Apparatus and method for generating battery information

Abstract

A method for generating battery information according to an embodiment of the present invention comprises: a profile acquisition step of acquiring a differential profile indicating a correlation between a voltage and a differential capacity of a battery; a peak detection step of detecting a peak from the differential profile; a voltage comparison step of comparing a peak voltage corresponding to the peak with a preset reference voltage; a measurement resistance determination step of discharging the battery and determining, as a measurement resistance, a resistance measured for a predetermined time from a timepoint at which the discharge of the battery is started; and a diagnosis resistance determination step of determining a diagnosis resistance of the battery on the basis of the measurement resistance according to the comparison result of the voltage comparison step.

Description

Battery information generation device and method

[0001] The present invention relates to a battery information generating device and method, and more particularly, to a battery information generating device and method that generate battery information that more accurately reflects the state of a battery.

[0002] This application claims priority to Korean Application No. 10-2024-0022912, filed February 16, 2024, the entire disclosure of which is incorporated herein by reference.

[0003]

[0004] 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.

[0005] Currently commercialized batteries include nickel-cadmium batteries, nickel-metal hydride 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.

[0006] 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.

[0007] Based on the fact that the internal resistance of a battery increases as it degrades, the resistance measured at the beginning of discharge after the end of charging has been used as a degradation indicator. That is, the resistance calculated based on the amount of voltage change over a predetermined period of time from the start of discharge after the end of charging was used as a degradation indicator.

[0008] However, as the battery deteriorates, the overvoltage caused by polarization increases, so the voltage measured during resistance measurement actually decreases. Furthermore, due to this voltage decrease, the measured resistance is lower than the actual value.

[0009] In the case of a battery that shows a minimal change in resistance according to voltage in the high voltage range, the decrease in resistance due to the decrease in voltage is minimal, so there is no great need to correct the measured resistance.

[0010] However, for batteries that exhibit significant resistance changes with voltage in high-voltage ranges, the decrease in resistance due to voltage reduction must be considered. In other words, to more accurately calculate resistance as a degradation indicator, the measured resistance must be corrected to account for the voltage decrease.

[0011] Therefore, a technology is needed that can determine whether the measured resistance corresponds to a battery that needs to be compensated for, and if the need for compensation is recognized, can compensate for the measured resistance by taking into account the voltage reduction.

[0012]

[0013] The present invention has been devised to solve the above problems, and its purpose is to provide a battery information generation method and device for determining whether a battery needs to have its measured resistance corrected.

[0014] In addition, the present invention aims to provide a battery information generation method and device that corrects measured resistance by taking into account a voltage decrease when the need for correction is recognized.

[0015] 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.

[0016]

[0017] A battery information generation method according to one aspect of the present invention may include a profile acquisition step of acquiring a differential profile indicating a correspondence between a voltage and a differential capacity of a battery; a peak detection step of detecting a peak in the differential profile; a voltage comparison step of comparing a peak voltage corresponding to the peak with a preset reference voltage; a measured resistance determination step of performing a discharge on the battery and determining a resistance for a predetermined time from a discharge start time as a measured resistance; and a diagnostic resistance determination step of determining a diagnostic resistance of the battery based on the measured resistance according to a comparison result of the voltage comparison step.

[0018] The above diagnostic resistance determination step may include a step of determining the measured resistance as the diagnostic resistance if the peak voltage is less than the reference voltage.

[0019] The above measurement resistance determination step may further include a measurement voltage determination step of determining the voltage at the discharge start point as the measurement voltage if the peak voltage is higher than the reference voltage.

[0020] The above diagnostic resistance determination step may include a measurement resistance correction step of correcting the measurement resistance based on the measurement voltage, the peak voltage, and the preset resistance profile; and a step of determining the corrected measurement resistance as the diagnostic resistance.

[0021] The above resistance profile may be a profile that is preset to correspond to the battery and represents a correspondence relationship between voltage and resistance.

[0022] The above measurement resistance correction step may include a step of calculating a first value based on the measurement voltage and the target voltage; a step of calculating a second value based on the target voltage and the resistance profile; a step of calculating a third value based on the first value and the second value; and a step of calculating the corrected measurement resistance based on the third value and the measurement resistance.

[0023] The target voltage may be determined as a voltage that is higher than the reference voltage among the peak voltages.

[0024] The above first value may be the difference between the measured voltage and the target voltage.

[0025] The second value may be a rate of change of the resistance with respect to the voltage in the target voltage range of the resistance profile.

[0026] The above target voltage range may be a voltage range higher than the target voltage.

[0027] The third value may be a value obtained by multiplying the first value by the second value.

[0028] The above-mentioned corrected measurement resistance may be a value obtained by adding the third value to the above-mentioned measurement resistance.

[0029] According to another aspect of the present invention, a battery information generation device may include: a profile acquisition unit that acquires a differential profile indicating a correspondence between a voltage and a differential capacity of a battery; a voltage comparison unit that detects a peak in the differential profile and compares a peak voltage corresponding to the peak with a preset reference voltage; a measurement value determination unit that determines a resistance for a predetermined time from a discharge start time by discharging the battery as a measured resistance; and a diagnostic resistance determination unit that determines a diagnostic resistance of the battery based on the measured resistance according to a comparison result.

[0030] The above diagnostic resistance determining unit may be configured to determine the measured resistance as the diagnostic resistance if the peak voltage is less than the reference voltage.

[0031] The above measurement value determination unit may be configured to determine the voltage at the discharge start point as the measurement voltage if the peak voltage is higher than the reference voltage.

[0032] The above diagnostic resistance determination unit may be configured to correct the measured resistance based on the measured voltage, the peak voltage, and the preset resistance profile, and determine the corrected measured resistance as the diagnostic resistance.

[0033] The above resistance profile may be a profile that is preset to correspond to the battery and represents a correspondence relationship between voltage and resistance.

[0034] The diagnostic resistance determining unit may be configured to calculate a first value based on the measured voltage and the target voltage, calculate a second value based on the target voltage and the resistance profile, calculate a third value based on the first value and the second value, and calculate the corrected measured resistance based on the third value and the measured resistance.

[0035] The target voltage may be determined as a voltage that is higher than the reference voltage among the peak voltages.

[0036] A battery pack according to another aspect of the present invention may include a battery information generating device according to another aspect of the present invention.

[0037]

[0038] According to one aspect of the present invention, by determining whether the measured resistance is corrected through voltage comparison based on a differential profile, the diagnostic resistance can be determined more accurately.

[0039] According to one aspect of the present invention, when determining diagnostic resistance as a degradation indicator, the diagnostic resistance can be determined more accurately by taking into account the change in voltage during resistance measurement.

[0040] According to one aspect of the present invention, since the reference voltage is set by taking into account the state of the battery, the diagnostic resistance can be determined more accurately.

[0041] 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.

[0042]

[0043] 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.

[0044] FIG. 1 is a flowchart of a battery information generation method according to one embodiment of the present invention.

[0045] FIG. 2 is a schematic diagram illustrating a battery information generation device according to one embodiment of the present invention.

[0046] FIG. 3 is a flowchart illustrating in more detail the voltage comparison step, the measurement resistance determination step, and the diagnostic resistance determination step of the battery information generation method according to one embodiment of the present invention.

[0047] FIG. 4 is a flowchart illustrating in more detail the measurement resistance correction step of the battery information generation method according to one embodiment of the present invention.

[0048] FIG. 5 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0049] FIG. 6 is a diagram schematically illustrating a resistance profile according to one embodiment of the present invention.

[0050] FIG. 7 is a drawing illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.

[0051]

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058]

[0059] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0060] FIG. 1 is a flowchart of a battery information generation method according to one embodiment of the present invention.

[0061] FIG. 2 is a schematic diagram illustrating a battery information generation device (100) according to one embodiment of the present invention.

[0062] Referring to FIG. 1, the battery information generation method may include a profile acquisition step (S100), a peak detection step (S200), a voltage comparison step (S300), a measurement resistance determination step (S400), and a diagnostic resistance determination step (S500). Preferably, each step of the battery information generation method may be performed by a battery information generation device (100).

[0063] Referring to FIG. 2, the battery information generation device (100) may include a profile acquisition unit (110), a voltage comparison unit (120), a measurement value determination unit (130), and a diagnostic resistance determination unit (140).

[0064] FIG. 3 is a flowchart illustrating in more detail the voltage comparison step (S300), the measurement resistance determination step (S400), and the diagnostic resistance determination step (S500) of the battery information generation method according to one embodiment of the present invention.

[0065] 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.

[0066] FIG. 5 is a schematic diagram illustrating a differential profile (DP) according to one embodiment of the present invention.

[0067] In the embodiment of FIG. 5, the horizontal axis (X-axis) represents voltage (V), and the vertical axis (Y-axis) represents differential capacitance (dQ / dV).

[0068] The profile acquisition step (S100) is a step of acquiring a differential profile (DP) indicating a correspondence between the voltage and differential capacity of the battery, and can be performed by the profile acquisition unit (110).

[0069] Here, the differential capacitance represents the instantaneous rate of change of the capacitance with respect to the voltage. In other words, the differential capacitance can be expressed as 'dQ / dV' as the value obtained by differentiating the capacitance with respect to the voltage.

[0070] A battery profile is a profile that represents the relationship between voltage (V) and capacity (Q) during battery charging. Differentiating the battery profile with respect to voltage generates a differential profile (DP), which represents the relationship between differential capacity and voltage. In other words, a battery profile is acquired during the battery charging process, and a differential profile (DP) can be derived from the battery profile.

[0071] For example, there are no specific restrictions on the C-rate used to generate a battery profile. However, to obtain more accurate battery profiles and differential profiles (DPs), the battery should be charged at a low rate. For example, a battery profile can be generated while charging the battery at 0.05C.

[0072] 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) of the battery by being connected to the outside via wire and / or wirelessly and receiving the differential profile (DP).

[0073] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) can directly generate a differential profile (DP) based on the received battery information.

[0074] As another example, the profile acquisition unit (110) can measure the voltage and current of the battery. For example, the profile acquisition unit (110) can be connected to the positive and negative terminals of the battery and measure the voltage of the battery. In addition, the profile acquisition unit (110) can measure the charge and discharge current of the battery and calculate the capacity of the battery based on the measured current. In addition, the profile acquisition unit (110) can generate a differential profile (DP) based on the voltage and capacity of the battery.

[0075] The peak detection step (S200) is a step of detecting a peak in a differential profile (DP) and can be performed by a voltage comparison unit (120).

[0076] Here, the peak can be defined as the point where the slope (instantaneous rate of change) of the profile changes from a positive (+) value to a negative (-) value. That is, the slope on the low-voltage side around the peak is positive, and the slope on the high-voltage side is negative. In other words, the maximum point of the differential profile can be determined as the peak.

[0077] Referring to FIG. 5, multiple peaks (pk1, pk2, pk3, pk4, pk5) can be detected in the differential profile (DP).

[0078] The voltage comparison unit (120) can compare the peak voltage corresponding to the peak with a preset reference voltage.

[0079] Here, the reference voltage may be preset to reflect the state of the battery. Alternatively, the reference voltage may be preset to a predetermined voltage value (e.g., 4 V).

[0080] The following description assumes that the reference voltage is preset to 4 V. For convenience of explanation, a specific example of setting the reference voltage to reflect the battery's status is described below.

[0081] For example, the voltage comparison unit (120) can compare the magnitude of the peak voltage and the reference voltage. Specifically, the voltage comparison unit (120) can determine whether the peak voltage is greater than or equal to the reference voltage. Here, the peak voltage being greater than or equal to the reference voltage means that the voltage corresponding to at least one peak among the plurality of peaks is greater than or equal to the reference voltage. In other words, the voltage comparison unit (120) can determine whether the peak voltage is less than or equal to the reference voltage. Here, the peak voltage being less than or equal to the reference voltage means that the voltages corresponding to each of the plurality of peaks are all less than the reference voltage.

[0082] In the embodiment of FIG. 5, the peak voltage corresponding to peak (pk1) is 3.48 V, the peak voltage corresponding to peak (pk2) is 3.57 V, the peak voltage corresponding to peak (pk3) is 3.65 V, the peak voltage corresponding to peak (pk4) is 3.86 V, and the peak voltage corresponding to peak (pk5) is 4.20 V. Comparing the magnitude of each peak voltage with the reference voltage, the peak voltage (3.48 V) corresponding to peak (pk1), the peak voltage (3.57 V) corresponding to peak (pk2), the peak voltage (3.65 V) corresponding to peak (pk3), and the peak voltage (3.86 V) corresponding to peak (pk4) are less than the reference voltage (4 V). In addition, the peak voltage (4.2 V) corresponding to peak (pk5) is greater than or equal to the reference voltage (4 V). Since the voltage corresponding to at least one peak (pk5) among multiple peaks (pk1, pk2, pk3, pk4, pk5) is higher than the reference voltage, the voltage comparison unit (120) can determine that the peak voltage is higher than the reference voltage.

[0083] The measurement resistance determination step (S400) is a step of determining the resistance for a predetermined time from the start of discharge by discharging the battery as the measurement resistance, and can be performed by the measurement value determination unit (130).

[0084] Specifically, the measurement value determination unit (130) can determine the resistance change amount for a predetermined period of time from the time point at which the next discharge cycle starts after the charging cycle in which the differential profile (DP) is obtained is completed, as the measured resistance.

[0085] More specifically, the battery can be charged until the voltage (or SOC) reaches a preset charge termination voltage (or preset charge termination SOC). Then, the measurement value determination unit (130) can calculate the resistance of the battery based on the voltage change amount and discharge current from the start of the discharge cycle until a predetermined time elapses after the charge cycle is completed.

[0086] For example, it is assumed that the discharge current is Id, the discharge start voltage is Vi, and the voltage after a predetermined time has passed since the start of the discharge is Vf. In this case, the measurement value determination unit (130) can calculate the measured resistance by calculating the formula “(Vi-Vf)÷Id” using Ohm's law. In addition, the predetermined time here may be a time set in advance experimentally or theoretically. For example, the predetermined time may be set in advance to 0, 1 second, 1 second, or 60 seconds.

[0087] The diagnostic resistance determination step (S500) is a step of determining the diagnostic resistance of the battery based on the measured resistance according to the comparison result of the voltage comparison step (S300), and may be performed by the diagnostic resistance determination unit (140). The diagnostic resistance determination step (S500) may include a measured resistance correction step (S510), a step of determining the corrected measured resistance as the diagnostic resistance (S520), and a step of determining the measured resistance as the diagnostic resistance (S530).

[0088] If the peak voltage is less than the reference voltage, the diagnostic resistance determination unit (140) can determine the measured resistance as the diagnostic resistance without compensating for the measured resistance. Conversely, if the peak voltage is greater than the reference voltage, the diagnostic resistance determination unit (140) can compensate for the measured resistance and determine the compensated measured resistance as the diagnostic resistance.

[0089] Referring to FIG. 3, in step S300, it may be determined whether the peak voltage is greater than or equal to the reference voltage. If the result of step S300 is YES, step S410 may be performed. If the result of step S300 is NO, step S430 may be performed.

[0090] Step S410 is a step of determining the voltage at the start of discharge as the measurement voltage, and can be performed by the measurement value determination unit (130).

[0091] That is, the measurement resistance determination step (S400) may further include a measurement voltage determination step (S410) that determines the voltage at the start of discharge as the measurement voltage if the peak voltage is higher than the reference voltage.

[0092] Specifically, the measurement value determination unit (130) can determine the voltage at the point in time when the next discharge cycle begins after the charging cycle in which the differential profile (DP) is obtained ends as the measurement voltage.

[0093] More specifically, the battery can be charged until the voltage (or SOC) reaches a preset charge termination voltage (or preset charge termination SOC). Then, the measurement value determination unit (130) can determine the voltage at the start of the discharge cycle as the measured voltage after the charge cycle is completed.

[0094] Step S420 is a step for determining the measured resistance, and can be performed by the measured value determination unit (130). Meanwhile, steps S420 and S430 are the same steps for determining the measured resistance, but are illustrated separately in FIG. 3 for convenience of explanation.

[0095] Step S510 may be performed after the measurement resistance determination step (S420). Step S510 is a step for correcting the measurement resistance and may be performed by the diagnostic resistance determination unit (140).

[0096] Specifically, the diagnostic resistance determination unit (140) can correct the measured resistance based on the measured voltage, peak voltage, and preset resistance profile.

[0097] FIG. 6 is a diagram schematically illustrating a resistance profile (RP) according to one embodiment of the present invention.

[0098] In the embodiment of FIG. 6, the horizontal axis (X-axis) represents voltage (V), and the vertical axis (Y-axis) represents resistance (Ω).

[0099] A resistance profile (RP) may be a profile that is preset to correspond to a battery and represents a corresponding relationship between voltage and resistance.

[0100] Here, voltage can refer to open circuit voltage (OCV). Resistance can be calculated based on the voltage change when a pulse signal is applied to the battery. For example, it can refer to the voltage change recorded for 0.1 second when a pulse signal (e.g., 0.5C C-rate) is applied and the resistance calculated based on Ohm's law.

[0101] For example, a resistance profile (RP) may be preset to represent the relationship between voltage and resistance measured during the charging process of a preset reference battery. The reference battery may refer to a battery designed with the same specifications as the battery being the subject of the present invention.

[0102] As another example, a resistance profile (RP) can be preset to represent a correspondence between voltage and resistance measured during a charging process when the battery is in the Beginning of Life (BoL) state.

[0103] For convenience of explanation, a specific embodiment in which the diagnostic resistance determination unit (140) corrects the measured resistance is described below.

[0104] Step S520 is a step of determining the corrected measurement resistance as a diagnostic resistance, which can be performed by the diagnostic resistance determination unit (140).

[0105] Step S530 may be performed after the measurement resistance determination step (S430). Step S530 is a step of determining the measurement resistance as the diagnostic resistance, and may be performed by the diagnostic resistance determination unit (140).

[0106] A battery information generation method according to one embodiment of the present invention can more accurately determine diagnostic resistance by determining whether or not to correct measured resistance through voltage comparison based on a differential profile. That is, the diagnostic resistance can be determined differently depending on the type of battery (e.g., high-nickel battery, low-nickel battery, etc.).

[0107]

[0108] Below, a specific embodiment in which the diagnostic resistance determination unit (140) corrects the measured resistance in step S510 is described in more detail.

[0109] FIG. 4 is a flowchart illustrating in more detail the measurement resistance correction step (S510) of the battery information generation method according to one embodiment of the present invention.

[0110] Referring to FIG. 4, step S510 may include a first value calculation step (S511), a second value calculation step (S512), a third value calculation step (S513), and a step of correcting the measured resistance (S514).

[0111] Step S511 is a step of calculating a first value based on the measured voltage and the target voltage, and can be performed by the diagnostic resistance determination unit (140) after step S420.

[0112] Here, the target voltage can be determined as a peak voltage that is higher than the reference voltage. Specifically, since step S510 is performed when the peak voltage is higher than the reference voltage, if only one peak is detected in the peak detection step (S200), the voltage corresponding to that peak can be determined as the target voltage. If multiple peaks are detected in the peak detection step (S200), the voltage of a peak among the multiple peaks whose corresponding voltage is higher than the reference voltage can be determined as the target voltage.

[0113] Here, it is assumed that there are multiple target peaks among the multiple peaks whose corresponding voltages are higher than the reference voltage. In this case, preferably, the voltage corresponding to the largest differential capacitance among the differential capacitances of the multiple target peaks can be determined as the target voltage.

[0114] Specifically, the diagnostic resistance determination unit (140) can calculate the difference between the measured voltage and the target voltage as the first value.

[0115] In the embodiment of Fig. 5, the voltage (4.2 V) of a peak (pk5) whose corresponding voltage among multiple peaks (pk1, pk2, pk3, pk4, pk5) is higher than the reference voltage (4 V) is the target voltage (V t ) can be determined. The measured voltage is V m Assuming that, the first value is the measurement voltage (V m ) and target voltage (V t ) is the difference between (V m -V t ) can be expressed as.

[0116] Step S512 is a step of calculating a second value based on the target voltage and resistance profile (RP), which can be performed by the diagnostic resistance determination unit (140).

[0117] Specifically, the diagnostic resistance determination unit (140) can determine the rate of change of resistance with respect to voltage in the target voltage section (TS) of the resistance profile (RP) as the second value.

[0118] The target voltage range (TS) is the target voltage (V t ) can be a voltage range greater than or equal to TS. That is, the lower limit of the target voltage range (TS) is the target voltage (V t ) and the upper limit can be set as the upper limit of the resistance profile.

[0119] In the embodiment of Fig. 6, the target voltage (V t ) is 4.2 V, and the upper limit of the resistance profile (RP) is 4.4 V, so the target voltage range (TS) can be set to a voltage range of 4.2 V to 4.4 V.

[0120] For example, the second value may be set as the slope of a function obtained by linearly approximating a function representing the correspondence between the voltage included in the target voltage range (TS) and the resistance corresponding to that voltage. That is, the slope when the resistance is expressed as a linear function of the voltage may be set as the second value.

[0121] As another example, the second value may be set to the average rate of change of resistance with respect to voltage over the target voltage range (TS).

[0122] In the embodiment of FIG. 6, the average rate of change (i.e., (6-0.5)÷(4.4-4.2)=27.5) based on the lower limit voltage (or starting voltage, e.g., 4.2 V), the upper limit voltage (or ending voltage, e.g., 4.4 V), the resistance corresponding to the lower limit voltage (e.g., 0.5 Ω) and the resistance corresponding to the upper limit voltage (e.g., 6 Ω) of the target voltage range (TS) can be set as the second value.

[0123] As another example, the second value is the target voltage (Vt) and the target voltage (V) of the target voltage interval (TS). t ) can be set to the instantaneous rate of change in resistance corresponding to the resistance.

[0124] In the embodiment of Fig. 6, the target voltage (V t , e.g., 4.2 V) and the instantaneous rate of change in resistance corresponding to the target voltage (e.g., 0.5 Ω) can be set to a second value.

[0125] Preferably, the second value can be set to the slope of a linear approximation function for the target voltage interval (TS).

[0126] Step S513 is a step of calculating a third value based on the first value and the second value, and can be performed by the diagnostic resistance determination unit (140).

[0127] Specifically, the diagnostic resistance determination unit (140) can multiply the first value and the second value to produce a third value. Here, the third value is a constant for correcting the measured resistance.

[0128] Step S514 is a step of calculating a corrected measurement resistance based on the third value and the measurement resistance, which can be performed by the diagnostic resistance determination unit (140).

[0129] Specifically, the diagnostic resistance determination unit (140) can calculate a corrected measured resistance by adding the measured resistance and the third value.

[0130] For example, the compensated measured resistance can be calculated using Equation 1 below.

[0131] [Formula 1]

[0132]

[0133] Here, R calib represents the corrected measured resistance, and R m represents the measured resistance. V m represents the measured voltage, V t represents the target voltage, and a represents the rate of change of resistance with respect to voltage in the target voltage range.

[0134] Based on the observation that the internal resistance of a battery increases as it degrades, measured resistance has traditionally been used as a degradation indicator. That is, the resistance calculated based on the voltage change over a given period of time from the start of discharge to the end of charging was used as a degradation indicator.

[0135] However, as a battery degrades, the overvoltage due to polarization (e.g., ohmic polarization, activation polarization, concentration polarization, etc.) increases, so the measured voltage actually gradually decreases. Furthermore, the measured resistance also decreases due to the decrease in measured voltage. Therefore, to more accurately calculate the resistance as a deterioration indicator, it is necessary to compensate for the measured resistance by taking the decreased measured voltage into account.

[0136] A battery information generation method according to one embodiment of the present invention can more accurately determine diagnostic resistance by considering changes in voltage during resistance measurement when determining diagnostic resistance as a degradation indicator. In other words, the diagnostic resistance can be more accurately determined by considering the decrease in resistance due to a decrease in measured voltage caused by battery degradation.

[0137]

[0138] Below, a specific embodiment of setting a reference voltage reflecting the state of the battery is described.

[0139] For example, the reference voltage may be set considering the negative electrode plateau section of the battery. Specifically, the reference voltage may be set to a voltage corresponding to the lower limit capacity of the negative electrode plateau section in the battery profile. That is, the reference voltage and the lower limit capacity of the negative electrode plateau section in the battery profile may exhibit a corresponding relationship.

[0140] In general, it is known that in the high-capacity region, the anode is the dominant reactant, while the cathode participates relatively less in the reaction. Due to the different reaction rates of the anode and cathode, the capacity region where the voltage change relative to the capacity is minimal can be referred to as the cathode plateau region.

[0141] The cathode plateau region may refer to a capacity region where the voltage change of the cathode is minimal as the capacity of the cathode increases. In other words, a capacity region where the voltage change relative to the capacity is below a certain level may be preset as the cathode plateau region.

[0142] In one embodiment, the cathode plateau region can be set as a capacity region in which the rate of change of voltage with respect to capacity in the reference cathode profile is less than or equal to a preset reference ratio.

[0143] Here, the reference negative electrode profile may be a profile indicating the correspondence between the capacity and voltage of a reference negative electrode preset to correspond to the negative electrode of a battery. For example, the reference negative electrode may be the negative electrode of a coin half-cell or a three-electrode cell.

[0144] In another embodiment, the negative plateau region may be set to a capacity region greater than or equal to the capacity of a reference peak included in the reference differential profile. That is, the capacity of the reference peak may be set as the lower limit of the negative plateau region.

[0145] The reference peak may be set as a peak located in a high-capacity region greater than the minimum point of the corresponding differential voltage in the reference differential profile. In other words, the capacity of the reference peak may be greater than or equal to the capacity corresponding to the lowest differential voltage in the reference differential profile.

[0146] A reference differential profile may be a profile that represents the corresponding relationship between the capacity of a battery and the differential voltage.

[0147] Here, the differential voltage represents the instantaneous rate of change of voltage with respect to the capacity. In other words, the differential voltage can be expressed as 'dV / dQ' as the value obtained by differentiating the voltage with respect to the capacity.

[0148] The reference differential profile can be obtained by differentiating the battery profile, which is a profile representing the relationship between voltage (V) and capacity (Q) while the battery is being charged, with respect to the capacity. In other words, the battery profile is obtained during the battery charging process, and the reference differential profile can be obtained from the battery profile.

[0149] The profile acquisition unit (110) may be configured to acquire a reference differential profile. For example, the profile acquisition unit (110) may directly receive the reference differential profile of the battery from an external source. 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 directly generate a reference differential profile based on the received battery information. As another example, the profile acquisition unit (110) may measure the voltage and current of the battery and calculate the capacity. Furthermore, the profile acquisition unit (110) may generate a reference differential profile based on the voltage and capacity of the battery.

[0150] In another embodiment, the reference peak may be set to a peak located in a predetermined capacity interval in the reference differential profile.

[0151] A battery information generation method according to one embodiment of the present invention sets a reference voltage by considering the state of the battery, so that a diagnostic resistance can be determined more accurately.

[0152]

[0153] Meanwhile, the profile acquisition unit (110), voltage comparison unit (120), measurement value determination unit (130), and diagnostic resistance determination unit (140) provided in the battery information generation 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), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140) 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), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140). The above memory may be located inside or outside the profile acquisition unit (110), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140), and may be connected to the profile acquisition unit (110), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140) by various well-known means.

[0154] In addition, the battery information generation device (100) may further include a storage unit (150). The storage unit (150) may store data or programs required for each component of the battery information generation device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (150) is not particularly limited in type as long as it is a known information storage means known to be able to record, erase, update, and read data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (150) may store program codes defining processes executable by the profile acquisition unit (110), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140).

[0155] Specifically, the storage unit (150) can store information necessary for the profile acquisition unit (110), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140) to generate information about the battery. For example, the storage unit (150) can store a reference voltage, a resistance profile (RP), a reference cathode profile, and a reference ratio. In addition, the profile acquisition unit (110), the voltage comparison unit (120), the measurement value determination unit (130), and the diagnostic resistance determination unit (140) can access the storage unit (150) to obtain information necessary for diagnosing the state of the battery.

[0156]

[0157] The battery information generation 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 information generation device (100) described above. In this configuration, at least some of the components of the battery information generation device (100) can be implemented by supplementing or adding the functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), voltage comparison unit (120), measurement value determination unit (130), diagnostic resistance determination unit (140), and storage unit (150) of the battery information generation device (100) can be implemented as components of the BMS.

[0158] Additionally, the battery information generation device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery information generation 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.

[0159] FIG. 7 is a drawing showing an exemplary configuration of a battery pack (10) according to another embodiment of the present invention.

[0160] 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).

[0161] 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).

[0162] 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.

[0163] An external device (not shown) may have one end connected to the positive terminal (P+) of the battery pack (10) and the other end connected to the negative terminal (P-) of the battery pack (10). Accordingly, 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.

[0164] For example, the external device may be a charger or a load such as a motor of an electric vehicle that is powered by a battery (11).

[0165]

[0166] 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.

[0167] 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.

[0168] 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.

[0169]

[0170] [Explanation of symbols]

[0171] 10: Battery pack

[0172] 11: Battery

[0173] 12: Measurement section

[0174] 100: Battery information generation device

[0175] 110: Profile acquisition section

[0176] 120: Voltage comparison unit

[0177] 130: Measurement value determination unit

[0178] 140: Diagnostic resistance determination unit

[0179] 150: Storage

Claims

1. A profile acquisition step for acquiring a differential profile indicating a correspondence between the voltage and differential capacity of a battery; A peak detection step for detecting a peak in the above differential profile; A voltage comparison step for comparing a peak voltage corresponding to the above peak with a preset reference voltage; A measurement resistance determination step for determining the resistance for a predetermined time from the start of discharge by discharging the above battery; and A battery information generation method characterized by including a diagnostic resistance determination step for determining the diagnostic resistance of the battery based on the measured resistance according to the comparison result of the voltage comparison step.

2. In paragraph 1, The above diagnostic resistance determination step is: A battery information generation method characterized by comprising a step of determining the measured resistance as the diagnostic resistance if the peak voltage is less than the reference voltage.

3. In paragraph 1, The above measurement resistance determination step is: A battery information generation method characterized in that it further includes a measurement voltage determination step of determining the voltage at the discharge start point as the measurement voltage if the peak voltage is higher than the reference voltage.

4. In paragraph 3, The above diagnostic resistance determination step is: A measurement resistance correction step for correcting the measurement resistance based on the measurement voltage, the peak voltage, and the preset resistance profile; and comprising a step of determining the corrected measurement resistance as the diagnostic resistance; The above resistance profile is, A method for generating battery information, characterized in that the battery information is preset to correspond to the battery and is a profile indicating a correspondence relationship between voltage and resistance.

5. In paragraph 4, The above measurement resistance correction step is, A step of calculating a first value based on the above measurement voltage and target voltage; A step of calculating a second value based on the target voltage and the resistance profile; A step of calculating a third value based on the first value and the second value; and A step of calculating the corrected measurement resistance based on the third value and the measurement resistance, The above target voltage is, A battery information generation method characterized in that the voltage is determined to be higher than the reference voltage among the above peak voltages.

6. In paragraph 5, The above first value is, A battery information generation method characterized by being the difference between the measured voltage and the target voltage.

7. In paragraph 5, The above second value is, The rate of change of the resistance for the voltage in the target voltage range of the resistance profile, The above target voltage range is: A battery information generation method characterized in that the voltage range is higher than the target voltage.

8. In paragraph 5, The third value above is, A battery information generation method characterized in that the value is obtained by multiplying the first value by the second value.

9. In paragraph 5, The above corrected measured resistance is, A battery information generation method characterized in that the third value is added to the measured resistance.

10. A profile acquisition unit that acquires a differential profile indicating a correspondence between the voltage and differential capacity of the battery; A voltage comparison unit that detects a peak in the above differential profile and compares a peak voltage corresponding to the peak with a preset reference voltage; A measurement value determination unit that determines the resistance for a predetermined time from the start of discharge by discharging the above battery as the measured resistance; and A battery information generation device characterized by including a diagnostic resistance determination unit that determines the diagnostic resistance of the battery based on the measured resistance according to the comparison result.

11. In paragraph 10, The above diagnostic resistance determination unit is, A battery information generation device characterized in that, if the peak voltage is less than the reference voltage, the measurement resistance is determined as the diagnostic resistance.

12. In paragraph 10, The above measurement value determination unit, A battery information generation device characterized in that, if the peak voltage is higher than the reference voltage, the voltage at the start of the discharge is determined as the measured voltage.

13. In paragraph 12, The above diagnostic resistance determination unit is, Based on the above measurement voltage, the peak voltage and the preset resistance profile, the measurement resistance is corrected, and the corrected measurement resistance is determined as the diagnostic resistance, The above resistance profile is, A battery information generation device characterized by a profile that is preset to correspond to the above battery and represents a correspondence relationship between voltage and resistance.

14. In paragraph 13, The above diagnostic resistance determination unit is, Calculating a first value based on the measured voltage and the target voltage, calculating a second value based on the target voltage and the resistance profile, calculating a third value based on the first value and the second value, and calculating the corrected measured resistance based on the third value and the measured resistance. The above target voltage is, A battery information generation device characterized in that the voltage is determined to be higher than the reference voltage among the above peak voltages.

15. A battery pack comprising a battery information generating device according to any one of claims 10 to 14.

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