Battery management device and method

Abstract

A battery management device according to one embodiment of the present invention includes a profile acquisition unit configured to acquire a differential profile showing the correspondence between the differential capacity and voltage of a battery, and a control unit configured to determine a plurality of peaks from the differential profile, calculate the capacity for each of a plurality of voltage intervals distinguished based on the plurality of peaks, calculate the rate of change of capacity for each of the plurality of voltage intervals based on the calculated plurality of capacities and a preset reference capacity, and diagnose the state of the battery according to the calculated plurality of rate of change of capacity.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0104429 filed on August 9, 2023, and all the contents disclosed in the specification and drawings of the said application are incorporated into this application.

[0002] The present invention relates to a battery management device and method, and more particularly, to a battery management device and method for diagnosing the state of a battery and controlling the usage conditions of the battery according to the diagnosis result.

Background Art

[0003] In recent years, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, artificial satellites, etc. has become full-scale, research on high-performance batteries that can be repeatedly charged and discharged has been actively conducted.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries are attracting attention for their advantages of being able to be freely charged and discharged because they hardly exhibit a memory effect compared to nickel-based batteries, having a very low self-discharge rate, and having a high energy density.

[0005] Although various studies have been conducted on such batteries from the viewpoints of increasing capacity and density, improving lifespan and safety is also important. In order to improve the safety of a battery, a technology for accurately diagnosing the current state of the battery is required.

Summary of the Invention

Problems to be Solved by the Invention

[0006] This invention was devised to solve the above-mentioned problems, and aims to provide a battery management device and method that can track and diagnose the battery's condition and increase its lifespan.

[0007] Other objects and advantages of the present invention can be understood from the following description and more clearly from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0008] A battery management device according to one aspect of the present invention includes a profile acquisition unit configured to acquire a differential profile showing the correspondence between the differential capacity and voltage of a battery, and a control unit configured to determine a plurality of peaks from the differential profile, calculate the capacity for each of a plurality of voltage intervals distinguished based on the plurality of peaks, calculate the rate of change of capacity for each of the plurality of voltage intervals based on the calculated plurality of capacities and a preset reference capacity, and diagnose the state of the battery according to the calculated plurality of rate of change of capacity.

[0009] The control unit may be configured to compare the rate of change of capacity in a target voltage section among the plurality of voltage sections with the rate of change of capacity in the remaining voltage sections, and to diagnose the state of the battery according to the result of the comparison.

[0010] The control unit may be configured to diagnose the battery's state as an accelerated degradation state if the rate of change of capacity in the target voltage interval is the smallest among a plurality of rate of change of capacity.

[0011] The control unit may be configured to adjust the pre-set operating conditions for the battery based on the state of the battery.

[0012] The control unit may be configured to reduce at least one of the charging termination voltage and upper limit temperature based on at least one of the multiple capacity change rates if the battery state is diagnosed as being in an accelerated degradation state.

[0013] The reference capacitance may be configured to be set for each of the plurality of voltage intervals.

[0014] The control unit may be configured to compare the capacitance of the plurality of voltage intervals with the corresponding reference capacitance and calculate the capacitance change rate for each of the plurality of voltage intervals.

[0015] The control unit may be configured to calculate the multiple capacitances by integrating each of the multiple voltage intervals with respect to voltage in the differential profile.

[0016] The control unit may be configured to determine the minimum point of the differential profile as the peak.

[0017] A battery pack according to another aspect of the present invention includes a battery management device according to one aspect of the present invention.

[0018] An automobile according to yet another aspect of the present invention includes a battery management device according to one aspect of the present invention.

[0019] A battery management method according to yet another aspect of the present invention includes: a profile acquisition step of acquiring a differential profile showing the correspondence between the differential capacity and voltage of a battery; a peak determination step of determining a plurality of peaks from the differential profile; a capacity calculation step of calculating the capacity for each of a plurality of voltage intervals distinguished based on the plurality of peaks; a capacity change rate calculation step of calculating the capacity change rate for each of the plurality of voltage intervals based on the calculated plurality of capacities and a preset reference capacity; and a state diagnosis step of diagnosing the state of the battery according to the calculated plurality of capacity change rates. [Effects of the Invention]

[0020] According to one aspect of the present invention, a battery management device can distinguish voltage intervals based on a plurality of peaks and diagnose the state of a battery according to the rate of change in capacity of the distinguished voltage intervals. That is, the battery management device can track and diagnose the state of the battery in consideration of the change in the rate of change in capacity for each voltage interval of the battery.

[0021] Also, the plurality of voltage intervals are distinguished based on peaks that reflect the state of the battery at that time. Therefore, the battery management device can accurately diagnose the state of the battery at each time point based on the rate of change in capacity for each voltage interval.

[0022] Also, according to one aspect of the present invention, since the usage conditions of the battery are appropriately adjusted according to the state of the battery, the life of the battery can be increased.

[0023] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0024] The drawings attached to this specification serve to make it easier to understand the technical idea of the present invention together with the detailed description of the invention to be described later, and the present invention is not to be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0025] [Figure 1] It is a diagram schematically showing a battery management device according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing a differential profile according to an embodiment of the present invention. [Figure 3] It is a diagram schematically showing another differential profile according to an embodiment of the present invention. [Figure 4] It is a diagram schematically showing yet another differential profile according to an embodiment of the present invention. [Figure 5]This figure schematically shows yet another differential profile according to one embodiment of the present invention. [Figure 6] This figure shows the capacitance for each voltage interval of multiple differential profiles according to one embodiment of the present invention. [Figure 7] This figure shows the capacitance change rate for each voltage interval of multiple differential profiles according to one embodiment of the present invention. [Figure 8] This figure shows an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 9] This figure schematically shows an automobile according to yet another embodiment of the present invention. [Figure 10] This figure schematically illustrates a battery management method according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0026] The terms and words used in this specification and in the claims are not to be interpreted in a manner limited to their general and dictionary meanings, but rather in a manner corresponding to the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best describe their invention.

[0027] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application.

[0028] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such detailed description will be omitted.

[0029] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of several components from others, and these terms do not limit the components themselves.

[0030] When a part of the specification "includes" a certain component, unless otherwise specified, this does not exclude other components, but rather means that it may include other components.

[0031] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only "direct connections" but also "indirect connections" mediated by other elements.

[0032] A battery refers to a single, physically separable, independent cell equipped with a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. Alternatively, a battery may refer to a battery module in which multiple cells are connected in series and / or parallel. For the sake of explanation, in the following, a battery will be described as a single, independent cell.

[0033] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0034] Figure 1 is a schematic diagram showing a battery management device 100 according to one embodiment of the present invention.

[0035] Referring to Figure 1, the battery management device 100 includes a profile acquisition unit 110 and a control unit 120.

[0036] The profile acquisition unit 110 may be configured to acquire a differential profile that shows the correspondence between the differential capacity and voltage of the battery.

[0037] Here, differential capacitance represents the instantaneous rate of change of capacitance with respect to voltage. That is, differential capacitance is the value obtained by differentiating capacitance with respect to voltage, and can be expressed as "dQ / dV".

[0038] Specifically, a battery profile is a profile that shows the correspondence between voltage (V) and capacity (Q) when the battery's State of Charge (SOC) is charged from 0% to 100%. Furthermore, differentiating the battery profile with respect to voltage can generate a differential profile showing the correspondence between differential capacity (dQ / dV) and voltage (V). Conversely, the battery profile may also show the correspondence between voltage (V) and capacity (Q) when the battery's SOC is discharged from 100% to 0%.

[0039] For example, the C rate is not particularly limited when charging or discharging to generate a battery profile. However, it is preferable to charge or discharge the battery at a lower rate in order to obtain a more accurate battery profile and differential profile. For example, a battery profile can be generated during the process of charging or discharging the battery at 0.05C.

[0040] For example, the profile acquisition unit 110 can directly receive the differential profile of the battery from an external source. That is, the profile acquisition unit 110 can acquire the differential profile by receiving the differential profile via a wired and / or wireless connection to an external source.

[0041] As another example, the profile acquisition unit 110 may receive battery information regarding the battery's voltage and capacity. The profile acquisition unit 110 may then generate a battery profile based on the received battery information and generate a differential profile based on the generated battery profile. In other words, the profile acquisition unit 110 may acquire a differential profile by directly generating a differential profile based on the battery information.

[0042] Figures 2 to 5 schematically show multiple differential profiles (reference differential profile PR, first differential profile PA, second differential profile PB, and third differential profile PC) according to one embodiment of the present invention.

[0043] The embodiment shown in Figure 2 illustrates the reference differential profile PR of a battery in the BOL (Beginning of Life) state. For example, the reference differential profile PR is the differential profile of the battery during the first charge-discharge cycle.

[0044] The embodiment shown in Figure 3 illustrates the first differential profile PA of the battery. For example, the first differential profile PA is the differential profile of the battery after 100 charge-discharge cycles.

[0045] The embodiment shown in Figure 4 illustrates the second differential profile PB of the battery. For example, the second differential profile PB is the differential profile of the battery after 200 charge-discharge cycles.

[0046] The embodiment shown in Figure 5 illustrates the third differential profile PC of the battery. For example, the third differential profile PC is the differential profile of the battery after 300 charge-discharge cycles.

[0047] The profile acquisition unit 110 may be connected to the control unit 120 in a communicative manner. For example, the profile acquisition unit 110 may be connected to the control unit 120 by wire and / or wirelessly. The profile acquisition unit 110 may transmit the acquired differential profile to the control unit 120.

[0048] The control unit 120 may be configured to determine multiple peaks from the differential profile.

[0049] Specifically, the control unit 120 can determine a peak in the differential profile where the slope (instantaneous rate of change) is 0 and the general shape is convex downwards. That is, the slope on the low-voltage side is negative and the slope on the high-voltage side is positive around the peak. In other words, the control unit 120 can be configured to determine the peak at the minimum point of the differential profile.

[0050] For example, in the embodiments shown in Figures 2 to 5, the reference differential profile PR, the first differential profile PA, the second differential profile PB, and the third differential profile PC may include the first peak p1, the second peak p2, the third peak p3, and the fourth peak p4. Here, depending on the battery composition, the peaks that appear may differ from those in the embodiments shown in Figures 2 to 5. For example, in other batteries, the first peak p1 and the second peak p2 may not be distinguished and may appear as a single peak.

[0051] The control unit 120 may be configured to calculate the capacitance for each of several voltage intervals that are distinguished based on several peaks.

[0052] Specifically, the control unit 120 can distinguish the usable voltage range of the battery into multiple voltage ranges based on multiple peaks. For example, the control unit 120 can distinguish multiple voltage ranges based on voltage values ​​corresponding to multiple peaks.

[0053] For example, in the embodiments shown in Figures 2 to 5, each differential profile (reference differential profile PR, first differential profile PA, second differential profile PB, third differential profile PC) includes a first peak p1, a second peak p2, a third peak p3, and a fourth peak p4. Therefore, the control unit 120 can distinguish the voltage intervals of each differential profile (reference differential profile PR, first differential profile PA, second differential profile PB, third differential profile PC) into five distinct intervals. That is, the control unit 120 can distinguish each differential profile (reference differential profile PR, first differential profile PA, second differential profile PB, third differential profile PC) into a first voltage interval R1, a second voltage interval R2, a third voltage interval R3, a fourth voltage interval R4, and a fifth voltage interval R5.

[0054] The control unit 120 can then calculate the capacitance for each of the distinguished voltage intervals.

[0055] Specifically, a differential profile is a profile that shows the correspondence between voltage and differential capacitance. That is, in a differential profile, the area of ​​a voltage interval represents the battery capacity in that voltage interval. Therefore, the control unit 120 may be configured to calculate multiple capacities by integrating each of the multiple voltage intervals in the differential profile with respect to voltage.

[0056] Figure 6 shows the capacitance for each voltage interval of multiple differential profiles (reference differential profile PR, first differential profile PA, second differential profile PB, and third differential profile PC) according to one embodiment of the present invention.

[0057] In the reference differential profile PR, the capacitance corresponding to the first voltage interval R1 is Q10, the capacitance corresponding to the second voltage interval R2 is Q20, the capacitance corresponding to the third voltage interval R3 is Q30, the capacitance corresponding to the fourth voltage interval R4 is Q40, and the capacitance corresponding to the fifth voltage interval R5 is Q50.

[0058] In the first differential profile PA, the capacitance corresponding to the first voltage interval R1 is Q11, the capacitance corresponding to the second voltage interval R2 is Q21, the capacitance corresponding to the third voltage interval R3 is Q31, the capacitance corresponding to the fourth voltage interval R4 is Q41, and the capacitance corresponding to the fifth voltage interval R5 is Q51.

[0059] In the second differential profile PB, the capacitance corresponding to the first voltage interval R1 is Q12, the capacitance corresponding to the second voltage interval R2 is Q22, the capacitance corresponding to the third voltage interval R3 is Q32, the capacitance corresponding to the fourth voltage interval R4 is Q42, and the capacitance corresponding to the fifth voltage interval R5 is Q52.

[0060] In the third differential profile PC, the capacitance corresponding to the first voltage interval R1 is Q13, the capacitance corresponding to the second voltage interval R2 is Q23, the capacitance corresponding to the third voltage interval R3 is Q33, the capacitance corresponding to the fourth voltage interval R4 is Q43, and the capacitance corresponding to the fifth voltage interval R5 is Q53.

[0061] The control unit 120 may be configured to calculate the rate of change of capacitance for each of the multiple voltage intervals based on the multiple calculated capacitances and a preset reference capacitance.

[0062] Here, the reference capacitance may be configured to be set for each of several voltage intervals. For example, reference capacitances may be set for the first voltage interval R1, the second voltage interval R2, the third voltage interval R3, the fourth voltage interval R4, and the fifth voltage interval R5, respectively. More specifically, the first reference capacitance Q10 is set for the first voltage interval R1, the second reference capacitance Q20 is set for the second voltage interval R2, and the third reference capacitance Q30 is set for the third voltage interval R3. Similarly, the fourth reference capacitance Q40 is set for the fourth voltage interval R4, and the fifth reference capacitance Q50 is set for the fifth voltage interval R5. Here, it is preferable that the first reference capacitance Q10 to the fifth reference capacitance Q50 are independent capacitance values.

[0063] Specifically, the reference capacity for each of the multiple voltage intervals can be set to the capacity for each voltage interval in the reference differential profile PR. It is preferable to set the initial capacity information of the battery as reference information in order to track and diagnose the battery's state. Since the reference differential profile PR is the differential profile of the battery during the first charge-discharge cycle, the capacity for each voltage interval in the reference differential profile PR corresponds to the initial capacity information of the battery. Therefore, the capacity for each voltage interval in the reference differential profile PR can be set as the reference capacity for the corresponding voltage interval.

[0064] For example, in the embodiment shown in Figure 6, the reference capacitance of the first voltage section R1 is Q10, the reference capacitance of the second voltage section R2 is Q20, the reference capacitance of the third voltage section R3 is Q30, the reference capacitance of the fourth voltage section R4 is Q40, and the reference capacitance of the fifth voltage section R5 is Q50.

[0065] The control unit 120 may be configured to compare the capacitance of multiple voltage intervals with the corresponding reference capacitance and calculate the capacitance change rate for each of the multiple voltage intervals.

[0066] Specifically, the rate of change in capacity can be calculated as the ratio of the capacity to the reference capacity. For example, the control unit 120 can calculate the rate of change in capacity by using the formula "capacity ÷ reference capacity × 100". Note that the capacity and reference capacity are those within the same voltage range.

[0067] Furthermore, the 100 in the formula "capacity ÷ base capacity × 100" is a constant used to represent the rate of change in capacity within the range of 0% to 100%, and therefore can be omitted. When such a constant is omitted, the rate of change in capacity can have a value within the range of 0 to 1.

[0068] For example, in the embodiment shown in Figure 6, the capacitance change rate for the first voltage section R1 of the first differential profile PA is "Q11 ÷ Q10 × 100", the capacitance change rate for the second voltage section R2 is "Q21 ÷ Q20 × 100", the capacitance change rate for the third voltage section R3 is "Q31 ÷ Q30 × 100", the capacitance change rate for the fourth voltage section R4 is "Q41 ÷ Q40 × 100", and the capacitance change rate for the fifth voltage section R5 is "Q51 ÷ Q50 × 100". The capacitance change rates for each voltage section of the second differential profile PB and the third differential profile PC can be calculated using a similar method.

[0069] The control unit 120 may be configured to diagnose the battery status according to a plurality of calculated capacity change rates.

[0070] Specifically, the control unit 120 can diagnose the battery status by comparing the rate of change in capacity for each of several voltage intervals. In other words, the control unit 120 does not compare the rate of change in capacity at different points in time (cycles), but rather compares multiple rates of change in capacity at the same point in time (cycle).

[0071] For example, in the embodiment shown in Figure 3, the control unit 120 can diagnose the state of the battery at the point in time corresponding to the first differential profile PA by comparing the rate of change of capacity in the first voltage section R1 with the rate of change of capacity in the second voltage section R2, the rate of change of capacity in the third voltage section R3, and the rate of change of capacity in the fourth voltage section R4.

[0072] A battery management device 100 according to one embodiment of the present invention can distinguish voltage intervals based on multiple peaks and diagnose the state of the battery according to the rate of change in capacity for each distinguished voltage interval. In other words, the battery management device 100 can track and diagnose the state of the battery by considering the change in the rate of change in capacity for each voltage interval of the battery.

[0073] Furthermore, the multiple voltage intervals are distinguished based on a peak that reflects the battery's state at that particular time. Therefore, the battery management device 100 can accurately diagnose the battery's state at each point in time based on the rate of capacity change for each voltage interval.

[0074] On the other hand, the control unit 120 provided in the battery management device 100 may selectively include a processor, ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is implemented as software, the control unit 120 may be implemented as a collection of program modules. In this case, the program modules may be recorded in memory and executed by the control unit 120. The memory may be provided inside or outside the control unit 120 and may be connected to the control unit 120 by various well-known means.

[0075] The battery management device 100 may further include a storage unit 130. The storage unit 130 may store data and programs necessary for each component of the battery management device 100 to operate and function, or data generated during the process of operation and functioning. The type of storage unit 130 is not particularly limited, as long as it is a known information recording means that is known to be able to record, erase, update, and read data. For example, information recording means may include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, etc. The storage unit 130 may also store program code in which the process that can be executed by the control unit 120 is defined.

[0076] For example, the memory unit 130 may store the differential profile acquired by the profile acquisition unit 110. The memory unit 130 may also store the capacitance and capacitance change rate for each voltage interval calculated by the control unit 120. The control unit 120 can then access the memory unit 130 to acquire the necessary data.

[0077] Figure 7 shows the capacitance change rate for each voltage interval of multiple differential profiles (reference differential profile PR, first differential profile PA, second differential profile PB, and third differential profile PC) according to one embodiment of the present invention. Specifically, in Figure 7, the capacitance change rate for the first cycle is based on the reference differential profile PR in Figures 2 and 6, and the capacitance change rate for the 100th cycle is based on the first differential profile PA in Figures 3 and 6. The capacitance change rate for the 200th cycle is based on the second differential profile PB in Figures 4 and 6, and the capacitance change rate for the 300th cycle is based on the third differential profile PC in Figures 5 and 6.

[0078] Figure 7 shows the capacitance change rates for the first voltage section R1, the second voltage section R2 + third voltage section R3, the fourth voltage section R4, and the fifth voltage section R5. Here, since there was no significant difference in the capacitance change rate for the second voltage section R2, the capacitance change rate for the second voltage section R2 and the capacitance change rate for the third voltage section R3 were combined and shown as (R2 + R3).

[0079] The control unit 120 may be configured to compare the capacitance change rate of a target voltage section among a plurality of voltage sections with the capacitance change rate of the remaining voltage sections.

[0080] Specifically, the target voltage interval can be set to the highest voltage interval among multiple voltage intervals. For example, in the embodiment shown in Figure 6, the target voltage interval can be set to the fifth voltage interval R5.

[0081] Here, the voltage interval on the highest voltage side represents the degradation state of the high-potential region of the positive electrode. In such a voltage interval, the reaction of the positive electrode is actively observed, but the reaction of the negative electrode hardly occurs. For example, in such a voltage interval, the positive electrode potential increases significantly with increasing capacitance (or SOC). Conversely, even if the capacitance of the negative electrode increases, the negative electrode potential does not change or changes only slightly. Such a voltage interval is also called a negative electrode flat interval, where there is almost no change in the potential of the negative electrode. Therefore, the target voltage interval can be selected as the voltage interval on the highest voltage side where only the reaction of the positive electrode is actively observed.

[0082] The control unit 120 may be configured to diagnose the battery status according to the comparison results.

[0083] Specifically, the control unit 120 can diagnose the battery status by comparing the magnitudes of multiple capacity change rates. Preferably, the control unit 120 can compare the magnitude of the capacity change rate in the target voltage section with the capacity change rate in the remaining voltage sections.

[0084] For example, if the rate of change of capacity in the target voltage interval is the smallest among multiple rates of change of capacity, the control unit 120 may be configured to diagnose the battery state as an accelerated degradation state.

[0085] In the embodiment shown in Figure 7, the fifth voltage interval R5 is assumed to be the target voltage interval. In the 200th cycle, the rate of change of capacity in the fifth voltage interval R5 is the smallest among the multiple rate of change of capacity. The control unit 120 can diagnose the state of the battery in the 200th cycle as an accelerated degradation state. Similarly, in the 300th cycle, the rate of change of capacity in the fifth voltage interval R5 is also the smallest among the multiple rate of change of capacity, so the control unit 120 can diagnose the state of the battery in the 300th cycle as an accelerated degradation state.

[0086] Specifically, if the rate of change of capacity in the target voltage interval is the smallest among multiple rates of change of capacity, the control unit 120 may be configured to diagnose the battery state as a positive electrode degradation acceleration state.

[0087] In the embodiment shown in Figure 7, the control unit 120 can diagnose the battery state in the 200th and 300th cycles as an accelerated positive electrode degradation state.

[0088] As described above, the target voltage interval may best represent the degradation state of the high-potential side of the positive electrode. If the capacitance change rate in such a target voltage interval is smaller than that of the other voltage intervals, it indicates that the capacitance in the target voltage interval has decreased the most compared to the initial capacitance. In other words, when the capacitance degradation in the high-potential region of the positive electrode is most severe compared to other regions, the capacitance change rate in the target voltage interval may have the smallest value. Therefore, the control unit 120 can diagnose whether the degradation of the positive electrode is accelerating based on the result of comparing the capacitance change rate of the target voltage interval with the capacitance change rates of the remaining voltage intervals.

[0089] A battery management device 100 according to one embodiment of the present invention can diagnose an accelerated state of battery degradation, specifically an accelerated state of degradation of the battery's positive electrode. That is, the battery management device 100 can not only diagnose whether battery degradation is accelerating, but also specifically identify the electrode that is subject to accelerated degradation. Therefore, the battery management device 100 has the advantage of being able to diagnose the specific state of battery degradation.

[0090] The following describes an embodiment in which the control unit 120 adjusts the battery usage conditions according to the diagnosed battery status.

[0091] The control unit 120 may be configured to adjust the pre-set operating conditions for the battery based on the battery status.

[0092] For example, the operating conditions set for a battery may include the charging termination voltage, discharging termination voltage, upper temperature limit, and upper limit of the charge / discharge C-rate. Adjusting the operating conditions according to the battery's condition can delay battery degradation. This is because changing the operating conditions allows the battery to escape environments (or causes of degradation) that are prone to degradation.

[0093] For example, if the cause of battery degradation is capacity loss on the positive electrode high potential side, the control unit 120 can prevent a reaction from occurring on the positive electrode high potential side by reducing the charging termination voltage. Furthermore, the control unit 120 can prevent the battery reaction from becoming excessively active by reducing the upper temperature limit. In other words, the control unit 120 can prevent further degradation of the positive electrode by reducing the charging termination voltage and / or the upper temperature limit.

[0094] As another example, if rapid charging is the cause of battery degradation, the control unit 120 can prevent rapid charging from progressing by reducing the upper limit of the charge / discharge C rate.

[0095] As another example, if the cause of battery degradation is capacity loss on the high-potential side of the negative electrode, the control unit 120 can prevent a reaction from occurring on the high-potential side of the negative electrode by increasing the discharge termination voltage.

[0096] In other words, the control unit 120 can appropriately adjust the operating conditions according to the cause of deterioration.

[0097] Specifically, the control unit 120 can diagnose whether the battery is in a state of accelerated degradation. More specifically, the control unit 120 can diagnose whether the battery is in a state of accelerated positive electrode degradation. Therefore, if the control unit 120 diagnoses that the battery is in a state of accelerated degradation, it may be configured to reduce at least one of the charging termination voltage and the upper limit temperature.

[0098] A battery management device 100 according to one embodiment of the present invention can prevent further battery degradation by appropriately adjusting the operating conditions to address the causes of battery degradation. In other words, by adjusting the operating conditions of such a battery management device 100, the battery life can be increased.

[0099] The control unit 120 may be configured to reduce at least one of the charging termination voltage and upper limit temperature based on at least one of a plurality of capacity change rates if the battery state is diagnosed as being in an accelerated degradation state.

[0100] Specifically, the control unit 120 may determine the target voltage and / or target temperature based on at least one of a plurality of capacitance change rates.

[0101] In one embodiment, the control unit 120 may determine the target voltage and / or target temperature based on the capacitance change rate of a target voltage interval among a plurality of capacitance change rates. Here, mapping information of the target voltage and / or target temperature to the capacitance change rate of the target voltage interval may be stored in advance. The control unit 120 may use such mapping information to determine the target voltage and / or target temperature corresponding to the capacitance change rate of the target voltage interval.

[0102] In other embodiments, mapping information of the target voltage and / or target temperature to the rate of change of capacity in the target voltage range and the charge / discharge cycle may be stored in advance. The control unit 120 may use such mapping information to determine the target voltage and / or target temperature corresponding to the rate of change of capacity in the target voltage range and the charge / discharge cycle.

[0103] In yet another embodiment, the control unit 120 may calculate the difference between the capacitance change rate of the target voltage interval and the other capacitance change rates, and determine the target voltage and / or target temperature based on the sum of the calculated differences in the multiple capacitance change rates.

[0104] For example, suppose the charging termination voltage is 4.2V and the target voltage calculated based on multiple capacitance change rates is 10mV. The control unit 120 may reduce the charging termination voltage to 4.19V. As another example, suppose the upper temperature limit is 50°C and the target temperature calculated based on multiple capacitance change rates is 5°C. The control unit 120 may reduce the upper temperature limit to 45°C.

[0105] A battery management device 100 according to one embodiment of the present invention can be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the battery management device 100 described above. In such a configuration, at least some of the components of the battery management device 100 can be realized by complementing or adding to the functions of components included in a conventional BMS. For example, the profile acquisition unit 110, the control unit 120, and the storage unit 130 of the battery management device 100 can be realized as components of the BMS.

[0106] Furthermore, a battery management device 100 according to one embodiment of the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the above-described battery management device 100 and one or more battery cells. The battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0107] Figure 8 shows an exemplary configuration of a battery pack according to another embodiment of the present invention.

[0108] The positive terminal of battery 10 may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery 10 may be connected to the negative terminal P- of battery pack 1.

[0109] The measuring unit 20 can be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 20 can be connected to the positive terminal of the battery 10 through the first sensing line SL1 and to the negative terminal of the battery 10 through the second sensing line SL2. The measuring unit 20 can measure the voltage of the battery 10 based on the voltages measured in the first sensing line SL1 and the second sensing line SL2, respectively.

[0110] Furthermore, the measurement unit 20 can be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A may be an ammeter or shunt resistor capable of measuring the charging current and discharging current of the battery 10. The measurement unit 20 can measure the charging current of the battery 10 via the third sensing line SL3 and calculate the charge amount. The measurement unit 20 can also measure the discharging current of the battery 10 via the third sensing line SL3 and calculate the discharge amount.

[0111] The load can be connected at one end to the positive terminal P+ of the battery pack 1 and at the other end to the negative terminal P- of the battery pack 1. Therefore, the positive terminal of the battery 10, the positive terminal P+ of the battery pack 1, the load, the negative terminal P- of the battery pack 1, and the negative terminal of the battery 10 can be electrically connected.

[0112] For example, the load may be a charging and discharging device, or it may be the motor of an electric vehicle that receives power from the battery 10.

[0113] Figure 9 is a schematic diagram showing an automobile 900 according to yet another embodiment of the present invention.

[0114] Referring to Figure 9, a battery pack according to an embodiment of the present invention can be installed in an automobile 900 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 910 can drive the automobile 900 by supplying power to a motor through an inverter provided in the automobile 900. Here, the battery pack 910 may include a battery management device 100. That is, the automobile 900 may include a battery management device 100.

[0115] Figure 10 is a schematic diagram illustrating a battery management method according to yet another embodiment of the present invention.

[0116] Preferably, each step of the battery management method can be performed by the battery management device 100. For the sake of clarity, the following will either omit or briefly explain any content that overlaps with the above explanation.

[0117] The profile acquisition step S100 is a step of acquiring a differential profile that shows the correspondence between the differential capacity and voltage of the battery, and can be performed by the profile acquisition unit 110.

[0118] For example, in the embodiments shown in Figures 2 to 5, the profile acquisition unit 110 can acquire a reference differential profile PR, a first differential profile PA, a second differential profile PB, and a third differential profile PC.

[0119] The peak determination step S200 is a step of determining multiple peaks from the differential profile, which may be performed by the control unit 120.

[0120] For example, the control unit 120 may be configured to determine the minimum point of the differential profile as a peak.

[0121] For example, in the embodiments shown in Figures 2 to 5, the reference differential profile PR, the first differential profile PA, the second differential profile PB, and the third differential profile PC may include the first peak p1, the second peak p2, the third peak p3, and the fourth peak p4.

[0122] The capacitance calculation step S300 is a step of calculating the capacitance for each of several voltage intervals that are distinguished based on several peaks, and can be performed by the control unit 120.

[0123] Specifically, the control unit 120 may be configured to calculate multiple capacitances by integrating each of the multiple voltage intervals with respect to voltage in the differential profile.

[0124] In the embodiment shown in Figure 6, the control unit 120 can calculate the capacitances from the first voltage interval R1 to the fifth voltage interval R5 for the reference differential profile PR, the first differential profile PA, the second differential profile PB, and the third differential profile PC.

[0125] The capacity change rate calculation step S400 is a step of calculating the capacity change rate for each of the multiple voltage intervals based on the calculated multiple capacities and a preset reference capacity, and can be performed by the control unit 120.

[0126] Specifically, the control unit 120 may be configured to compare the capacitance of multiple voltage intervals with the corresponding reference capacitance and calculate the capacitance change rate for each of the multiple voltage intervals.

[0127] For example, in the embodiment shown in Figure 6, the reference capacitance for the first voltage section R1 is Q10, the reference capacitance for the second voltage section R2 is Q20, the reference capacitance for the third voltage section R3 is Q30, the reference capacitance for the fourth voltage section R4 is Q40, and the reference capacitance for the fifth voltage section R5 is Q50. The control unit 120 can calculate the capacitance change rate for each of the multiple voltage sections by calculating the ratio of capacitance to reference capacitance for each voltage section.

[0128] The status diagnosis step S500 is a step of diagnosing the state of the battery according to a plurality of calculated capacity change rates, and may be performed by the control unit 120.

[0129] Specifically, the control unit 120 can diagnose the battery status by comparing the rate of change in capacity for each of several voltage intervals.

[0130] For example, if the rate of capacity change in the target voltage interval is the smallest among multiple rate of capacity change, the control unit 120 can diagnose the battery's condition as an accelerated degradation state. The control unit 120 can then prevent rapid battery degradation by adjusting the battery's operating conditions.

[0131] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be implemented through a program that realizes the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such a program is recorded. Such a program or recording medium can be easily implemented by those skilled in the art based on the description of the embodiments described above.

[0132] As described above, the present invention has been explained with limited embodiments and drawings, but it goes without saying that the present invention is not limited thereto, and that various modifications and variations are possible within the equivalent scope of the technical idea and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0133] Furthermore, the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention pertains, without departing from the technical spirit of the invention, and is not limited by the embodiments described above and the accompanying drawings. For diverse modifications, all or part of each embodiment can be selectively combined to form the present invention. [Explanation of Symbols]

[0134] 1: Battery pack 10: Battery 20: Measuring part 100: Battery management device 110: Profile acquisition unit 120: Control Unit 130: Storage section 900: Automobile 910: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a differential profile showing the correspondence between the differential capacity and voltage of a battery, A battery management device comprising: a control unit configured to determine a plurality of peaks from the differential profile, calculate the capacity for each of a plurality of voltage intervals distinguished based on the plurality of the aforementioned peaks, calculate the rate of change of capacity for each of the plurality of voltage intervals based on the calculated plurality of capacities and a preset reference capacity, and diagnose the state of the battery according to the calculated plurality of rate of change of capacity.

2. The battery management device according to claim 1, wherein the control unit is configured to compare the rate of change of capacity of a target voltage section among the plurality of voltage sections with the rate of change of capacity of the remaining voltage sections, and to diagnose the state of the battery according to the result of the comparison.

3. The battery management device according to claim 2, wherein the control unit is configured to diagnose the state of the battery as an accelerated degradation state if the rate of change of capacity in the target voltage interval is the smallest among a plurality of rates of change of capacity.

4. The battery management device according to claim 1, wherein the control unit is configured to adjust the usage conditions set in advance for the battery based on the state of the battery.

5. The battery management device according to claim 4, wherein the control unit is configured to reduce at least one of the charging termination voltage and the upper limit temperature based on at least one of the plurality of capacity change rates when the state of the battery is diagnosed as being in an accelerated deterioration state.

6. The reference capacitance is configured to be set for each of the plurality of voltage intervals, The battery management device according to claim 1, wherein the control unit is configured to compare the capacity of the plurality of voltage intervals with the corresponding reference capacity and calculate the rate of change of capacity for each of the plurality of voltage intervals.

7. The battery management device according to claim 1, wherein the control unit is configured to integrate each of the plurality of voltage intervals with respect to voltage in the differential profile and calculate the plurality of capacities.

8. The battery management device according to claim 1, wherein the control unit is configured to determine the minimum point of the differential profile as the peak.

9. A battery pack including a battery management device according to any one of claims 1 to 8.

10. An automobile comprising a battery management device according to any one of claims 1 to 8.

11. A profile acquisition step to obtain a differential profile showing the correspondence between the differential capacity and voltage of the battery, A peak determination step in which multiple peaks are determined from the differential profile, A capacitance calculation step that calculates the capacitance for each of several voltage intervals distinguished based on the aforementioned peaks, A capacity change rate calculation step that calculates the capacity change rate for each of the multiple voltage intervals based on the multiple calculated capacities and a preset reference capacity, A battery management method comprising a state diagnosis step of diagnosing the state of the battery according to a plurality of calculated capacity change rates.

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