to further determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage. Among them, the battery parameters include the charge and discharge parameters of the target battery in the charge and discharge state and the static time in the static state.

[0052] Based on this, this application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charge and discharge process, based on the battery parameters (including charge and discharge parameters and static time) of the target battery, so as to accurately determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery.

[0053] Next, the technical solutions in the embodiments of this application will be described with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments.

[0054] The polarization voltage determination method provided by the embodiments of the present application can be applied to vehicles. Vehicles can also be referred to as transportation means (vehicle), mobile carrier, electric vehicle (EV), hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), fuel cell vehicle (FCV), autonomous vehicle, intelligent and connected vehicle (ICV), driverless vehicle, etc.

[0055] In the embodiments of the present application, the vehicle can be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, a fire truck, a police car, etc.), a driverless taxi, an intelligent and connected bus, an autonomous logistics vehicle, an electric truck, etc. In addition, this method is also applicable to various special vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, port vehicles, etc. The present application does not make specific limitations in this regard.

[0056] Figure 1 Schematic diagram of the hardware structure of a vehicle shown according to an exemplary embodiment.

[0057] In a possible implementation manner, the vehicle 100 may include a polarization voltage determination device 101, a data acquisition device 102, and a target battery 103.

[0058] Optionally, Figure 1 A communication connection can be established between the polarization voltage determination device 101 and the data acquisition device 102 in. A connection can be established between the data acquisition device 102 and the target battery 103. A connection can be established between the polarization voltage determination device 101 and the target battery 103.

[0059] In practical applications, the polarization voltage determination device 101 can be communicatively connected to one or more data acquisition devices 102.

[0060] For ease of understanding, the present application takes the communication connection between one polarization voltage determination device 101 and one data acquisition device 102 as an example for illustration.

[0061] Optionally, Figure 1The polarization voltage determination device 101 and the data acquisition device 102 in it can be functional modules integrated in the same device or independent devices. This application does not limit this.

[0062] It is easy to understand that when the polarization voltage determination device 101 and the data acquisition device 102 are functional modules integrated in the same device, the communication method between the polarization voltage determination device 101 and the data acquisition device 102 is the communication between internal modules of the device. In this case, the communication process between the two is the same as the "communication process when the polarization voltage determination device 101 and the data acquisition device 102 are independently arranged".

[0063] For ease of understanding, this application mainly takes the case where the polarization voltage determination device 101 and the data acquisition device 102 are independently arranged as an example for illustration.

[0064] Figure 1 The data acquisition device 102 in it can acquire the battery parameters of the target battery 103. The polarization voltage determination device 101 can obtain the battery parameters acquired by the data acquisition device 102, and based on the battery parameters, determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery, and based on the electrochemical polarization voltage and the ohmic polarization voltage, determine the polarization voltage of the target battery.

[0065] Optionally, Figure 1 The polarization voltage determination device 101 in it can be a terminal, a server, or other types of electronic devices. Figure 1 What is shown in it is only an example of the device form of the polarization voltage determination device 101 and does not limit it.

[0066] When the polarization voltage determination device 101 is a terminal, the terminal can be a device that provides voice and / or data connectivity to the user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. The terminal can communicate with one or more core networks via a radio access network (RAN). The terminal can be a mobile terminal, such as a computer with a mobile terminal, or a mobile device built into the vehicle 100, which exchange language and / or data with the wireless access network. For example, mobile phones, tablets, laptops, netbooks, personal digital assistants (PDAs). This application does not limit this in any way.

[0067] When the polarization voltage determination device 101 is a server, the server can be a single server, or can be a server cluster composed of multiple servers. In some embodiments, the server cluster can also be a distributed cluster. The present application does not impose any restrictions on this.

[0068] It should be noted that the structure illustrated in the embodiments of the present application does not constitute a limitation on the vehicle 100. It may include more or fewer components than those illustrated, or combine certain components, or split certain components, or have different component arrangements. The illustrated components can be implemented in hardware, software, or a combination of software and hardware.

[0069] For ease of understanding, the polarization voltage determination method provided by the present application will be specifically introduced below with reference to the accompanying drawings.

[0070] Figure 2 is a flowchart of a polarization voltage determination method shown according to an exemplary embodiment, as Figure 2 shown, the polarization voltage determination method includes the following steps: S201 - S203.

[0071] S201. Obtain the battery parameters of the target battery.

[0072] Among them, the battery parameters may include the charge and discharge parameters of the target battery in the charge and discharge state and the rest time in the rest state. The rest state is the state where the current of the target battery is zero. The charge and discharge parameters of the target battery may include at least one of the charging current, charging voltage, battery temperature during charging, discharging current, discharging voltage, and battery temperature during discharging.

[0073] In a possible implementation manner, the polarization voltage determination device can measure and record data such as the voltage, current, and battery temperature of the target battery in the charge and discharge state as the charge and discharge parameters. The polarization voltage determination device can also detect and record the rest time of the target battery in the rest state. When the current of the target battery drops to zero, that is, when the target battery is in a non - working state, the polarization voltage determination device can start timing and accurately record the rest time of the battery.

[0074] Optionally, the polarization voltage determination device can obtain the battery parameters of the target battery periodically, or can obtain the battery parameters of the target battery at any time. The present application does not make specific restrictions on this.

[0075] S202. Based on the battery parameters, determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery.

[0076] Among them, the electrochemical polarization voltage includes: the electrochemical polarization accumulation voltage generated by the target battery in the charge and discharge state and the electrochemical polarization elimination voltage generated by the target battery in the rest state.

[0077] Exemplarily, as Figure 3 shown Figure 3 is a schematic diagram of the polarization voltage under a charging condition shown according to an exemplary embodiment.

[0078] When the time t is less than t1 seconds (s), the charging current is 0 amperes (A), and at this time, the target battery is in an equilibrium state, and the voltage is the equilibrium voltage. When the time t is at t1 s, the target battery starts constant current charging based on a current of 20 A. At this time, the ohmic polarization instantaneously responds, and the voltage suddenly changes to the ohmic polarization voltage. . When the time t is greater than t1 s and less than t2 s, the charge transfer polarization and mass transfer polarization of the target battery respond in sequence until the mass transfer polarization tends to be stable, that is, the target battery is in the process of electrochemical polarization accumulation (charge and discharge process). The electrochemical polarization accumulation voltage during the electrochemical polarization accumulation process from t1 s to t2 s is . When the time t is equal to t2 s, the constant current charging ends. At this time, the target battery is in a static state, and the polarization voltage generated when the target battery is in a static state is called the electrochemical polarization elimination voltage of the electrochemical polarization elimination process. .

[0079] Among them, charge transfer polarization refers to the polarization phenomenon generated during the operation of the battery because the charge transfer speed on the electrode cannot keep up with the current change speed. This is mainly due to the limitations in electrode reaction kinetics, resulting in the electrode potential deviating from the equilibrium potential. During the establishment of electrochemical polarization, the charge transfer polarization response time is about 1 ms, and the charge transfer polarization tends to be stable after 1 s. The mass transfer polarization response time is sub-second level, and the stable time of mass transfer polarization under constant current conditions is minute level.

[0080] Mass transfer polarization refers to the polarization phenomenon caused by the concentration change of reactants or products near the electrode. This is mainly due to the fact that the mass transfer speed cannot keep up with the electrode reaction speed.

[0081] In a possible implementation manner, the polarization voltage determination device can determine a first target polarization parameter matching the charge and discharge parameters based on the first mapping relationship. The polarization voltage determination device can determine the electrochemical polarization accumulation voltage based on the charge and discharge parameters and the first target polarization parameter. The specific implementation manner for the polarization voltage determination device to determine the electrochemical polarization accumulation voltage can refer to S301 - S302 below.

[0082] In yet another possible implementation, the polarization voltage determination device may determine a second target polarization parameter that matches the rest time based on the second mapping relationship. The polarization voltage determination device may determine the electrochemical polarization cancellation voltage based on the rest time and the first target polarization parameter. For the specific implementation of how the polarization voltage determination device determines the electrochemical polarization cancellation voltage, reference may be made to S401 - S402 below.

[0083] In a possible implementation, the polarization voltage determination device determines the ohmic polarization voltage based on the charge - discharge current and the ohmic resistance of the target battery.

[0084] Among them, the ohmic resistance can be used to characterize that the ohmic resistance is the resistance formed by the obstruction of the current due to the material itself and the contact part in the target battery. The ohmic resistance can reflect the magnitude of the resistance encountered when the current is transmitted inside the battery. The ohmic resistance can be obtained by methods such as ac impedance technology and direct measurement method with a multimeter.

[0085] It should be noted that when the target battery starts charging, the ohmic polarization will respond instantaneously. Therefore, it can be considered that the relationship between the ohmic polarization voltage and time can be ignored. The ohmic polarization voltage can satisfy the following first formula:

[0086]

[0087] Among them, can be used to characterize the ohmic polarization voltage of the target battery. can be used to characterize the ohmic resistance of the target battery. can be used to characterize the charge - discharge current of the target battery. The current is positive during charging and negative during discharging.

[0088] S203. Determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0089] In a possible implementation, the polarization voltage determination device may determine the sum of the electrochemical polarization voltage and the ohmic polarization voltage as the polarization voltage of the target battery.

[0090] Exemplarily, the polarization voltage of the target battery satisfies the following second formula:

[0091]

[0092] Among them, can be used to characterize the polarization voltage of the target battery. can be used to characterize the ohmic polarization voltage of the target battery. can be used to characterize the electrochemical polarization accumulation voltage. can be used to characterize the electrochemical polarization cancellation voltage.

[0093] In a possible implementation manner, the polarization voltage determination device may determine the SOC value of the target battery based on the polarization voltage of the target voltage.

[0094] Specifically, the polarization voltage determination device may determine the terminal voltage of the target battery. The polarization voltage determination device may determine the balance voltage of the target battery based on the polarization voltage and the terminal voltage of the target battery. The polarization voltage determination device may determine the SOC value of the target battery based on the balance voltage of the target battery. The following third formula is satisfied among the polarization voltage, the terminal voltage, and the balance voltage of the target battery:

[0095]

[0096] Wherein, can be used to characterize the terminal voltage. V0 can be used to characterize the balance voltage. can be used to characterize the polarization voltage.

[0097] Based on the above technical solution, the present application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charge and discharge process, based on the battery parameters of the target battery (including charge and discharge parameters and rest time), so as to accurately determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery.

[0098] In some embodiments, in order to determine the accumulated electrochemical polarization voltage of the target battery, the polarization voltage determination method provided by the present application further includes the following steps: S301 - S302.

[0099] S301. Determine a first target polarization parameter that matches the charge and discharge parameters based on the first mapping relationship.

[0100] Wherein, the first mapping relationship may include: a plurality of first polarization parameters corresponding one-to-one to a plurality of charge and discharge parameters. The first polarization parameter may be a polarization parameter measured during the electrochemical polarization accumulation process of the battery. The battery may be a battery of the same model as the target battery.

[0101] In a possible implementation manner, the first polarization parameter may include a polarization factor. The polarization factor may be used to characterize the rate of electrochemical polarization accumulation of the battery. In a possible implementation manner, the polarization voltage determination device may determine the first polarization parameter based on the following steps.

[0102] S3001. Establish an experimental test table.

[0103] As shown in Table 1, Table 1 shows the experimental test table.

[0104] Table 1

[0105]

[0106] Among them, T1, T2, T3, and T4 can be used to characterize the battery temperature. I1, I2, I3, and I4 can be used to characterize the current.

[0107] It should be noted that the parameters shown in Table 1 do not constitute a limitation on the parameters in the experimental test table. The experimental test table may include more or fewer parameters than those in Table 1. In the following steps S3002 - S3012, the steps reflected in Table 1 are combined. When Table 1 changes, the parameters involved in steps S3002 - S3012 should also correspond to Table 1.

[0108] S3002. Adjust the temperature to T1 and let it stand for 2 hours.

[0109] S3003. Discharge the target battery based on the first constant current until the voltage of the target battery reaches the cut-off voltage.

[0110] Optionally, the first constant current can be set according to actual needs. The first constant current can be 0.5 coulombs (C), or it can also be 1 C. This application does not make specific restrictions on this.

[0111] S3004. Charge the target battery with the first constant current until the SOC of the target battery reaches X1.

[0112] S3005. Let the target battery stand for the first preset duration.

[0113] Optionally, the first preset duration can be set according to actual needs. The first preset duration can be 2 hours, or it can also be 3 hours. This application does not make specific restrictions on this.

[0114] S3006. Charge the target battery with I1 in the experimental test table for the second preset duration.

[0115] Optionally, the second preset duration can be set according to actual needs. The second preset duration can be 5 minutes, or it can also be 10 minutes. This application does not make specific restrictions on this.

[0116] S3007. Let the target battery stand for the third preset duration.

[0117] Optionally, the third preset duration can be set according to actual needs. The third preset duration can be 1 hour, or it can also be 3 hours. This application does not make specific restrictions on this.

[0118] S3008. Charge the target battery with I1 in the experimental test table for the fourth preset duration.

[0119] Optionally, the fourth preset duration can be set according to actual needs. The fourth preset duration can be 5 minutes, or it can also be 10 minutes. This application does not make specific restrictions on this.

[0120] S3009. Let the target battery stand for the fifth preset duration.

[0121] Optionally, the fifth preset duration can be set according to actual requirements. The fifth preset duration can be 1 hour or 2 hours. This application does not make specific restrictions on this.

[0122] S3010. Adjust the current to I2, I3, I4 in the experimental test table, and repeat steps S3006 - S3009.

[0123] S3011. Repeat steps S3004 - S3010, with SOC replaced by x2, x3, x4, ……, 100%.

[0124] S3012. Set the ambient temperature to T2, T3, T4 in the experimental test table respectively, and repeat S3002 - S3012.

[0125] S3013. Based on the following fourth formula, fit the charge - discharge parameters and polarization voltage values obtained from the test to obtain the first polarization parameter corresponding to the charge - discharge parameters.

[0126]

[0127] Among them, can be used to characterize the accumulated voltage of electrochemical polarization. . can be used to characterize the polarization factor, that is, the first target polarization parameter. α and β can be used to characterize the transfer coefficient, and the transfer coefficient is the weight of charge - transfer polarization and mass - transfer polarization. can be used to characterize the base of the natural logarithm. I can be used to characterize the charge - discharge current, with the current being positive during charging and negative during discharging. R can be used to characterize the gas constant, and it can take the value of 8.314. T can be used to characterize the battery temperature.

[0128] Exemplarily, as Figure 4 shown, Figure 4 is a schematic diagram of a fitting result shown according to an exemplary embodiment. Figure 4 includes the measured polarization accumulation voltage curve and the fitted polarization accumulation voltage curve determined based on the fourth formula. Figure 4 In it, the horizontal axis is used to characterize time, with seconds (s) as the measurement unit. The vertical axis is used to characterize the polarization voltage, with volts (V) as the measurement unit.

[0129] Exemplarily, based on the fourth formula, fitting the charge - discharge parameters and polarization voltage values obtained from the test, the first polarization parameter corresponding to the charge - discharge parameters is = 0.0561, = 0.02367.

[0130] In a possible implementation manner, based on S3002 - S3013, the present application can determine the first polarization parameter of the target battery under multiple charge - discharge parameters.

[0131] Exemplarily, in combination with Table 1, as shown in Table 2, Table 2 shows the first polarization parameters corresponding to the multiple charge - discharge parameters in Table 1.

[0132] Table 2

[0133]

[0134] Exemplarily, in combination with Table 1, the first polarization parameter corresponding to the charge - discharge parameters T1 and I1 is Parameter 1, or the first polarization parameter corresponding to the charge - discharge parameters T2 and I1 is Parameter 2.

[0135] S302. Determine the electrochemical polarization accumulation voltage based on the charge - discharge parameters and the first target polarization parameter.

[0136] In a possible implementation manner, the charge - discharge parameters, the first target polarization parameter, and the electrochemical polarization accumulation voltage satisfy the fourth formula in S301.

[0137] Exemplarily, in combination with the example in S301, the first target polarization parameter is = 0.0561, = 0.02367. The charge - discharge parameters, the first target polarization parameter, and the electrochemical polarization accumulation voltage satisfy the following fifth formula:

[0138]

[0139] Based on this, the present application can establish the first mapping relationship in advance through the measured data, so as to directly find the first target polarization parameter matching the charge - discharge parameters according to the charge - discharge parameters, and further accurately calculate the electrochemical polarization accumulation voltage according to the first target polarization parameter and the charge - discharge parameters.

[0140] In some examples, in order to determine the electrochemical polarization elimination voltage, the polarization voltage determination method provided by the present application further includes the following steps: S401 - S402.

[0141] S401. Determine the second target polarization parameter matching the rest time based on the second mapping relationship.

[0142] Among them, the second mapping relationship may include the second polarization parameters corresponding one - to - one to multiple rest times. The second polarization parameter may be the polarization parameter measured during the electrochemical polarization elimination process of the battery.

[0143] In a possible implementation manner, the second polarization parameter may include: the rate of electrochemical polarization elimination, and at least one of a time weight, a charge-discharge voltage correction coefficient, and a polarization voltage correction coefficient.

[0144] S402. Determine the electrochemical polarization elimination voltage based on the rest time and the second target polarization parameter.

[0145] In a possible implementation manner, the following sixth formula is satisfied among the rest time, the second target polarization parameter, and the electrochemical polarization elimination voltage:

[0146]

[0147] Wherein, can be used to characterize the electrochemical polarization elimination voltage. can be used to characterize the depolarization factor, that is, the rate of battery electrochemical polarization elimination. can be used to characterize the voltage correction coefficient. can be used to characterize the rest time. can be used to characterize the time weight. can be used to characterize the polarization voltage correction coefficient.

[0148] In a possible implementation manner, the polarization voltage determination device may determine the measured polarization voltage value and the rest time based on the steps in S3001 - S3012. Thus, the polarization voltage determination device may fit the measured rest time and polarization voltage value based on the sixth formula to obtain the second polarization parameter corresponding to the charge-discharge parameter.

[0149] Exemplarily, as Figure 5 shown, Figure 5 is a schematic diagram of another fitting result shown according to an exemplary embodiment. Figure 5 includes the measured polarization elimination voltage curve and the fitted polarization elimination voltage curve determined based on the fourth formula. Figure 5 In it, the horizontal axis is used to characterize time, with seconds (s) as the measurement unit. The vertical axis is used to characterize the polarization voltage, with volts (V) as the measurement unit.

[0150] Exemplarily, based on the sixth formula, the measured rest time and polarization voltage value are fitted to obtain a second mapping relationship. The polarization voltage determination device may determine that the second target polarization parameter corresponding to the rest time is μ = -0.003403, ε = 1, θ = 0.03, δ = 0.8 based on the second mapping relationship. Based on this, the following seventh formula is satisfied among the rest time, the second target polarization parameter, and the electrochemical polarization elimination voltage:

[0151]

[0152] Among them, it can be used to characterize the electrochemical polarization elimination voltage. it can be used to characterize the rest time.

[0153] In a possible implementation manner, the polarization voltage determination device can determine the electrochemical polarization voltage based on the electrochemical polarization accumulation voltage and the electrochemical polarization elimination voltage.

[0154] Specifically, the polarization voltage determination device can determine the sum of the electrochemical polarization accumulation voltage and the electrochemical polarization elimination voltage as the electrochemical polarization voltage.

[0155] Based on this, by combining the first formula, the second formula, the fourth formula, and the sixth formula, the polarization voltage of the target battery can be determined to satisfy the following eighth formula:

[0156]

[0157] Among them, it can be used to characterize the polarization voltage of the target battery. it can be used to characterize the ohmic resistance of the target battery. it can be used to characterize the charge and discharge current of the target battery. The current is positive during charging and negative during discharging. , it can be used to characterize the first target polarization parameter, that is, the rate of electrochemical polarization accumulation of the battery. α and β can be used to characterize the transfer coefficient, and the transfer coefficient is the weight of charge transfer polarization and mass transfer polarization. it can be used to characterize the base of the natural logarithm. I can be used to characterize the charge and discharge current. The current is positive during charging and negative during discharging. R can be used to characterize the gas constant, and its value can be 8.314. T can be used to characterize the battery temperature. it can be used to characterize the depolarization factor, that is, the rate of electrochemical polarization elimination of the battery. it can be used to characterize the voltage correction coefficient. it can be used to characterize the rest time. it can be used to characterize the time weight. it can be used to characterize the polarization voltage correction coefficient.

[0158] By combining the first formula, the second formula, and the examples of the first target polarization parameter and the second target polarization parameter in the fifth formula and the seventh formula, the polarization voltage of the target battery can be determined to satisfy the following ninth formula:

[0159]

[0160] Based on this, the present application can establish a second mapping relationship and directly find the second target polarization parameter that matches the standing time of the battery. This mapping relationship of measured data can reduce the error of the theoretical model or empirical formula and improve the accuracy of determining the electrochemical polarization elimination voltage.

[0161] In some embodiments, as Figure 6 shown, Figure 6 is a schematic diagram comparing polarization voltages under a discharge condition shown according to an exemplary embodiment.

[0162] It should be noted that Figure 6 includes the first calculated polarization voltage curve under the discharge condition of the target battery and the first measured polarization voltage curve under the discharge condition of the target battery. Figure 6 In the horizontal axis is used to represent time, with seconds (s) as the measurement unit. The vertical axis is used to represent the polarization voltage, with volts (V) as the measurement unit.

[0163] Among them, the first calculated polarization voltage curve is a curve formed by the polarization voltage determined based on the polarization voltage determination method provided by the present application under the discharge condition of the target battery. The first measured polarization voltage curve can be a curve formed by the polarization voltage determined based on a calibrated method under the discharge condition of the target battery. The present application does not make specific limitations on this.

[0164] Optionally, the target battery can be set according to actual needs. For example, the target battery can be a lithium iron phosphate (LEP) battery or a ternary lithium battery. The present application does not make specific limitations on this.

[0165] Exemplarily, in combination with Figure 6 , as Figure 7 shown, Figure 7 is a schematic diagram showing the comparison result of polarization voltages under a discharge condition shown according to an exemplary embodiment.

[0166] Figure 7 shows Figure 6 the comparison result between the first calculated polarization voltage curve and the first measured polarization voltage curve in Figure 7 In the horizontal axis is used to represent time, with seconds (s) as the measurement unit. The vertical axis is used to represent the error, with volts (V) as the measurement unit. Based on Figure 7 it can be known that at the same discharge duration, the maximum error of the polarization voltage between the first calculated polarization voltage curve and the first measured polarization voltage curve is about 0.01V, that is, 10mV. For example, when the discharge duration is about 16s, the error of the polarization voltage between the first calculated polarization voltage curve and the first measured polarization voltage curve is about 10mV.

[0167] In some embodiments, such as Figure 8 shown, Figure 8 is a schematic diagram of the comparison of polarization voltages under a charging condition shown according to an exemplary embodiment. Figure 8 The horizontal axis therein is used to represent time, with seconds (s) used as the measurement unit. The vertical axis is used to represent the polarization voltage, with volts (V) used as the measurement unit.

[0168] It should be noted that Figure 8 includes the second calculated polarization voltage curve under the charging condition of the target battery and the second measured polarization voltage curve under the charging condition of the target battery.

[0169] Among them, the second calculated polarization voltage curve is a curve formed by the polarization voltage determined based on the polarization voltage determination method provided in the present application under the charging condition of the target battery. The second measured polarization voltage curve can be a curve formed by the polarization voltage determined based on a calibrated method under the charging condition of the target battery. The present application does not make specific limitations on this.

[0170] Exemplarily, in combination with Figure 8 , such as Figure 9 shown, Figure 9 is a schematic diagram of the comparison result of polarization voltages under a charging condition shown according to an exemplary embodiment. Figure 9 The horizontal axis therein is used to represent time, with seconds (s) used as the measurement unit. The vertical axis is used to represent the error, with volts (V) used as the measurement unit.

[0171] Figure 9 shows Figure 8 the comparison result between the second calculated polarization voltage curve and the second measured polarization voltage curve in Figure 9 . It can be known from

[0172] that when the battery capacity is relatively low, the error of the polarization voltage between the second calculated polarization voltage curve and the second measured polarization voltage curve is about 0.03 V, and when the battery capacity is relatively high, the error of the polarization voltage between the second calculated polarization voltage curve and the second measured polarization voltage curve is within 0.02 V. Figure 10 shown, Figure 10 is a schematic diagram of a polarization voltage determination process shown according to an exemplary embodiment.

[0173] In a possible implementation manner, the polarization voltage determination device can obtain the ohmic polarization voltage caused by the ohmic resistance. The polarization voltage determination device can obtain the electrochemical polarization accumulation voltage. The polarization voltage determination device can obtain the electrochemical polarization elimination voltage. The polarization voltage determination device can determine the polarization voltage of the battery based on the ohmic polarization voltage, the electrochemical polarization accumulation voltage, and the electrochemical polarization elimination voltage.

[0174] Figure 11 is a block diagram of a polarization voltage determination device shown according to an exemplary embodiment. Refer to Figure 11 , the polarization voltage determination device includes: an acquisition unit 501 and a determination unit 502.

[0175] In a possible implementation manner, the acquisition unit 501 is configured to acquire battery parameters of a target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a stationary time in a stationary state.

[0176] In a possible implementation manner, the determination unit 502 is configured to determine an electrochemical polarization voltage and an ohmic polarization voltage of the target battery based on the battery parameters.

[0177] In a possible implementation manner, the determination unit 502 is further configured to determine a polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0178] In a possible implementation manner, the determination unit 502 is specifically configured to: determine a first target polarization parameter matching the charge and discharge parameters based on a first mapping relationship. Determine an electrochemical polarization accumulation voltage based on the charge and discharge parameters and the first target polarization parameter.

[0179] In a possible implementation manner, the determination unit 502 is specifically configured to: determine a second target polarization parameter matching the stationary time based on a second mapping relationship; the second mapping relationship includes second polarization parameters corresponding one by one to a plurality of stationary times. Determine an electrochemical polarization elimination voltage based on the stationary time and the second polarization parameter.

[0180] In a possible implementation manner, the determination unit 502 is specifically configured to: determine an ohmic polarization voltage based on the charge and discharge current and the ohmic resistance of the target battery.

[0181] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0182] Figure 12 is a block diagram of an electronic device shown according to an exemplary embodiment. As Figure 12 shown, the electronic device includes but is not limited to: a processor 601 and a memory 602.

[0183] Among them, the above-mentioned memory 602 is used to store executable instructions of the above-mentioned processor 601. It can be understood that the above-mentioned processor 601 is configured to execute instructions to implement the polarization voltage determination method in the above embodiments.

[0184] It should be noted that those skilled in the art can understand, Figure 12The structure of the electronic device shown does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than Figure 12 shown, or combine certain components, or have a different component arrangement.

[0185] The processor 601 is the control center of the electronic device, connecting various parts of the entire electronic device using various interfaces and lines. By running or executing software programs and / or modules stored in the memory 602, and by invoking the data stored in the memory 602, it performs various functions of the electronic device and processes data, thereby monitoring the electronic device as a whole. The processor 601 may include one or more processing units. Optionally, the processor 601 may integrate an application processor and a modem processor. Among them, the application processor mainly processes the operating system, user interface, application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor may not be integrated into the processor 601.

[0186] The memory 602 can be used to store software programs and various data. The memory 602 mainly includes a program storage area and a data storage area. Among them, the program storage area can store the operating system, application programs required by at least one functional module (such as a determination unit, a processing unit, etc.). In addition, the memory 602 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0187] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided. For example, the memory 602 including instructions, and the above instructions can be executed by the processor 601 of the electronic device to implement the method in the above embodiment.

[0188] In actual implementation, Figure 11 the functions of the acquisition unit 501 and the determination unit 502 in Figure 12 can both be implemented by the processor 601 in

[0189] invoking the computer program stored in the memory 602. The specific execution process can refer to the description of the method part in the above embodiment, and will not be elaborated here.

[0190] In an exemplary embodiment, the embodiment of the present application further provides a computer program product including one or more instructions, and the one or more instructions can be executed by a processor 601 of an electronic device to implement the method in the above embodiment.

[0191] It should be noted that when the instructions in the above computer-readable storage medium or the one or more instructions in the computer program product are executed by the processor of the electronic device, each process of the above method embodiment is implemented, and the same technical effect as the above method can be achieved. To avoid repetition, it will not be elaborated here.

[0192] Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to 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.

[0193] In several embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0194] The unit described as a separated component may or may not be physically separated, and the component displayed as a unit may be a physical unit or multiple physical units, that is, it may be located in one place, or may be distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0195] In addition, each functional unit in the various embodiments of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0196] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions for causing a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods of the embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0197] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. 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

1. A method for determining a polarization voltage, characterized in that The method includes: Obtaining battery parameters of a target battery; the battery parameters include charge-discharge parameters of the target battery in a charge-discharge state and a standing time in a standing state; Based on the battery parameters, determining an electrochemical polarization voltage and an ohmic polarization voltage of the target battery; the electrochemical polarization voltage includes: an electrochemical polarization accumulation voltage generated by the target battery in a charge-discharge state and an electrochemical polarization elimination voltage generated by the target battery in a standing state; the electrochemical polarization accumulation voltage is determined based on the charge-discharge parameters and the first target polarization parameter; the first target polarization parameter is matched from a first mapping relationship based on the charge-discharge parameters; the first target polarization parameter is matched from the first mapping relationship based on the charge-discharge parameters; Based on the electrochemical polarization voltage and the ohmic polarization voltage, determining the polarization voltage of the target battery.

2. The method according to claim 1, wherein The first polarization parameter includes a rate of electrochemical polarization accumulation of the battery.

3. The method according to claim 1, wherein The electrochemical polarization elimination voltage is determined in the following manner: Based on a second mapping relationship, determining a second target polarization parameter matched with the standing time; the second mapping relationship includes second polarization parameters corresponding one by one to a plurality of standing times; the second polarization parameter is a polarization parameter measured during the electrochemical polarization elimination process of the battery; Based on the standing time and the second target polarization parameter, determining the electrochemical polarization elimination voltage.

4. The method according to claim 3, wherein The second polarization parameter includes: a rate of electrochemical polarization elimination of the battery, and at least one of a time weight, a charge-discharge voltage correction coefficient, and a polarization voltage correction coefficient.

5. The method according to claim 1, wherein The charge-discharge parameters include a charge-discharge current of the target battery; determining the ohmic polarization voltage includes: Based on the charge-discharge current and an ohmic resistance of the target battery, determining the ohmic polarization voltage.

6. A polarization voltage determination device, characterized in that The device includes: an acquisition unit and a determination unit; The acquisition unit is configured to obtain battery parameters of a target battery; the battery parameters include charge-discharge parameters of the target battery in a charge-discharge state and a standing time in a standing state; The determination unit is configured to, based on the battery parameters, determine an electrochemical polarization voltage and an ohmic polarization voltage of the target battery; the electrochemical polarization voltage includes: an electrochemical polarization accumulation voltage generated by the target battery in a charge-discharge state and an electrochemical polarization elimination voltage generated by the target battery in a standing state; the electrochemical polarization accumulation voltage is determined based on the charge-discharge parameters and the first target polarization parameter; the first target polarization parameter is matched from a first mapping relationship based on the charge-discharge parameters; the first target polarization parameter is matched from the first mapping relationship based on the charge-discharge parameters; The determination unit is further configured to, based on the electrochemical polarization voltage and the ohmic polarization voltage, determine the polarization voltage of the target battery.

7. The device according to claim 6, characterized in that, The determination unit is specifically configured to: Determine a second target polarization parameter matching the standing time based on the second mapping relationship; the second mapping relationship includes second polarization parameters corresponding one by one to multiple standing times; the second polarization parameter is a polarization parameter measured during the electrochemical polarization elimination process of the battery; Determine the electrochemical polarization elimination voltage based on the standing time and the second polarization parameter.

8. A vehicle, characterized in that, The vehicle includes the device according to claim 6 or 7.

9. An electronic device, characterized in that, Comprising: A processor; A memory for storing executable instructions of the processor; Wherein, the processor is configured to execute the instructions to implement the method according to any one of claims 1-5.

Images