Method and apparatus for determining state of charge of battery, device, medium and product

Abstract

The present application discloses a method and apparatus for determining a state of charge of a battery, a device, a medium, and a product. The method comprises: acquiring a first state parameter and a first correspondence relationship of a sodium-ion battery, the first state parameter being the ratio of a battery energy change amount to an open circuit voltage change amount in a unit time, the first correspondence relationship is a correspondence relationship between a state of charge of the sodium-ion battery and a state parameter, and the state parameter being the ratio of the battery energy change amount to the open circuit voltage change amount in unit time; on the basis of the first correspondence relationship and the first state parameter, determining the state of charge of the sodium-ion battery. In this way, the state of charge of a sodium-ion battery can be determined more accurately.

Description

Method, device, equipment, medium and product for determining battery state of charge

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311119848.1, filed on August 31, 2023, entitled “Method, device, equipment, medium and product for determining battery state of charge,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a method, device, equipment, medium and product for determining a battery state of charge. Background Art

[0004] With the continuous development of battery technology, users have higher and higher requirements for the accuracy of evaluating battery state of charge.

[0005] However, the currently commonly used methods for evaluating the state of charge of lithium-ion batteries are not suitable for evaluating the state of charge of sodium-ion batteries.

[0006] Therefore, a method that can accurately assess the state of charge of sodium-ion batteries is needed.

[0007] Summary of the Invention

[0008] The present application provides a method, apparatus, device, medium and product for determining the state of charge of a battery, which can more accurately determine the state of charge of a sodium ion battery.

[0009] In a first aspect, the present application provides a method for determining a battery state of charge, comprising: obtaining a first state parameter and a first corresponding relationship of a sodium ion battery, where the first state parameter is the ratio of a battery energy change to an open circuit voltage change per unit time, and the first corresponding relationship is a corresponding relationship between the state of charge of the sodium ion battery and the state parameter, where the state parameter is the ratio of a battery energy change to an open circuit voltage change per unit time; and determining the state of charge of the sodium ion battery based on the first corresponding relationship and the first state parameter.

[0010] Since the degree of material phase change of the sodium ion battery will affect the SOC of the sodium ion battery during the charging and discharging process, the embodiment of the present application can reflect the degree of material phase change of the sodium ion battery through the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery, and then obtain the state of charge of the battery. Therefore, the state of charge of the sodium ion battery determined in the embodiment of the present application will be more accurate.

[0011] In some embodiments, determining the state of charge of the sodium ion battery according to the first correspondence and the first state parameter includes: obtaining a first open-circuit voltage of the sodium ion battery and a second correspondence, where the second correspondence is a correspondence between the state of charge and the open-circuit voltage of the sodium ion battery; determining a first state of charge corresponding to the first state parameter according to the first correspondence, and determining a second state of charge corresponding to the first open-circuit voltage according to the second correspondence; and performing weighted summation of the first state of charge and the second state of charge according to preset weights corresponding to the first state of charge and the second state of charge, to obtain the state of charge of the sodium ion battery.

[0012] In this way, through the above process, the state of charge of the sodium ion battery can be comprehensively determined based on the first corresponding relationship and the second corresponding relationship, so the state of charge of the sodium ion battery can be determined more accurately.

[0013] In some embodiments, obtaining a first state parameter and a first corresponding relationship of a sodium ion battery includes: obtaining a first open-circuit voltage and a second corresponding relationship of the sodium ion battery, where the second corresponding relationship is a corresponding relationship between the state of charge of the sodium ion battery and the open-circuit voltage; determining a second state of charge corresponding to the first open-circuit voltage based on the second corresponding relationship; and obtaining the first state parameter and the first corresponding relationship of the sodium ion battery when the second state of charge is greater than a state of charge threshold.

[0014] In this way, the second state of charge of the sodium ion battery can be determined based on the second corresponding relationship. If the second state of charge is greater than the state of charge threshold, the first state parameter of the sodium ion battery is calculated, without having to calculate the first state parameter each time, thereby reducing the amount of calculation and saving computing resources and time.

[0015] In some embodiments, the method further includes: when the second state of charge is less than or equal to a state of charge threshold, determining that the second state of charge is a state of charge of a sodium ion battery.

[0016] In this way, if the second state of charge determined based on the second corresponding relationship is less than or equal to the state of charge threshold, the second state of charge can be determined as the state of charge of the sodium ion battery, without the need to calculate the first state parameter and determine the state of charge based on the second corresponding relationship, thereby determining the state of charge of the sodium ion battery more quickly and accurately.

[0017] In some embodiments, before obtaining the first open circuit voltage and the second correspondence of the sodium ion battery, the method further includes: obtaining multiple third states of charge of the sodium ion battery during charging and / or discharging and their corresponding second open circuit voltages; fitting the multiple third states of charge and their corresponding second open circuit voltages to obtain a second correspondence.

[0018] In this way, by performing calibration through the above process, the second corresponding relationship of the sodium ion battery can be determined more accurately.

[0019] In some embodiments, before obtaining the first state parameter and the first corresponding relationship of the sodium ion battery, the method further includes: obtaining a fourth state of charge, a third open circuit voltage, and a first battery energy at multiple first moments, and a fourth open circuit voltage and a second battery energy at multiple second moments during the charging and / or discharging process of the sodium ion battery, where the second moment is before the first moment and is separated from the first moment by a unit time; calculating a first battery energy change corresponding to each fourth state of charge based on the first battery energy and the second battery energy corresponding to each fourth state of charge, and calculating a first open circuit voltage change corresponding to each fourth state of charge based on the third open circuit voltage and the fourth open circuit voltage corresponding to each fourth state of charge; calculating a ratio of the first battery energy change to the first open circuit voltage change corresponding to each fourth state of charge; and fitting the multiple fourth states of charge and their corresponding ratios to obtain the first corresponding relationship.

[0020] In this way, by performing calibration through the above process, the first corresponding relationship of the sodium ion battery can be determined more accurately.

[0021] In some embodiments, obtaining a first state parameter of a sodium ion battery includes: obtaining a third battery energy and a first open-circuit voltage of the sodium ion battery at a third moment, and a fourth battery energy and a fifth open-circuit voltage of the sodium ion battery at a fourth moment, where the fourth moment is before the third moment and is separated from the third moment by a unit time; calculating a second battery energy change of the sodium ion battery based on the third battery energy and the fourth battery energy, and calculating a second open-circuit voltage change of the sodium ion battery based on the first open-circuit voltage and the fifth open-circuit voltage; and calculating a ratio of the second battery energy change to the second open-circuit voltage change to obtain the first state parameter.

[0022] In this way, the first state parameter of the sodium ion battery can be automatically and accurately determined through the above process, so as to subsequently accurately determine the state of charge of the sodium ion battery.

[0023] In a second aspect, the present application provides a device for determining a battery state of charge, comprising: a first acquisition module, configured to acquire a first state parameter and a first corresponding relationship of a sodium ion battery, the first state parameter being the ratio of a battery energy change to an open-circuit voltage change per unit time; the first corresponding relationship being a corresponding relationship between the state of charge of the sodium ion battery and the state parameter, the state parameter being the ratio of a battery energy change to an open-circuit voltage change per unit time; and a determination module, configured to determine the state of charge of the sodium ion battery based on the first corresponding relationship and the first state parameter.

[0024] Since the degree of material phase change of the sodium ion battery will affect the SOC of the sodium ion battery during the charging and discharging process, the embodiment of the present application can reflect the degree of material phase change of the sodium ion battery through the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery, and then obtain the state of charge of the battery. Therefore, the state of charge of the sodium ion battery determined in the embodiment of the present application will be more accurate.

[0025] In a third aspect, the present application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions;

[0026] When the processor executes the computer program instructions, the method for determining the battery state of charge as shown in any one of the embodiments of the first aspect is implemented.

[0027] In a fourth aspect, the present application provides a computer storage medium having computer program instructions stored thereon, which, when executed by a processor, implements the method for determining the battery state of charge shown in any one of the embodiments of the first aspect.

[0028] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for determining the battery charge state shown in any one of the embodiments of the first aspect.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0031] FIG1 is a flow chart of a method for determining a battery state of charge according to some embodiments of the present application;

[0032] FIG2 is a schematic diagram of a corresponding relationship curve between a fourth state of charge and a third open-circuit voltage provided by some embodiments of the present application;

[0033] FIG3 is a schematic diagram of a curve showing a corresponding relationship between state of charge and state parameters provided by some embodiments of the present application;

[0034] FIG4 is a schematic diagram of a corresponding relationship curve between a third state of charge and a second open circuit voltage provided by some embodiments of the present application;

[0035] FIG5 is a second flow chart of a method for determining a battery state of charge according to some embodiments of the present application;

[0036] FIG6 is a schematic structural diagram of a vehicle control system provided by some embodiments of the present application;

[0037] FIG7 is a schematic structural diagram of a device for determining a battery state of charge according to some embodiments of the present application;

[0038] FIG8 is a schematic structural diagram of an electronic device provided in some embodiments of the present application. DETAILED DESCRIPTION

[0039] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0041] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0042] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0044] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0045] State of Charge (SOC) refers to the ratio of available power in a battery to its nominal capacity. It is a key monitoring metric for the battery management system, which controls the battery's operating status based on SOC. The battery's SOC reflects the remaining charge in the battery.

[0046] In related technologies, during the charging process of a secondary battery, there is a corresponding relationship between the SOC and the open circuit voltage (OCV). Based on this relationship, the estimated SOC of the secondary battery during the charging or discharging process can be calculated. Secondary batteries, also known as rechargeable batteries or storage batteries, can refer to batteries that can be recharged after discharge to activate the active materials and continue to be used. OCV can be the terminal voltage of the battery in the open circuit state.

[0047] During the charge and discharge process of sodium-ion batteries, the battery materials will undergo phase changes. Phase change refers to the process in which a substance changes from one phase to another. The degree of phase change of the sodium-ion battery material will affect the SOC of the sodium-ion battery. For example, under different SOC conditions, the negative electrode material has corresponding ways of absorbing and desorbing sodium ions during the charge and discharge process, which makes the sodium ion absorption and desorption rate and the OCV of the sodium-ion battery different. For example, during the charging process, as the SOC increases, the way the negative electrode of the sodium-ion battery absorbs sodium ions may change, the sodium ion absorption rate decreases, and the OVC decreases. During the discharge process, as the SOC decreases, the sodium ion desorption rate may decrease and the OCV increases. Therefore, using a single OCV as the input for monitoring SOC may increase the error of the estimated SOC.

[0048] In some embodiments of the present application, the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery can be used to reflect the degree of material phase change of the sodium ion battery, thereby obtaining the SOC. The battery energy change can be the change in battery energy per unit time, and the battery energy can refer to the total amount of electrical energy that the battery can provide. The unit of battery energy can be watt-hour (Wh) or joule (J).

[0049] First, the method for determining the battery state of charge provided in an embodiment of the present application is described in detail with reference to FIG1 .

[0050] FIG1 shows a flow chart of a method for determining a battery state of charge provided by an embodiment of the present application. It should be noted that the method for determining a battery state of charge can be applied to a device for determining a battery state of charge.

[0051] As shown in FIG1 , the method for determining the battery state of charge may include the following steps:

[0052] S110, obtaining a first state parameter and a first corresponding relationship of the sodium ion battery;

[0053] S120: Determine the state of charge of the sodium ion battery according to the first corresponding relationship and the first state parameter.

[0054] Since the degree of material phase change of the sodium ion battery will affect the SOC of the sodium ion battery during the charging and discharging process, the embodiment of the present application can reflect the degree of material phase change of the sodium ion battery through the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery, and then obtain the state of charge of the battery. Therefore, the state of charge of the sodium ion battery determined in the embodiment of the present application will be more accurate.

[0055] Regarding S110, the first corresponding relationship may be a corresponding relationship between the state of charge of the sodium ion battery and a state parameter. The state parameter may be a ratio of a battery energy change to an open circuit voltage change per unit time.

[0056] Here, the first state parameter may be a current state parameter of the sodium ion battery. The first corresponding relationship may be pre-calibrated.

[0057] The first state parameter may be a ratio of a change in battery energy to a change in open circuit voltage per unit time.

[0058] Battery energy can be measured by a charger and discharger, or by integrating the open circuit voltage and current of the sodium ion battery.

[0059] In some embodiments, obtaining battery energy of a sodium ion battery may include:

[0060] Obtain the open circuit voltage, current, and charge and discharge status of sodium ion batteries;

[0061] When the charge and discharge state of the sodium ion battery is a charging state, obtaining a charging time of the sodium ion battery;

[0062] Calculate the product of open circuit voltage, current and charging time to obtain the battery energy of the sodium ion battery;

[0063] When the charge and discharge state of the sodium ion battery is a discharge state, obtaining a discharge time of the sodium ion battery;

[0064] Calculate the product of open circuit voltage, current and discharge time to obtain the discharge energy of the sodium ion battery;

[0065] The difference between the nominal capacity and discharge energy of the sodium ion battery is calculated to obtain the battery energy of the sodium ion battery.

[0066] Here, discharge energy can be the battery energy released by the sodium ion battery during the discharge time. The nominal capacity can be the battery energy that the battery can provide under certain discharge conditions after being fully charged.

[0067] Specifically, the open-circuit voltage U of the sodium-ion battery can be collected by a voltage sensor, and the current I of the sodium-ion battery can be measured by a current transformer. If the sodium-ion battery is in a charging state, the charging time t1 of the sodium-ion battery can be obtained, and then the battery energy Q=UIt1 of the sodium-ion battery is calculated; if the sodium-ion battery is in a discharging state, the discharge time t2 of the sodium-ion battery can be obtained, and then the battery energy Q=C-UIt2 of the sodium-ion battery is calculated, where C is the nominal capacity of the sodium-ion battery.

[0068] In this way, the battery energy of the sodium ion battery can be obtained by integrating the open circuit voltage and current.

[0069] In S120 , a first state of charge corresponding to the current first state parameter of the sodium ion battery may be searched from the first corresponding relationship, and the first state of charge may be determined as the state of charge of the sodium ion battery.

[0070] In some embodiments, to more accurately determine the state of charge of the sodium ion battery, S120 may include:

[0071] Obtaining a first open circuit voltage and a second corresponding relationship of the sodium ion battery;

[0072] Determine a first state of charge corresponding to the first state parameter according to the first corresponding relationship, and determine a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship;

[0073] The first state of charge and the second state of charge are weighted and summed according to preset weights corresponding to the first state of charge and the second state of charge, so as to obtain the state of charge of the sodium ion battery.

[0074] Here, the first open circuit voltage may be the current open circuit voltage of the sodium ion battery.

[0075] The second corresponding relationship may be a corresponding relationship between the state of charge and the open circuit voltage of the sodium ion battery. For example, the second corresponding relationship may be a SOC-OCV curve.

[0076] The preset weights can be set according to actual needs.

[0077] In this way, through the above process, the state of charge of the sodium ion battery can be comprehensively determined based on the first corresponding relationship and the second corresponding relationship, so the state of charge of the sodium ion battery can be determined more accurately.

[0078] In some embodiments, in order to obtain an accurate first correspondence, before S110, the method may further include:

[0079] Obtaining a fourth state of charge, a third open circuit voltage, and a first battery energy at a plurality of first moments, and a fourth open circuit voltage and a second battery energy at a plurality of second moments during a charging and / or discharging process of the sodium ion battery;

[0080] calculating a change in the first battery energy corresponding to each fourth state of charge based on the first battery energy and the second battery energy corresponding to each fourth state of charge, and calculating a change in the first open circuit voltage corresponding to each fourth state of charge based on the third open circuit voltage and the fourth open circuit voltage corresponding to each fourth state of charge;

[0081] Calculating a ratio of a first battery energy change to a first open circuit voltage change corresponding to each fourth state of charge;

[0082] A plurality of fourth states of charge and their corresponding ratios are fitted to obtain a first corresponding relationship.

[0083] Here, the first corresponding relationship can be fitted based on the data of the sodium ion battery during the charging process, the first corresponding relationship can be fitted based on the data of the sodium ion battery during the discharging process, or the first corresponding relationship can be fitted based on the data of the sodium ion battery during the charging and discharging processes, and the first corresponding relationship is not limited here.

[0084] Fitting involves connecting a series of points on a plane with a smooth curve. The fitted curve can generally be represented by a function. Therefore, the first correspondence can be either a curve or a function.

[0085] Illustratively, at least one of the fitting methods including but not limited to linear, polynomial, logarithmic, exponential, etc. can be used to fit multiple fourth states of charge and their corresponding ratios to obtain the first corresponding relationship.

[0086] For example, the sodium ion battery can be charged at a constant current of 0.02C in a constant temperature environment of 25°C, and the SOC of the sodium ion battery can be charged from 0% to 100%. The battery is then left to stand for 6 hours, and then the sodium ion battery is discharged at a constant current of 0.02C, and the SOC of the sodium ion battery is discharged from 100% to 0%. During the charging and discharging process, the fourth state of charge, the third open circuit voltage, and the first battery energy of the sodium ion battery at multiple first moments, as well as the fourth open circuit voltage and the second battery energy at multiple second moments are obtained. For example, as shown in FIG2 , the corresponding relationship curve of the fourth state of charge and the third open circuit voltage during the charging process can be a first curve 210, and the corresponding relationship curve of the fourth state of charge and the third open circuit voltage during the discharging process can be a second curve 220.

[0087] Charging and discharging at a current of 0.02C can depolarize the battery, making the obtained open circuit voltage and battery energy data more accurate. Of course, charging and discharging at other current values ​​can also be performed, and this is not limited here.

[0088] Here, C can refer to the rate, and 0.02C current can mean the current is 0.02 times the battery capacity. For example, if the battery capacity is 1 ampere-hour, 0.02C current can be 0.02 times 1, or 0.02A; if the battery capacity is 10 ampere-hours, 0.02C current can be 0.02 times 10, or 0.2A.

[0089] The plurality of first moments may be any plurality of moments during the charging and / or discharging process of the sodium ion battery. The second moment may be before the first moment and separated from the first moment by a unit time. For example, the unit time may be 1 second.

[0090] Specifically, the fourth state of charge, third open circuit voltage, and first battery energy of the sodium ion battery at time t, as well as the fourth open circuit voltage and second battery energy at time t-1, can be obtained during the charging process. The difference between the first battery energy and the second battery energy corresponding to the fourth state of charge is calculated to obtain the first battery energy change corresponding to the fourth state of charge. The difference between the third open circuit voltage and the fourth open circuit voltage corresponding to the fourth state of charge is calculated to obtain the first open circuit voltage change corresponding to the fourth state of charge. Then, the ratio of the first battery energy change corresponding to the fourth state of charge to the first open circuit voltage change is calculated. In this way, a fourth state of charge and its corresponding ratio can be obtained. Based on the above method, the fourth state of charge and its corresponding ratio at multiple moments can be obtained. By fitting the multiple fourth states of charge and their corresponding ratios, a first corresponding relationship can be obtained.

[0091] For example, the first corresponding relationship may be as shown in FIG3 Curve, where dQ is the battery energy change per unit time, dV is the open circuit voltage change per unit time, and the state parameter can be

[0092] In this way, by performing calibration through the above process, the first corresponding relationship of the sodium ion battery can be determined more accurately.

[0093] In some embodiments, in order to obtain a more accurate first state parameter, obtaining the first state parameter of the sodium ion battery may include:

[0094] Obtaining a third battery energy and a first open-circuit voltage of the sodium ion battery at a third moment, and a fourth battery energy and a fifth open-circuit voltage of the sodium ion battery at a fourth moment;

[0095] Calculating a second battery energy change of the sodium ion battery based on the third battery energy and the fourth battery energy, and calculating a second open circuit voltage change of the sodium ion battery based on the first open circuit voltage and the fifth open circuit voltage;

[0096] The ratio of the second battery energy change to the second open circuit voltage change is calculated to obtain a first state parameter.

[0097] Here, the fourth moment may be before the third moment and separated from the third moment by a unit time. The third moment may be the current moment.

[0098] Specifically, the third battery energy and the first open circuit voltage of the sodium ion battery at the T moment, as well as the fourth battery energy and the fifth open circuit voltage of the sodium ion battery at the T-1 moment can be obtained, and the difference between the third battery energy and the fourth battery energy is calculated to obtain the second battery energy change, and the difference between the first open circuit voltage and the fifth open circuit voltage is calculated to obtain the second open circuit voltage change, and then the ratio of the second battery energy change to the second open circuit voltage change is calculated to obtain the first state parameter.

[0099] In this way, the first state parameter of the sodium ion battery can be automatically and accurately determined through the above process, so as to subsequently accurately determine the state of charge of the sodium ion battery.

[0100] In some embodiments, to quickly determine the state of charge of the sodium ion battery, S110 may include:

[0101] Obtaining a first open circuit voltage and a second corresponding relationship of the sodium ion battery;

[0102] determining a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship;

[0103] When the second state of charge is greater than the state of charge threshold, a first state parameter and a first corresponding relationship of the sodium ion battery are obtained.

[0104] Here, the first open circuit voltage may be the current open circuit voltage of the sodium ion battery.

[0105] The second corresponding relationship may be a corresponding relationship between the state of charge and the open circuit voltage of the sodium ion battery. For example, the second corresponding relationship may be a SOC-OCV curve.

[0106] The state of charge threshold can be set according to actual conditions.

[0107] When the state of charge of the sodium ion battery is greater than the state of charge threshold, the correspondence between the state of charge and the open circuit voltage during the charging process of the sodium ion battery and the correspondence between the state of charge and the open circuit voltage during the discharge process are less consistent. Based on the correspondence between the state of charge and the open circuit voltage, the accuracy of determining the state of charge of the sodium ion battery by the open circuit voltage is low.

[0108] Therefore, the second state of charge of the sodium ion battery can be determined by the first open circuit voltage based on the correspondence between the state of charge and the open circuit voltage of the sodium ion battery, that is, the second correspondence. If the second state of charge is greater than the state of charge threshold, the first state parameter and the first correspondence of the sodium ion battery are obtained. Based on the first correspondence, the state of charge of the sodium ion battery is determined by the first state parameter.

[0109] Exemplarily, the state of charge threshold may be 40%.

[0110] In this way, the second state of charge of the sodium ion battery can be determined based on the second corresponding relationship. If the second state of charge is greater than the state of charge threshold, the first state parameter of the sodium ion battery is calculated, without having to calculate the first state parameter each time, thereby reducing the amount of calculation and saving computing resources and time.

[0111] In some embodiments, in order to quickly determine the state of charge of the sodium ion battery, the method may further include:

[0112] When the second state of charge is less than or equal to the state of charge threshold, the second state of charge is determined to be the state of charge of a sodium ion battery.

[0113] Here, when the state of charge of the sodium ion battery is less than or equal to the state of charge threshold, the correspondence between the state of charge and the open circuit voltage during the charging process of the sodium ion battery and the correspondence between the state of charge and the open circuit voltage during the discharging process are more consistent with each other. Therefore, the state of charge of the sodium ion battery can be determined based on the correspondence between the state of charge and the open circuit voltage, that is, the second correspondence.

[0114] In this way, if the second state of charge determined based on the second corresponding relationship is less than or equal to the state of charge threshold, the second state of charge can be determined as the state of charge of the sodium ion battery, without the need to calculate the first state parameter and determine the state of charge based on the second corresponding relationship, thereby determining the state of charge of the sodium ion battery more quickly and accurately.

[0115] In some embodiments, in order to obtain an accurate second correspondence, before obtaining the first open-circuit voltage and the second correspondence of the sodium ion battery, the method may further include:

[0116] Obtaining a plurality of third states of charge and corresponding second open circuit voltages of the sodium ion battery during a charging and / or discharging process;

[0117] A second corresponding relationship is obtained by fitting the plurality of third states of charge and their corresponding second open circuit voltages.

[0118] Here, the second corresponding relationship can be fitted based on the data of the sodium ion battery during the charging process, the second corresponding relationship can be fitted based on the data of the sodium ion battery during the discharging process, or the second corresponding relationship can be fitted based on the data of the sodium ion battery during the charging and discharging processes, without limitation here.

[0119] For example, the sodium ion battery can be discharged at a current of 0.33C under a constant temperature environment of 25°C. After each discharge of 0.05C capacity, the battery is allowed to rest for 6 hours. After repeating this 20 times, the SOC of the sodium ion battery can be discharged from 100% to 0%. The sodium ion battery can then be charged at a current of 0.33C. After each charge of 0.05C capacity, the battery is allowed to rest for 6 hours. After repeating this 20 times, the SOC of the sodium ion battery can be charged from 0% to 100%. During this charging and discharging process, the third state of charge and the second open-circuit voltage of the sodium ion battery can be obtained after each rest. For example, as shown in FIG4 , the corresponding relationship curve of the third state of charge and the second open-circuit voltage during the discharge process can be a third curve 410, and the corresponding relationship curve of the third state of charge and the second open-circuit voltage during the charging process can be a fourth curve 420.

[0120] 6 hours of standing still can depolarize the device, making the acquired open circuit voltage and other data more accurate. Of course, other standing time periods are also possible and are not limited here.

[0121] In this way, by performing calibration through the above process, the second corresponding relationship of the sodium ion battery can be determined more accurately.

[0122] In addition, after determining the state of charge of the sodium ion battery, the sodium ion battery can be discharged to a state of charge of 0% using a charger and discharger, and the discharge capacity recorded by the charger and discharger is compared with the state of charge of the sodium ion battery calculated by the above method to determine the deviation of the calculated state of charge. When the deviation is greater than 5%, corresponding measures can be taken to make adjustments so that the deviation is less than or equal to 5%.

[0123] To better describe the entire solution, based on the above embodiments, a specific example is given, as shown in FIG5 , where the method for determining the battery state of charge may include S501 to S506 .

[0124] S501, obtaining a first open circuit voltage and a second corresponding relationship of a sodium ion battery.

[0125] S502 : Determine a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship.

[0126] S503: Determine whether the second state of charge is greater than a state of charge threshold.

[0127] If yes, execute S504; if no, execute S506.

[0128] S504: Obtain a first state parameter and a first corresponding relationship of the sodium ion battery.

[0129] S505 : Determine, according to the first corresponding relationship, that a first state of charge corresponding to the first state parameter is a state of charge of a sodium ion battery.

[0130] S506: Determine that the second state of charge is a state of charge of a sodium ion battery.

[0131] The specific process and meaning of each step can be found in the above embodiments and will not be described in detail here.

[0132] Since the degree of material phase change of the sodium ion battery will affect the SOC of the sodium ion battery during the charging and discharging process, the embodiment of the present application can reflect the degree of material phase change of the sodium ion battery through the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery, and then obtain the state of charge of the battery. Therefore, the state of charge of the sodium ion battery determined in the embodiment of the present application will be more accurate.

[0133] The battery state-of-charge determination method provided in the embodiments of the present application can be used to determine the state of charge of a vehicle's battery. Based on this, the embodiments of the present application also provide a vehicle control system, which can be used to execute the battery state-of-charge determination method provided in the embodiments of the present application. The vehicle control system provided in the embodiments of the present application is described in detail below with reference to FIG6 .

[0134] FIG6 shows a schematic structural diagram of a vehicle control system provided by an embodiment of the present application.

[0135] As shown in FIG6 , the vehicle control system may include: an open circuit voltage acquisition module 610 , a battery energy acquisition module 620 , a data processing module 630 and a logic calculation unit 640 .

[0136] The open circuit voltage acquisition module 610 may be used to acquire the open circuit voltage signal waveform of the sodium ion battery.

[0137] The battery energy acquisition module 620 can be used to acquire the battery energy signal waveform of the sodium ion battery.

[0138] The data processing module 630 can be used to convert the open circuit voltage signal waveform of the sodium ion battery into an open circuit voltage value (including the various open circuit voltages involved in the above embodiments), and convert the battery energy signal waveform of the sodium ion battery into a battery energy value (including the various battery energies involved in the above embodiments).

[0139] The logic calculation unit 640 can be used to calculate the state of charge of the sodium ion battery based on the open circuit voltage value and the battery energy value. The specific calculation method can be found in the above embodiment and will not be repeated here.

[0140] Based on the same inventive concept, the embodiment of the present application further provides a device for determining the battery state of charge. The device for determining the battery state of charge provided by the embodiment of the present application is described in detail below with reference to FIG7 .

[0141] FIG7 shows a schematic structural diagram of a device for determining a battery state of charge provided by an embodiment of the present application.

[0142] As shown in FIG7 , the device for determining the battery state of charge may include:

[0143] A first acquisition module 701 is configured to acquire a first state parameter and a first corresponding relationship of the sodium ion battery, where the first state parameter is a ratio of a battery energy change to an open circuit voltage change per unit time, and the first corresponding relationship is a corresponding relationship between the state of charge of the sodium ion battery and the state parameter, where the state parameter is a ratio of a battery energy change to an open circuit voltage change per unit time;

[0144] The determination module 702 is configured to determine the state of charge of the sodium ion battery according to the first corresponding relationship and the first state parameter.

[0145] Since the degree of material phase change of the sodium ion battery will affect the SOC of the sodium ion battery during the charging and discharging process, the embodiment of the present application can reflect the degree of material phase change of the sodium ion battery through the ratio of the battery energy change to the open circuit voltage change per unit time of the sodium ion battery, and then obtain the state of charge of the battery. Therefore, the state of charge of the sodium ion battery determined in the embodiment of the present application will be more accurate.

[0146] In some embodiments, to more accurately determine the state of charge of the sodium ion battery, the determination module 702 may include:

[0147] A first acquisition submodule is used to obtain a first open circuit voltage and a second corresponding relationship of the sodium ion battery, where the second corresponding relationship is a corresponding relationship between the state of charge of the sodium ion battery and the open circuit voltage;

[0148] a first determining submodule, configured to determine a first state of charge corresponding to the first state parameter according to the first corresponding relationship, and to determine a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship;

[0149] The first calculation submodule is configured to perform weighted summation on the first state of charge and the second state of charge according to preset weights corresponding to the first state of charge and the second state of charge, so as to obtain the state of charge of the sodium ion battery.

[0150] In some embodiments, in order to quickly determine the state of charge of the sodium ion battery, the first acquisition module 701 may include:

[0151] A second acquisition submodule is used to obtain a first open circuit voltage and a second corresponding relationship of the sodium ion battery, where the second corresponding relationship is a corresponding relationship between the state of charge of the sodium ion battery and the open circuit voltage;

[0152] a second determining submodule, configured to determine a second state of charge corresponding to the first open circuit voltage according to a second corresponding relationship;

[0153] The third acquisition submodule is configured to acquire, when the second state of charge is greater than a state of charge threshold, a first state parameter and a first corresponding relationship of the sodium ion battery.

[0154] In some embodiments, in order to quickly determine the state of charge of the sodium ion battery, the apparatus may further include:

[0155] The third determining submodule is configured to determine that the second state of charge is a state of charge of a sodium ion battery when the second state of charge is less than or equal to a state of charge threshold.

[0156] In some embodiments, in order to obtain an accurate second correspondence, the apparatus may further include:

[0157] A second acquisition module is configured to acquire, before acquiring the first open circuit voltage and the second corresponding relationship of the sodium ion battery, a plurality of third states of charge of the sodium ion battery during a charging and / or discharging process and their corresponding second open circuit voltages;

[0158] The first fitting module is used to fit a plurality of third states of charge and their corresponding second open circuit voltages to obtain a second corresponding relationship.

[0159] In some embodiments, in order to obtain an accurate first correspondence, the apparatus may further include:

[0160] a third acquisition module, configured to, before acquiring the first state parameter and the first corresponding relationship of the sodium ion battery, acquire, during a charging and / or discharging process, a fourth state of charge, a third open circuit voltage, and a first battery energy at a plurality of first moments, and the fourth open circuit voltage and the second battery energy at a plurality of second moments, where the second moments are before the first moment and are separated from the first moment by a unit time;

[0161] a first calculation module, configured to calculate a change in the first battery energy corresponding to each fourth state of charge based on the first battery energy and the second battery energy corresponding to each fourth state of charge, and calculate a change in the first open circuit voltage corresponding to each fourth state of charge based on the third open circuit voltage and the fourth open circuit voltage corresponding to each fourth state of charge;

[0162] a second calculation module, configured to calculate a ratio of a first battery energy change to a first open circuit voltage change corresponding to each fourth state of charge;

[0163] The second fitting module is used to fit multiple fourth states of charge and their corresponding ratios to obtain a first corresponding relationship.

[0164] In some embodiments, in order to obtain a more accurate first state parameter, the first acquisition module 701 may include:

[0165] a fourth acquisition submodule, configured to acquire a third battery energy and a first open-circuit voltage of the sodium ion battery at a third moment, and a fourth battery energy and a fifth open-circuit voltage of the sodium ion battery at a fourth moment, where the fourth moment is before the third moment and is separated from the third moment by a unit time;

[0166] A second calculation submodule is used to calculate a second battery energy change of the sodium ion battery based on the third battery energy and the fourth battery energy, and to calculate a second open circuit voltage change of the sodium ion battery based on the first open circuit voltage and the fifth open circuit voltage;

[0167] The third calculation submodule is used to calculate the ratio of the second battery energy change to the second open circuit voltage change to obtain the first state parameter.

[0168] FIG8 shows a schematic structural diagram of an electronic device provided by an embodiment of the present application.

[0169] As shown in Figure 8, the electronic device 8 is a block diagram of an exemplary hardware architecture of an electronic device capable of implementing the method and apparatus for determining the battery state of charge in the embodiments of the present application. The electronic device may refer to the electronic device in the embodiments of the present application.

[0170] The electronic device 8 may include a processor 801 and a memory 802 storing computer program instructions.

[0171] Specifically, the processor 801 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0172] Memory 802 may include a large-capacity memory for data or instructions. By way of example and not limitation, memory 802 may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 802 may include removable or non-removable (or fixed) media. Where appropriate, memory 802 may be internal or external to the integrated gateway disaster recovery device. In certain embodiments, memory 802 is non-volatile solid-state memory. In certain embodiments, memory 802 may include read-only memory (ROM), random access memory (RAM), a magnetic disk storage media device, an optical storage media device, a flash memory device, an electrical, optical, or other physical / tangible memory storage device. Thus, generally, memory 802 includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of the present application.

[0173] The processor 801 reads and executes computer program instructions stored in the memory 802 to implement any one of the battery state of charge determination methods in the above embodiments.

[0174] In one example, the electronic device may further include a communication interface 803 and a bus 804. As shown in FIG8, the processor 801, the memory 802, and the communication interface 803 are connected via the bus 804 and communicate with each other.

[0175] The communication interface 803 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0176] Bus 804 comprises hardware, software or both, couples the parts of electronic equipment to each other.For example, and not limitation, bus can comprise accelerated graphics port (AGP) or other graphics bus, enhanced industry standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industry standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations.In suitable cases, bus 804 can comprise one or more buses.Although the present application embodiment describes and shows specific bus, the application considers any suitable bus or interconnection.

[0177] The electronic device can execute the method for determining the battery state of charge in the embodiment of the present application, thereby realizing the method and device for determining the battery state of charge described in conjunction with Figures 1 to 7.

[0178] In addition, in conjunction with the battery state of charge determination method in the above-mentioned embodiments, embodiments of the present application may provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any of the battery state of charge determination methods in the above-mentioned embodiments is implemented.

[0179] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0180] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0181] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0182] Aspects of the present application have been described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed via the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. This processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It is also understood that each box in the block diagram and / or the flowchart and the combination of the boxes in the block diagram and / or the flowchart can also be implemented by the dedicated hardware that performs the specified function or action, or can be implemented by the combination of dedicated hardware and computer instructions.

[0183] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A method for determining a battery state of charge, comprising: Acquire a first state parameter and a first corresponding relationship of a sodium ion battery, wherein the first state parameter is a ratio of a battery energy change to an open circuit voltage change within a unit time, and the first corresponding relationship is a corresponding relationship between a state of charge of the sodium ion battery and a state parameter, and the state parameter is a ratio of a battery energy change to an open circuit voltage change within a unit time; The state of charge of the sodium ion battery is determined according to the first corresponding relationship and the first state parameter.

2. The method according to claim 1, wherein: Determining the state of charge of the sodium ion battery according to the first corresponding relationship and the first state parameter includes: Acquire a first open circuit voltage and a second corresponding relationship of the sodium ion battery, wherein the second corresponding relationship is a corresponding relationship between a state of charge of the sodium ion battery and the open circuit voltage; Determine a first state of charge corresponding to the first state parameter according to the first corresponding relationship, and determine a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship; According to preset weights corresponding to the first state of charge and the second state of charge respectively, the first state of charge and the second state of charge are weightedly summed to obtain the state of charge of the sodium ion battery.

3. The method according to claim 1 or 2, wherein: The obtaining of the first state parameter and the first corresponding relationship of the sodium ion battery includes: Acquire a first open circuit voltage and a second corresponding relationship of the sodium ion battery, wherein the second corresponding relationship is a corresponding relationship between a state of charge of the sodium ion battery and the open circuit voltage; determining a second state of charge corresponding to the first open circuit voltage according to the second corresponding relationship; When the second state of charge is greater than a state of charge threshold, a first state parameter and a first corresponding relationship of the sodium ion battery are obtained.

4. The method according to claim 3, further comprising: When the second state of charge is less than or equal to the state of charge threshold, the second state of charge is determined to be the state of charge of the sodium ion battery.

5. According to the method of any one of claims 2 to 4, before obtaining the first open circuit voltage and the second corresponding relationship of the sodium ion battery, the method further comprises: Acquire a plurality of third states of charge and their corresponding second open circuit voltages of the sodium ion battery during charging and / or discharging; The second corresponding relationship is obtained by fitting a plurality of the third states of charge and their respectively corresponding second open circuit voltages.

6. According to the method according to any one of claims 1 to 5, before obtaining the first state parameter and the first corresponding relationship of the sodium ion battery, the method further comprises: Acquire a fourth state of charge, a third open circuit voltage, and a first battery energy at a plurality of first moments, and a fourth open circuit voltage and a second battery energy at a plurality of second moments during the charging and / or discharging process of the sodium ion battery, wherein the second moment is before the first moment and is separated from the first moment by a unit time; Calculate the first battery energy change corresponding to each of the fourth states of charge based on the first battery energy and the second battery energy corresponding to each of the fourth states of charge, and calculate the first open circuit voltage change corresponding to each of the fourth states of charge based on the third open circuit voltage and the fourth open circuit voltage corresponding to each of the fourth states of charge; Calculating a ratio of the first battery energy change to the first open circuit voltage change corresponding to each of the fourth state of charge; Fitting is performed on a plurality of the fourth states of charge and the ratios respectively corresponding thereto to obtain the first corresponding relationship.

7. The method according to any one of claims 1 to 6, wherein: The obtaining of a first state parameter of the sodium ion battery comprises: Acquire a third battery energy and a first open-circuit voltage of the sodium ion battery at a third moment, and a fourth battery energy and a fifth open-circuit voltage of the sodium ion battery at a fourth moment, wherein the fourth moment is before the third moment and is separated from the third moment by a unit time; Based on the third battery energy and the fourth battery energy, calculating a second battery energy change of the sodium ion battery, and based on the first open circuit voltage and the fifth open circuit voltage, calculating a second open circuit voltage change of the sodium ion battery; The ratio of the second battery energy change to the second open circuit voltage change is calculated to obtain the first state parameter.

8. A device for determining a battery state of charge, the device comprising: A first acquisition module is used to acquire a first state parameter and a first corresponding relationship of a sodium ion battery, wherein the first state parameter is a ratio of a battery energy change to an open circuit voltage change within a unit time, and the first corresponding relationship is a corresponding relationship between a state of charge of the sodium ion battery and a state parameter, and the state parameter is a ratio of a battery energy change to an open circuit voltage change within a unit time; A determination module is used to determine the state of charge of the sodium ion battery according to the first corresponding relationship and the first state parameter.

9. An electronic device, comprising: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the method for determining the battery state of charge as described in any one of claims 1 to 7 is implemented.

10. A computer storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the method for determining the battery state of charge according to any one of claims 1 to 7.

11. A computer program product, wherein when instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for determining the battery state of charge according to any one of claims 1 to 7.

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