Patent Application
20240044995
The present disclosure relates to a battery management apparatus and method, and more particularly, to a battery management apparatus and method capable of diagnosing a state of a battery in a non-destructive manner.
Recently, the demand for portable electronic products such as notebook computers, video cameras and portable telephones has increased sharply, and electric vehicles, energy storage batteries, robots, satellites and the like have been developed in earnest. Accordingly, high-performance batteries allowing repeated charging and discharging are being actively studied.
Batteries commercially available at present include nickel-cadmium batteries, nickel hydrogen batteries, nickel-zinc batteries, lithium batteries and the like. Among them, the lithium batteries are in the limelight since they have almost no memory effect compared to nickel-based batteries and also have very low self-charging rate and high energy density.
The battery may degrade as charging and discharging continue. For example, the state of the battery may be classified into BOL (Beginning of life), MOL (Middle of life) and EOL (End of life) according to the degree of degradation, and among them, the EOL battery may be treated as unusable.
Conventionally, the state of health (SOH) of the battery is estimated based on the change in capacity or internal resistance of the battery, or the state of the battery is diagnosed through VOLCANO analysis (a method of analyzing a differential profile (V-dQdV profile or Q-dVdQ profile)).
In particular, when the state of the battery is the EOL state, it is preferable that the corresponding battery be treated as unusable. However, if there is an error in diagnosing the state of the battery or the state of the battery is not quickly diagnosed, the battery in the EOL state may be used, which may cause an unexpected accident.
The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery management apparatus and method capable of diagnosing a state of a battery in a non-destructive manner through differential profile analysis.
These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof.
A battery management apparatus according to one aspect of the present disclosure may comprise: a processor, and memory having programmed thereon instructions that, when executed, are configured to cause the processor to generate a differential profile for a battery profile representing a corresponding relationship between voltage and capacity of a battery; determine a criterion peak and a target peak in the differential profile, and diagnose a state of the battery based on a result of comparing a differential value of the criterion peak and a differential value of the target peak.
The instructions are configured to cause the processor to generate at least one of (i) a differential voltage profile representing a corresponding relationship between the capacity and a differential voltage for the capacity and (ii) a differential capacity profile representing a corresponding relationship between the voltage and a differential capacity for the voltage, as the differential profile.
The instructions are configured to cause the processor to determine a type of the differential profile, and determine the criterion peak and the target peak in the differential profile according to a rule preset to correspond to the determined type of the differential profile.
When the differential voltage profile is received, the instructions are configured to cause the processor to classify the differential voltage profile into a criterion region and a target region according to the capacity, determine a first peak with a smallest differential voltage in the criterion region as the criterion peak, and determine a second peak with a smallest differential voltage in the target region as the target peak.
When a differential voltage value of the criterion peak is less than a differential voltage value of the target peak, the instructions are configured to cause the processor to diagnose the state of the battery as an unusable state.
When the differential voltage value of the criterion peak is equal to or greater than the differential voltage value of the target peak, the instructions are configured to cause the processor to diagnose the state of the battery as a usable state.
When the differential capacity profile is received, the instructions are configured to cause the processor to classify the differential capacity profile into a criterion region and a target region according to the voltage, determine a first peak with a first greatest differential capacity in the criterion region as the criterion peak, and determine a second peak with a second greatest differential capacity in the target region as the target peak.
When a differential capacity value of the criterion peak exceeds a differential capacity value of the target peak, the instructions are configured to cause the processor to diagnose the state of the battery as an unusable state.
When the differential capacity value of the criterion peak is equal to or less than the differential capacity value of the target peak, the instructions are configured to cause the processor to diagnose the state of the battery as a usable state.
The target peak may be configured to appear in a differential profile for a high nickel-based battery containing a predetermined amount of nickel or more.
A battery pack according to another aspect of the present disclosure may comprise the battery management apparatus according to an aspect of the present disclosure.
A battery management method according to still another aspect of the present disclosure may comprise: generating, by one or more processors, a differential profile for a battery profile representing a corresponding relationship between voltage and capacity of a battery; determining, by the one or more processors, a criterion peak and a target peak in the differential profile generated in the differential profile generating step; and diagnosing, by the one ore more processors, a state of the battery based on a result of comparing a differential value of the criterion peak and a differential value of the target peak.
According to one aspect of the present disclosure, the state of the battery may be diagnosed in a non-destructive manner through differential profile analysis. In particular, whether the state of the battery is an unusable state may be specifically diagnosed.
The effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.
The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawing.
It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.
Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.
Additionally, in describing the present disclosure, when it is deemed that a detailed description of relevant known elements or functions renders the key subject matter of the present disclosure ambiguous, the detailed description is omitted herein.
The terms including the ordinal number such as “first”, “second” and the like, may be used to distinguish one element from another among various elements, but not intended to limit the elements by the terms.
Throughout the specification, when a portion is referred to as “comprising” or “including” any element, it means that the portion may include other elements further, without excluding other elements, unless specifically stated otherwise.
In addition, throughout the specification, when a portion is referred to as being “connected” to another portion, it is not limited to the case that they are “directly connected”, but it also includes the case where they are “indirectly connected” with another element being interposed between them.
Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
Referring to
The profile generating unit 110 may be configured to generate a differential profile for a battery profile representing a corresponding relationship between voltage and capacity of a battery.
Here, the battery means one physically separable independent cell including a negative electrode terminal and a positive electrode terminal. For example, one lithium-ion battery or lithium polymer battery may be regarded as a battery. Also, the battery may refer to a battery module in which a plurality of cells are connected in series and/or in parallel. Hereinafter, for convenience of explanation, the battery will be described as meaning one independent cell.
Specifically, the profile generating unit 110 may directly receive the battery profile from the outside or may directly generate the battery profile by periodically receiving the voltage and capacity of the battery from the outside.
For example, the battery profile may represent a corresponding relationship between the capacity (Q) and voltage (V) of the battery. Here, the unit of capacity may be [mAh], and the unit of voltage may be [V]. In addition, the battery profile may be expressed as an X-Y two-dimensional graph, when X is set as capacity and Y is set as voltage.
In addition, the profile generating unit 110 may generate a differential profile corresponding to the first derivative of the battery profile. For example, the profile generating unit 110 may generate a differential capacity profile representing a corresponding relationship between the voltage (V) and the differential capacity (dQ/dV) and/or a differential voltage profile representing a corresponding relationship between the capacity (Q) and the differential voltage (dV/dQ).
The control unit 120 may be configured to determine a criterion peak and a target peak in the differential profile received from the profile generating unit 110.
Specifically, the control unit 120 may classify the region of the differential profile into a criterion region RR and a target region TR that do not overlap each other. In addition, the control unit 120 may determine the criterion peak in the criterion region RR and determine the target peak in the target region TR.
The control unit 120 may be configured to diagnose the state of the battery based on a result of comparing a differential value of the criterion peak and a differential value of the target peak.
For example, the control unit 120 may compare the magnitudes of the differential value of the criterion peak and the differential value of the target peak, and diagnose the state of the battery as an unusable state or a usable state according to the comparison result. Here, the unusable state may mean a state in which the state of the battery is an EOL state, and thus the battery cannot be used. The usable state may mean a state in which the state of the battery is a BOL or MOL state, and thus the battery can be used.
In general, a battery in the EOL state is a battery that has undergone a considerable amount of degradation, and may mean a battery having an SOH of 70% or less. The battery in the EOL state is in a state in which positive electrode capacity and/or usable lithium is lost, and in some cases, lithium plating (Li-plating) from which metallic lithium is deposited may occur on the surface of the negative electrode. Therefore, if the battery in the EOL state is continuously used, unexpected accidents such as explosion and/or fire may occur due to an internal short circuit.
The control unit 120 may diagnose the state of the battery by determining both the differential value of the criterion peak that can serve as the criterion value and the differential value of the target peak that that can serve as the comparison value in consideration of one differential profile for the battery.
That is, the battery management apparatus 100 may determine the state of the battery by comparing the differential values of two peaks that can be determined from the differential profile, without comparing the differential value of a peak determined from the differential profile with a specific value that is preset uniformly. Accordingly, the battery management apparatus 100 has an advantage of more accurately diagnosing the current state of the battery by adopting a diagnosing method that can reflect the current state of the battery in a best way.
Meanwhile, the profile generating unit 110 and the control unit 120 provided in the battery management apparatus 100 may selectively include processors known in the art, application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, and the like to execute various control logic performed in the present disclosure. Also, when the control logic is implemented in software, the profile generating unit 110 and the control unit 120 may be implemented as a set of program modules. At this time, the program module may be stored in a memory and executed by the profile generating unit 110 and the control unit 120. The memory may be located inside or out of each of the profile generating unit 110 and the control unit 120 and may be connected to the profile generating unit 110 and the control unit 120 by various well-known means.
In addition, the battery management apparatus 100 may further include a storage unit 130. The storage unit 130 may store data necessary for operation and function of each component of the battery management apparatus 100, data generated in the process of performing the operation or function, or the like. The storage unit 130 is not particularly limited in its type as long as it is a known information storage means that can record, erase, update and read data. As an example, the information storage means may include random access memory (RAM), flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), registers, and the like. In addition, the storage unit 130 may store program codes in which processes executable by the control unit 120 are defined.
Preferably, the target peak may be configured to appear in a differential profile for a high nickel-based battery containing a certain amount of nickel or more.
In general, the high nickel-based battery may mean a battery in which the content of nickel contained in the positive electrode material is 80% or more. Conversely, a low nickel-based battery may mean a battery in which the content of nickel contained in the positive electrode material is less than 80%. For example, an NCM battery having a ratio of nickel (N), cobalt (C) and manganese (M) of 8:1:1 or 9: ½: ½ may be the high nickel-based battery.
In addition, the target peak determined by the control unit 120 may be a peak appearing in the high nickel-based battery.
In general, phase equilibrium may occur during battery charging. In addition, when phase equilibrium occurs, the peak of the differential profile of the battery may appear. For example, when four phase equilibrium occurs, Ec (1), Ec (2), Ec (3) and Ec (4) peaks may be sequentially included in the differential profile. In addition, in order to generate the fourth phase equilibrium corresponding to the Ec (4) peak, the content of nickel included in the positive electrode material of the battery may be 80% or more. For example, the Ec (2) peak corresponding to the second phase equilibrium may correspond to the criterion peak, and the Ec (4) peak corresponding to the fourth phase equilibrium may correspond to the target peak.
On the other hand, if the content of nickel included in the positive electrode material is less than 80%, the fourth phase equilibrium may not occur, and even if the fourth phase equilibrium occurs, a corresponding target peak may not be generated.
Therefore, since the battery management apparatus 100 according to an embodiment of the present disclosure uses a battery in which the content of nickel contained in the positive electrode material is 80% or more, it is possible to clearly determine the target peak in the differential profile. Accordingly, the battery management apparatus 100 may more specifically diagnose the state of the battery.
The profile generating unit 110 may be configured to generate at least one of a differential voltage profile representing a corresponding relationship between the capacity and a differential voltage for the capacity and a differential capacity profile representing a corresponding relationship between the voltage and a differential capacity for the voltage, as the differential profile.
Referring to
Referring to
The control unit 120 may be configured to determine the type of the differential profile received from the profile generating unit 110.
For example, when receiving the differential profile from the profile generating unit 110, the control unit 120 may receive information on the type of the differential profile together. Accordingly, the control unit 120 may clearly classify the type of the differential profile generated by the profile generating unit 110 as a differential capacity profile or a differential voltage profile.
As another example, the profile generating unit 110 may be preconfigured to generate one type of differential profile. In addition, the profile generating unit 110 may be configured to generate a different type of differential profile when there is a request from the control unit 120. Accordingly, the control unit 120 may clearly classify the type of the differential profile received from the profile generating unit 110.
The control unit 120 may be configured to determine the criterion peak and the target peak in the received differential profile according to a rule preset to correspond to the determined type of the differential profile.
Specifically, the control unit 120 may determine the criterion peak and the target peak in the differential capacity profile and the differential voltage profile in different ways. Since the differential capacity profile and the differential voltage profile are differential profiles representing a corresponding relationship between different factors, the control unit 120 may determine the criterion peak and the target peak according to a rule corresponding to the type of the differential profile, respectively.
When the control unit 120 receives the differential voltage profile from the profile generating unit 110, the control unit 120 may be configured to classify the differential voltage profile into a criterion region RR and a target region TR according to capacity. For example, the control unit 120 may half the capacity region of the differential voltage profile and classify a low capacity region as the criterion region RR and a high capacity region as the target region TR.
In the embodiment of
In addition, the control unit 120 may be configured to determine a peak with the smallest differential voltage in the criterion region RR as the criterion peak, and determine a peak with the smallest differential voltage in the target region TR as the target peak.
For example, in the embodiment of
When the differential voltage value of the criterion peak is less than the differential voltage value of the target peak, the control unit 120 may diagnose the state of the battery as an unusable state. Conversely, when the differential voltage value of the criterion peak is equal to or greater than the differential voltage value of the target peak, the control unit 120 may diagnose the state of the battery as a usable state.
In general, in the differential voltage profile, as the battery degrades, the capacity value corresponding to the target peak is shifted to the low capacity side, and the differential voltage value corresponding to the target peak may be increased. That is, in the embodiment of
In the embodiment of
Preferably, the control unit 120 may be configured to block charging and discharging of the second battery so that the second battery diagnosed as an unusable state is not used. For example, the control unit 120 may block charging and discharging of the second battery by controlling the relay connected to the positive electrode terminal and/or the negative electrode terminal of the second battery to a turn-off state. As another example, in order to indicate that the second battery is in an unusable state, the control unit 120 may label the state of the battery as an unusable state in the battery information about the second battery.
When receiving the differential capacity profile from the profile generating unit 110, the control unit 120 may be configured to classify the differential capacity profile into a criterion region RR and a target region TR according to voltage. For example, the control unit 120 may half the voltage region of the differential capacity profile, and classify a low voltage region as the criterion region RR and a high voltage region as the target region TR.
In the embodiment of
The control unit 120 may be configured to determine a peak with the greatest differential capacity in the criterion region RR as the criterion peak, and determine a peak with the greatest differential capacity in the target region TR as the target peak.
For example, in the embodiment of
The control unit 120 may be configured to diagnose the state of the battery as an unusable state when the differential capacity value of the criterion peak exceeds the differential capacity value of the target peak, and diagnose the state of the battery as a usable state when the differential capacity value of the criterion peak is less than or equal to the differential capacity value of the target peak.
In general, in the differential capacity profile, as the battery degrades, the differential capacity value corresponding to the target peak may be reduced. That is, in the embodiment of
In the embodiment of
Preferably, the control unit 120 may be configured to block charging and discharging of the second battery so that the second battery diagnosed as an unusable state is not used. For example, the control unit 120 may block charging and discharging of the second battery by controlling the relay connected to the positive electrode terminal and/or the negative electrode terminal of the second battery to a turn-off state. As another example, in order to indicate that the second battery is in an unusable state, the control unit 120 may label the state of the battery as an unusable state in the battery information about the second battery.
The battery management apparatus 100 according to the present disclosure may be applied to a BMS (Battery Management System). That is, the BMS according to the present disclosure may include the battery management apparatus 100 described above. In this configuration, at least some of the components of the battery management apparatus 100 may be implemented by supplementing or adding functions of the configuration included in the conventional BMS. For example, the profile generating unit 110, the control unit 120 and the storage unit 130 may be implemented as components of the BMS.
The battery management apparatus 100 according to the present disclosure may be provided in a battery pack. That is, the battery pack according to the present disclosure may include the above-described battery management apparatus 100 and one or more battery cells. In addition, the battery pack may further include electrical equipment (relays, fuses, etc.) and a case.
The positive electrode terminal of the battery B may be connected to the positive electrode terminal P+ of the battery pack 10, and the negative electrode terminal of the battery B may be connected to the negative electrode terminal P− of the battery pack 10.
A measuring unit 200 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 200 may be connected to a positive electrode terminal of the battery B through the first sensing line SL1, and may be connected to a negative electrode terminal of the battery B through the second sensing line SL2. The measuring unit 200 may measure the voltage of the battery B based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.
In addition, the measuring unit 200 may be connected to an ampere meter A through the third sensing line SL3. For example, the ampere meter A may be an ammeter or a shunt resistor capable of measuring the charging current and the discharging current of the battery B. The measuring unit 200 may calculate the amount of charge by measuring the charging current of the battery B through the third sensing line SL3. Also, the measuring unit 200 may calculate the amount of discharge by measuring the discharge current of the battery B through the third sensing line SL3.
One end of the charging and discharging device 20 may be connected to the positive electrode terminal P+ of the battery pack 10, and the other end may be connected to the negative electrode terminal P− of the battery pack 10. Therefore, the positive electrode terminal of the battery B, the positive electrode terminal P+ of the battery pack 10, the charging and discharging device 20, the negative electrode terminal P− of the battery pack 10, and the negative electrode terminal of the battery B may be electrically connected.
For example, the battery management apparatus 100 may be applied to a state diagnosing device for a reuse battery that diagnoses the state of a reuse battery.
Recently, as interest in eco-friendly energy increases, the use of batteries is increasing. Since a battery has a limit that cannot but degrade as it is used, whether or not the battery can be recycled may be determined according to the state of the battery. For example, a battery firstly used in a vehicle may be reused in an energy storage system (ESS).
In general, the battery in the MOL state may be reused in the secondary or tertiary use, but the battery in the EOL state may not be reusable. Accordingly, the battery management apparatus 100 may determine whether or not to reuse a collected battery by diagnosing the state of the collected battery in order to judge whether or not to reuse it.
For example, the battery management apparatus 100 may diagnose whether the state of the collected battery is an unusable state or a usable state by comparing the differential value of the criterion peak and the differential value of the target peak in the differential profile of the collected battery.
Preferably, each step of the battery management method may be performed by the battery management apparatus 100. Hereinafter, contents overlapping with the previously described contents will be omitted or briefly described.
The differential profile generating step (S100) is a step of generating a differential profile for a battery profile representing a corresponding relationship between voltage and capacity of a battery, and may be performed by the profile generating unit 110.
For example, the profile generating unit 110 may be configured to generate at least one of a differential voltage profile representing a corresponding relationship between a capacity and a differential voltage for the capacity and a differential capacity profile representing a corresponding relationship between a voltage and a differential capacity for the voltage.
The peak determining step (S200) is a step of determining a criterion peak and a target peak in the differential profile generated in the differential profile generating step (S100), and may be performed by the control unit 120.
For example, when the control unit 120 receives the differential voltage profile from the profile generating unit 110, the control unit 120 may classify the capacity region of the differential voltage profile into a criterion region RR and a target region TR, determine the criterion peak in the criterion region RR, and determine the target peak in the target region TR.
As another example, when the control unit 120 receives the differential capacity profile from the profile generating unit 110, the control unit 120 may classify the voltage region of the differential capacity profile into a criterion region RR and a target region TR, determine the criterion peak in the criterion region RR, and determine the target peak in the target region TR.
The battery state diagnosing step (S300) is a step of diagnosing the state of the battery based on a result of comparing the differential value of the criterion peak and the differential value of the target peak, and may be performed by the control unit 120.
For example, when the control unit 120 receives the differential voltage profile from the profile generating unit 110, the control unit 120 may diagnose the state of the battery as an unusable state if the differential voltage value of the criterion peak is less than the differential voltage value of the target peak. Conversely, if the differential voltage value of the criterion peak is equal to or greater than the differential voltage value of the target peak, the control unit 120 may diagnose the state of the battery as a usable state.
As another example, when the control unit 120 receives the differential capacity profile from the profile generating unit 110, the control unit 120 may diagnose the state of the battery as an unusable state if the differential capacity value of the criterion peak exceeds the differential capacity value of the target peak. In addition, if the differential capacity value of the criterion peak is less than or equal to the differential capacity value of the target peak, the control unit 120 may be configured to diagnose the state of the battery as a usable state.
The embodiments of the present disclosure described above may not be implemented only through an apparatus and a method, but may be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present disclosure or a recording medium on which the program is recorded. The program or recording medium may be easily implemented by those skilled in the art from the above description of the embodiments.
The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.
Additionally, many substitutions, modifications and changes may be made to the present disclosure described hereinabove by those skilled in the art without departing from the technical aspects of the present disclosure, and the present disclosure is not limited to the above-described embodiments and the accompanying drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0101551 | Aug 2021 | KR | national |
The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2022/011075 filed Jul. 27, 2022 which claims priority to Korean Patent Application No. 10-2021-0101551 filed on Aug. 2, 2021 in the Republic of Korea, the disclosures of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/011075 | 7/27/2022 | WO |
