Apparatus and method for diagnosing battery

Abstract

An apparatus for diagnosing a battery, according to an embodiment of the present invention, includes: a profile obtaining unit configured to obtain a differential profile indicating a correspondence relationship between a differential capacity and a voltage of a battery; and a control unit configured to determine a target peak in the differential profile, calculate a voltage change rate on the basis of the SOH of the battery and a target voltage of the target peak, and diagnose the state of the battery by comparing the calculated voltage change rate with a preset reference change rate.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0014930, filed on January 31, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly, to a battery diagnostic device and method for diagnosing the state of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] The present invention has been devised to solve the above problems, and its purpose is to provide a battery diagnosis device and method for diagnosing the state of a battery in a non-destructive manner.

[0007] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0008] A battery diagnostic device according to one aspect of the present invention may include a profile acquisition unit configured to acquire a differential profile indicating a correspondence between a differential capacity and a voltage of a battery; and a control unit configured to determine a target peak from the differential profile, calculate a voltage change rate based on the SOH of the battery and a target voltage of the target peak, and compare the calculated voltage change rate with a preset reference change rate to diagnose a state of the battery.

[0009] The above control unit may be configured to determine a peak having the largest differential capacity among a plurality of peaks included in the differential profile as the target peak.

[0010] The control unit may be configured to calculate the voltage change rate by calculating the ratio of the voltage change amount of the target peak to the SOH change amount of the battery.

[0011] The above control unit may be configured to calculate a ratio of the voltage change amount to the SOH change amount in an SOH section below a preset reference SOH.

[0012] The control unit may be configured to generate an SOH profile indicating a correspondence between the SOH of the battery and the target voltage of the target peak, and to calculate the voltage change rate in the reference SOH section of the SOH profile.

[0013] The control unit may be configured to diagnose the state of the battery as a normal deterioration state when the voltage change rate exceeds the reference change rate.

[0014] The control unit may be configured to diagnose the state of the battery as an abnormal deterioration state if the voltage change rate is less than the reference change rate.

[0015] The control unit may be configured to change at least one of the maximum allowable temperature, upper limit SOC, lower limit SOC, and upper limit C-rate set for the battery when the state of the battery is the normal degradation state.

[0016] The above control unit outputs an alarm when the state of the battery is in the abnormal deterioration state.

[0017] A battery pack according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0018] A vehicle according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0019] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a differential profile indicating a correspondence between a differential capacity and a voltage of a battery; a target peak determination step of determining a target peak from the differential profile; a voltage change rate calculation step of calculating a voltage change rate based on the SOH of the battery and the voltage of the target peak; and a diagnosis step of diagnosing a state of the battery by comparing the calculated voltage change rate with a preset reference change rate.

[0020] According to one aspect of the present invention, a battery diagnostic device has the advantage of being able to diagnose the state of a battery in a non-destructive manner by considering both the target voltage of the target peak and the SOH of the battery.

[0021] In addition, according to one aspect of the present invention, since the battery diagnosis device diagnoses the state of the battery according to the voltage change rate of the target peak for each SOH, there is an advantage in that the state of the battery can be tracked and diagnosed throughout the life cycle of the battery.

[0022] The effects of the present invention 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.

[0023] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0024] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0025] FIG. 2 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0026] FIG. 3 is a diagram schematically illustrating an SOH profile according to one embodiment of the present invention.

[0027] FIG. 4 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0028] FIG. 5 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0029] FIG. 6 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0030] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0031] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0032] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0033] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0034] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0035] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0036]

[0037] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0038] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0039] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110) and a control unit (120).

[0040] Here, a battery refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may also refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described herein below as referring to a single, independent cell.

[0041] The profile acquisition unit (110) can be configured to acquire a differential profile (DP) indicating a correspondence between the differential capacity and voltage of the battery.

[0042] For example, a battery profile is a profile that represents the relationship between voltage (V) and capacity (Q) when the battery's SOC is charged from a preset start SOC or 0% to a preset end SOC or 100%. As another example, a battery profile may represent the relationship between voltage (V) and capacity (Q) when the battery's SOC is discharged from a preset start SOC or 100% to a preset end SOC or 0%.

[0043] And, when the battery profile is differentiated with respect to voltage, a differential profile (DP) can be generated that represents the correspondence between the differential capacity (dQ / dV) and the voltage (V).

[0044] For example, there are no specific restrictions on the C-rate for charging or discharging to generate a battery profile. However, to obtain more accurate battery profiles and differential profiles (DP), it is desirable to charge or discharge the battery at a low rate. For example, a battery profile can be generated during the process of charging or discharging the battery at 0.05C.

[0045] For example, the profile acquisition unit (110) can directly receive the differential profile (DP) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the differential profile (DP) by being connected to the outside via wire and / or wirelessly and receiving the differential profile (DP).

[0046] As another example, the profile acquisition unit (110) can directly receive the battery profile of the battery from the outside. Furthermore, the profile acquisition unit (110) can differentiate the battery profile with respect to voltage to generate a differential profile (DP). That is, the profile acquisition unit (110) can be connected to the outside via wires and / or wirelessly to receive the battery profile and directly generate the differential profile (DP) from the battery profile, thereby acquiring the differential profile (DP).

[0047] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information, and may generate a differential profile (DP) based on the generated battery profile. In other words, the profile acquisition unit (110) may directly generate the differential profile (DP) based on the battery information, thereby acquiring the differential profile (DP).

[0048] FIG. 2 is a schematic diagram illustrating a differential profile (DP) according to one embodiment of the present invention. For example, the differential profile (DP) can be expressed as an XY graph in which the X-axis is set to voltage and the Y-axis is set to differential capacitance.

[0049] The profile acquisition unit (110) may be connected to the control unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the control unit (120) by wire and / or wirelessly. The profile acquisition unit may transmit the acquired differential profile (DP) to the control unit (120).

[0050] The control unit (120) may be configured to determine a target peak in the differential profile (DP).

[0051] Specifically, the differential profile (DP) may include multiple peaks (p1, p2, p3). Here, the peaks are local maxima of the differential profile (DP), which are points where the instantaneous rate of change of the differential capacitance with respect to the voltage is 0. The control unit (120) may determine one of the multiple peaks (p1, p2, p3) included in the differential profile (DP) as a target peak based on the voltage or the differential capacitance.

[0052] Preferably, the control unit (120) may be configured to determine a peak having the largest differential capacity among a plurality of peaks (p1, p2, p3) included in the differential profile (DP) as the target peak.

[0053] For example, in the embodiment of FIG. 2, the differential profile (DP) may include a first peak (p1), a second peak (p2), and a third peak (p3). Since the differential capacity of the third peak (p3) is the largest among the first to third peaks (p1, p2, p3), the control unit (120) may determine the third peak (p3) as the target peak.

[0054] The control unit (120) may be configured to calculate a voltage change rate based on the state of health (SOH) of the battery and the target voltage of the target peak.

[0055] Specifically, the control unit (120) can calculate the rate of change in the target voltage of the target peak as the SOH of the battery decreases. To this end, data regarding the target voltage for each SOH of the battery may be stored in advance. That is, data regarding the target voltage for each SOH measured in the past for the battery may be stored in advance.

[0056] In one embodiment, the control unit (120) can calculate the capacity of the battery from the battery profile and / or the differential profile (DP). In addition, the control unit (120) can calculate the SOH of the battery by calculating the ratio between the calculated capacity and the preset initial capacity of the battery. For example, the control unit (120) can calculate the SOH of the battery by calculating the formula "calculated capacity ÷ initial capacity × 100."

[0057] In another embodiment, the profile acquisition unit (110) and / or the control unit (120) may receive the SOH of the battery from an external source. For example, the profile acquisition unit (110) may receive the SOH of the battery together with battery-related information (at least one of battery information, a battery profile, and a differential profile (DP)) from an external source, and the control unit (120) may receive the SOH of the battery from the profile acquisition unit (110). As another example, the control unit (120) may directly receive information regarding the SOH of the battery from an external device.

[0058] The control unit (120) can be configured to calculate the voltage change rate by calculating the ratio of the voltage change amount of the target voltage to the SOH change amount of the battery.

[0059] For example, the control unit (120) can calculate the voltage change rate by calculating the formula “voltage change amount ÷ SOH change amount.”

[0060] FIG. 3 is a schematic diagram illustrating an SOH profile according to one embodiment of the present invention. For example, the SOH profile can be expressed as an XY graph in which the X-axis is set to SOH and the Y-axis is set to voltage. Specifically, FIG. 3 includes a first SOH profile (P1) for a first battery, a second SOH profile (P2) for a second battery, and a third SOH profile (P3) for a third battery.

[0061] For example, in the embodiment of FIG. 3, it is assumed that the voltage change rates of the first to third SOH profiles (P1, P2, P3) are calculated based on the reference SOH. The SOH change amount of the first SOH profile (P1) is "S1-S0(%)", and the voltage change amount of the first SOH profile (P1) is "vf1-vi1[V]". The SOH change amount of the second SOH profile (P2) is "S2-S0(%)", and the voltage change amount of the second SOH profile (P2) is "vf2-vi2[V]". The SOH change amount of the third SOH profile (P3) is "S3-S0(%)", and the voltage change amount of the third SOH profile (P3) is "vf3-vi3[V]". Here, the voltage change amount of the first SOH profile (P1) may be positive, the voltage change amount of the second SOH profile (P2) may be 0 [V], and the voltage change amount of the third SOH profile (P3) may be negative.

[0062] In the embodiment of FIG. 3, the voltage of the first SOH profile (P1) decreases around SOH 94%, but increases in the SOH section from s0 to s1. Therefore, the voltage change amount of the first SOH profile (P1) can be calculated as a positive number. That is, even if the voltage increases or decreases in some SOH sections, the voltage change amount for the SOH profile can be calculated based on the voltage change in the entire SOH section considered.

[0063] The control unit (120) can be configured to diagnose the state of the battery by comparing the calculated voltage change rate with a preset reference change rate.

[0064] Specifically, the reference change rate may be a preset reference value for distinguishing the battery's condition. Therefore, the control unit (120) can diagnose the battery's condition by directly comparing the calculated voltage change rate with the reference change rate. Preferably, the control unit (120) can compare the magnitude of the calculated voltage change rate with the reference change rate.

[0065] For example, the control unit (120) may be configured to diagnose the battery's condition as a normal degradation state if the voltage change rate exceeds a reference change rate. Here, a normal degradation state means that the battery's degradation falls within a pre-designed normal degradation category. For example, a normal degradation state means that the active material contained in the battery is degraded, but no abnormal degradation pattern is observed.

[0066] As another example, the control unit (120) may be configured to diagnose the battery's condition as an abnormal degradation state if the voltage change rate is below a reference change rate. Here, an abnormal degradation state means that the battery's degradation does not fall within a pre-designed normal degradation category. For example, an abnormal degradation state means a condition in which lithium plating occurs, in which lithium metal is precipitated from the battery's negative electrode.

[0067] The battery diagnostic device (100) has the advantage of being able to diagnose the state of the battery in a non-destructive manner by considering the target voltage of the target peak and the SOH of the battery together.

[0068] In addition, since the battery diagnosis device (100) diagnoses the state of the battery according to the voltage change rate of the target peak for each SOH, it has the advantage of being able to track and diagnose the state of the battery throughout the entire cycle of the battery.

[0069]

[0070] Meanwhile, the profile acquisition unit (110) and the control unit (120) provided in the battery diagnostic device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the profile acquisition unit (110) and the control unit (120) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the profile acquisition unit (110) and the control unit (120). The memory may be located inside or outside the profile acquisition unit (110) and the control unit (120), and may be connected to the profile acquisition unit (110) and the control unit (120) by various well-known means.

[0071] In addition, the battery diagnostic device (100) may further include a storage unit (130). The storage unit (130) may store data or programs required for each component of the battery diagnostic device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (130) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (130) may store program codes defining processes executable by the profile acquisition unit (110) and the control unit (120).

[0072] For example, the storage unit (130) can store the differential profile (DP) acquired by the profile acquisition unit (110). In addition, the storage unit (130) can store mapping information between the SOH and the voltage change rate for the battery. In other words, the storage unit (130) can store various data used to diagnose the condition of the battery.

[0073]

[0074] Preferably, the control unit (120) is located in the target voltage region (VR) of the differential profile (DP), and can determine the peak with the largest differential capacity as the target peak.

[0075] Specifically, the control unit (120) is located in a target voltage range (VR) from the voltage of the first peak (p1) to a predetermined voltage, and can determine the peak with the largest differential capacity as the target peak (tp).

[0076] For example, in the embodiment of FIG. 2, the voltage of the first peak (p1) is Va [V]. The target voltage range (VR) may be preset as a voltage range from Va [V] to voltage Vb [V]. Here, the voltage Vb [V] may be a voltage that is greater by a predetermined percentage than the voltage Va of the first peak (p1). For example, Vb [V] may be a voltage that is 10% greater than Va [V], so if Va [V] is 3.5 [V], Vb [V] may be 3.85 [V].

[0077] Since the battery diagnostic device (100) determines the target peak by limiting the target voltage range (VR), the time for determining the target peak can be shortened. In addition, if the battery is significantly degraded, the differential capacity of the second peak (p2) may be smaller than that of the first peak (p1) or the third peak (p3). Even in such cases, the battery diagnostic device (100) has the advantage of being able to consistently determine the second peak (p2) as the target peak (tp) by determining the target peak (tp) in the target voltage range (VR).

[0078]

[0079] The control unit (120) can be configured to calculate the ratio of voltage change to SOH change in the SOH section below a preset reference SOH.

[0080] Specifically, the control unit (120) can diagnose the state of the battery for the SOH section below the reference SOH, excluding the initial SOH section.

[0081] Typically, during the battery design process, lithium metal may precipitate on the cathode surface, and the target voltage at the target peak may decrease due to the cathode stabilization reaction in the initial cycle. Since such cases cannot be considered as abnormal battery deterioration, the control unit (120) can calculate the ratio of voltage change to SOH change in the SOH section below the preset reference SOH.

[0082] The reference SOH may be preset to an SOH that can be determined experimentally or theoretically by only correlating changes in the target voltage with the battery's deterioration state. For example, the reference SOH may be set to any SOH range between less than 100% and greater than 90%. Preferably, the reference SOH may be set to any SOH range between less than 98% and greater than 96%.

[0083] That is, the control unit (120) can calculate the SOH change amount using the reference SOH as the starting SOH, and calculate the voltage change amount using the target voltage corresponding to the reference SOH as the starting voltage. In addition, the control unit (120) can calculate the voltage change rate by calculating the ratio between the calculated SOH change amount and the voltage change amount.

[0084] For example, in the embodiment of FIG. 3, the reference SOH may be preset to s0[%]. Accordingly, the control unit (120) may calculate the voltage change rate in the SOH section below the reference SOH (s0), and diagnose the state of the battery based on the calculated voltage change rate.

[0085] The battery diagnostic device (100) according to one embodiment of the present invention can diagnose the battery condition more conservatively by diagnosing the battery condition within a limited SOH range. Therefore, the battery diagnostic device (100) can improve the diagnostic accuracy of the battery condition.

[0086]

[0087] Preferably, the control unit (120) may be configured to set the usage conditions of the battery in response to the diagnosis results.

[0088] Specifically, the control unit (120) can appropriately change the preset usage conditions to correspond to the state of the battery.

[0089] For example, if the battery is in a normal degradation state, the control unit (120) may be configured to change at least one of the maximum allowable temperature, the upper limit SOC, the lower limit SOC, and the upper limit C-rate set for the battery. As described above, the normal degradation state means a state in which the battery is degraded within a normal range. However, even if the battery is in a normal degradation state, if this state continues, the degradation of the battery may gradually accelerate. Therefore, the control unit (120) may prevent the degradation of the battery from gradually accelerating by changing at least one of the maximum allowable temperature, the upper limit SOC, the lower limit SOC, and the upper limit C-rate of the battery.

[0090] As another example, the control unit (120) may be configured to output an alarm if the battery is in an abnormal deterioration state. As described above, abnormal deterioration refers to a state in which the battery deteriorates beyond the normal range. Therefore, the control unit (120) can immediately output an alarm to notify the outside world of the battery's condition. For example, the control unit (120) may output an alarm notifying the battery's condition to an alarm unit (not shown), a display unit (not shown), a user terminal (not shown), and a server (not shown) connected by wire and / or wirelessly.

[0091] The battery diagnostic device (100) can increase the expected lifespan of a battery by taking appropriate measures in response to the diagnostic results. Furthermore, the battery diagnostic device (100) can prevent potential accidents caused by the battery by immediately notifying the external party of the battery's condition when the battery is in an abnormal state of deterioration.

[0092]

[0093] The battery diagnosis device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery diagnosis device (100) described above. In this configuration, at least some of the components of the battery diagnosis device (100) can be implemented by supplementing or adding to the functions of the 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 diagnosis device (100) can be implemented as components of the BMS.

[0094] In addition, the battery diagnostic device (100) according to the present invention may be installed in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0095] FIG. 4 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0096] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0097] The measuring unit (12) can be connected to a first sensing line (SL1), a second sensing line (SL2), and a third sensing line (SL3). Specifically, the measuring unit (12) can be connected to a positive terminal of the battery (11) through the first sensing line (SL1), and can be connected to a negative terminal of the battery (11) through the second sensing line (SL2). The measuring unit (12) can measure the voltage of the battery (11) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0098] And, the measuring unit (12) can be connected to the current measuring unit (A) through the third sensing line (SL3). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (11). The measuring unit (12) can measure the charging current of the battery (11) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (12) can measure the discharging current of the battery (11) through the third sensing line (SL3) to calculate the discharging amount.

[0099] For example, the profile acquisition unit (110) can receive battery information about the voltage and current of the battery from the measurement unit (12). Then, the profile acquisition unit (110) can generate a battery profile and a differential profile (DP) based on the battery information.

[0100] As another example, the profile acquisition unit (110) can receive a battery profile from the measurement unit (12). Then, the profile acquisition unit (110) can generate a differential profile (DP) based on the battery profile.

[0101] As another example, the profile acquisition unit (110) can receive a differential profile (DP) from the measurement unit (12).

[0102] An external device may be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (10). For example, the external device may be a charging device or a load. In addition, the positive terminal of the battery (11), the positive terminal (P+) of the battery pack (10), the external device, the negative terminal (P-) of the battery pack (10), and the negative terminal of the battery (11) may be electrically connected.

[0103]

[0104] FIG. 5 is a schematic drawing of a vehicle (500) according to another embodiment of the present invention.

[0105] Referring to FIG. 5, a battery pack (510) according to an embodiment of the present invention may be included in a vehicle (500), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (510) may drive the vehicle (500) by supplying power to a motor through an inverter provided in the vehicle (500). Here, the battery pack (510) may include a battery diagnostic device (100). That is, the vehicle (500) may include a battery diagnostic device (100). In this case, the battery diagnostic device (100) may be an onboard device included in the vehicle (500).

[0106]

[0107] FIG. 6 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0108] Referring to FIG. 6, the battery diagnosis method may include a profile acquisition step (S100), a target peak determination step (S200), a voltage change rate calculation step (S300), and a diagnosis step (S400).

[0109] Preferably, each step of the battery diagnosis method can be performed by a battery diagnosis device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.

[0110] The profile acquisition step (S100) is a step of acquiring a differential profile (DP) indicating a correspondence between the differential capacity and voltage of the battery, and can be performed by the profile acquisition unit (110).

[0111] For example, the profile acquisition unit (110) can directly receive the differential profile (DP) of the battery from the outside. That is, the profile acquisition unit (110) can acquire the differential profile (DP) by being connected to the outside via wire and / or wirelessly and receiving the differential profile (DP).

[0112] As another example, the profile acquisition unit (110) can directly receive the battery profile of the battery from the outside. Furthermore, the profile acquisition unit (110) can differentiate the battery profile with respect to voltage to generate a differential profile (DP). That is, the profile acquisition unit (110) can be connected to the outside via wires and / or wirelessly to receive the battery profile and directly generate the differential profile (DP) from the battery profile, thereby acquiring the differential profile (DP).

[0113] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information, and may generate a differential profile (DP) based on the generated battery profile. In other words, the profile acquisition unit (110) may directly generate the differential profile (DP) based on the battery information, thereby acquiring the differential profile (DP).

[0114] The target peak determination step (S200) is a step of determining a target peak in a differential profile (DP), and can be performed by the control unit (120).

[0115] Preferably, the control unit (120) may be configured to determine a peak having the largest differential capacity among a plurality of peaks included in the differential profile (DP) as the target peak.

[0116] The voltage change rate calculation step (S300) is a step of calculating the voltage change rate based on the SOH of the battery and the target voltage of the target peak, and can be performed by the control unit (120).

[0117] For example, the control unit (120) may be configured to calculate the voltage change rate by calculating the ratio of the voltage change amount of the target voltage to the SOH change amount of the battery.

[0118] The diagnosis step (S400) is a step for diagnosing the state of the battery by comparing the calculated voltage change rate with a preset reference change rate, and can be performed by the control unit (120).

[0119] For example, the control unit (120) may be configured to diagnose the battery's condition as a normal deterioration state if the voltage change rate exceeds a reference change rate. As another example, the control unit (120) may be configured to diagnose the battery's condition as an abnormal deterioration state if the voltage change rate is less than a reference change rate.

[0120] Furthermore, the control unit (120) can appropriately change the preset usage conditions to correspond to the state of the battery.

[0121] For example, the control unit (120) may be configured to change at least one of the maximum allowable temperature, upper limit SOC, lower limit SOC, and upper limit C-rate set for the battery if the battery is in a normal deterioration state. As another example, the control unit (120) may be configured to output an alarm if the battery is in an abnormal deterioration state.

[0122]

[0123] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0124] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0125] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0126]

[0127] (Explanation of symbols)

[0128] 10: Battery pack

[0129] 11: Battery

[0130] 12: Measurement section

[0131] 100: Battery Diagnostic Device

[0132] 110: Profile acquisition section

[0133] 120: Control unit

[0134] 130: Storage

[0135] 500: Car

[0136] 510: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a differential profile indicating a correspondence between the differential capacity and voltage of the battery; and A battery diagnosis device characterized by including a control unit configured to determine a target peak from the differential profile, calculate a voltage change rate based on the SOH of the battery and the target voltage of the target peak, and diagnose the state of the battery by comparing the calculated voltage change rate with a preset reference change rate.

2. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to determine the peak with the largest differential capacity among the plurality of peaks included in the differential profile as the target peak.

3. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the voltage change rate by calculating the ratio of the voltage change amount of the target voltage to the SOH change amount of the battery.

4. In paragraph 3, The above control unit, A battery diagnostic device characterized in that it is configured to calculate the ratio of the voltage change amount to the SOH change amount in the SOH section below the preset reference SOH.

5. In paragraph 1, The above control unit, If the voltage change rate exceeds the reference change rate, the battery's condition is diagnosed as a normal deterioration state, A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as an abnormal deterioration state when the voltage change rate is less than the reference change rate.

6. In paragraph 5, The above control unit, A battery diagnostic device characterized in that, when the state of the battery is the normal degradation state, at least one of the maximum allowable temperature, upper limit SOC, lower limit SOC, and upper limit C-rate set for the battery is changed.

7. In paragraph 5, The above control unit, A battery diagnostic device characterized in that it is configured to output an alarm when the state of the battery is the abnormal deterioration state.

8. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 7.

9. A vehicle including a battery diagnostic device according to any one of paragraphs 1 to 7.

10. A profile acquisition step for acquiring a differential profile representing the correspondence between the differential capacity and voltage of the battery; A target peak determination step for determining a target peak in the above differential profile; A voltage change rate calculation step for calculating a voltage change rate based on the SOH of the battery and the target voltage of the target peak; and A battery diagnosis method characterized by including a diagnosis step of diagnosing the state of the battery by comparing the calculated voltage change rate with a preset reference change rate.

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