Battery diagnostic apparatus and method of operating same

Abstract

A battery diagnosis apparatus includes: an information acquisition unit for measuring a voltage and a current of a battery; and a controller for calculating a charge capacity and a discharge capacity of the battery based on the voltage and the current, and diagnosing the battery based on the charge capacity, the discharge capacity, and a difference between a charge open circuit voltage (OCV) and a discharge OCV.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0068552, filed on May 26, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments disclosed herein relate to battery diagnostic devices and methods of operating the same. Background Art

[0004] Currently commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium-ion batteries, etc. Among these batteries, compared with nickel-based batteries, lithium batteries have attracted much attention due to their advantages of free charge and discharge due to small memory effect, extremely low self-discharge rate and high energy density.

[0005] The lithium ion battery is a secondary battery that includes a positive electrode, a negative electrode, an electrolyte, and a separator, and can be charged and discharged according to the movement of lithium ions between the positive electrode and the negative electrode through the electrolyte.

[0006] When such batteries catch fire during use, reactions between chemical substances within the battery can cause serious accidents. To prevent such accidents, technologies have been developed to diagnose the battery's condition by observing whether the battery's voltage exceeds a preset voltage or temperature. However, predicting battery fire based on the battery's voltage and temperature is difficult to achieve accurately and reliably. Summary of the Invention

[0007] Technical issues

[0008] The embodiments disclosed herein are intended to provide a battery diagnostic device and an operating method thereof, wherein short circuits and lithium deposition inside a battery and the risk of fire of the battery can be diagnosed in advance.

[0009] The technical problems of the embodiments disclosed herein are not limited to the above-mentioned technical problems, and those skilled in the art in the technical field to which the present disclosure pertains will clearly understand other unmentioned technical problems through the following description.

[0010] Technical Solution

[0011] A battery diagnostic device according to one embodiment disclosed herein includes: an information obtaining unit configured to measure a voltage and a current of a battery; and a controller configured to calculate a charge capacity and a discharge capacity of the battery based on the voltage and the current, and to diagnose the battery based on the charge capacity, the discharge capacity, and a difference between a charge open circuit voltage (OCV) and a discharge OCV.

[0012] According to one embodiment, the controller may be further configured to calculate a difference between the charge capacity and the discharge capacity; and determine that the battery is abnormal when the difference between the charge capacity and the discharge capacity exceeds a first reference value.

[0013] According to one embodiment, the controller may be further configured to determine that the battery is in a dangerous state when a difference between the charge OCV and the discharge OCV is less than a second reference value.

[0014] According to one embodiment, the controller may also be configured to calculate a first difference, a second difference, and a third difference, which are differences between the charge OCV and the discharge OCV corresponding to a first cycle, a second cycle, and a third cycle sequentially consecutive among a plurality of charge and discharge cycles of the battery; and when the second difference is smaller than the first difference and the third difference is smaller than the second difference, determine that the state of the battery is a dangerous state.

[0015] According to one embodiment, the controller may be further configured to calculate a change rate of the discharge OCV; and determine that the battery state is a dangerous state when the change rate of the discharge OCV exceeds a preset range.

[0016] According to one embodiment, the controller may be further configured to calculate a rate of change of the charge OCV; and determine that the battery state is a dangerous state when the rate of change of the charge OCV exceeds a preset range.

[0017] According to one embodiment, the controller may be further configured to determine that a short circuit or lithium deposition occurs inside the battery when the rate of change of the charge OCV and the rate of change of the discharge OCV fall within a preset range.

[0018] According to one embodiment, the controller may be further configured to determine that the state of the battery is a normal state when a difference between the charge capacity and the discharge capacity is less than or equal to a first reference value.

[0019] A battery diagnosis method according to one embodiment disclosed herein includes the following steps: obtaining a charge capacity, a discharge capacity, a charge open circuit voltage (OCV), and a discharge OCV of a battery; calculating a difference between the charge capacity and the discharge capacity and a difference between the charge OCV and the discharge OCV; and determining a state of the battery based on the difference between the charge capacity and the discharge capacity and the difference between the charge OCV and the discharge OCV.

[0020] According to one embodiment, the step of determining the state of the battery may include the step of determining that the state of the battery is a normal state when a difference between the charge capacity and the discharge capacity is less than or equal to a first reference value.

[0021] According to one embodiment, the step of determining the state of the battery may include the following steps:

[0022] When the difference between the charge capacity and the discharge capacity exceeds the first reference value, it is determined whether the difference between the charge OCV and the discharge OCV is less than a second reference value.

[0023] According to one embodiment, the step of determining the state of the battery may include the step of determining that the state of the battery is a dangerous state when a difference between the charge OCV and the discharge OCV is less than a second reference value.

[0024] According to one embodiment, the step of determining the state of the battery may include the following steps: calculating a first difference, a second difference, and a third difference, which are differences between the charge OCV and the discharge OCV corresponding to a first cycle, a second cycle, and a third cycle successively consecutive among a plurality of charge and discharge cycles of the battery; and determining that the state of the battery is a dangerous state when the second difference is smaller than the first difference and the third difference is smaller than the second difference.

[0025] According to one embodiment, the step of determining the state of the battery comprises the following steps:

[0026] When the difference between the charge OCV and the discharge OCV is greater than or equal to the second reference value, it is determined that a short circuit or lithium deposition occurs inside the battery.

[0027] Details of other embodiments are included in the detailed description and accompanying drawings.

[0028] Beneficial effects

[0029] The battery diagnostic apparatus and the operating method thereof according to the embodiments disclosed herein may diagnose the state of a battery based on the charge capacity, discharge capacity, charge OCV, and discharge OCV obtained from the current and voltage in charging and discharging of the battery.

[0030] The battery diagnostic apparatus and the operating method thereof according to the embodiments disclosed herein can detect a short circuit or lithium deposition inside a battery.

[0031] The battery diagnostic apparatus and the operating method thereof according to the embodiments disclosed herein can pre-diagnose a fire risk situation of a battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a block diagram of a battery pack according to an embodiment disclosed herein.

[0033] Figure 2is a block diagram of a battery diagnostic device according to an embodiment disclosed herein.

[0034] Figure 3 FIG. 1 is a graph showing a state in which a battery diagnostic apparatus according to an embodiment disclosed herein diagnoses a short circuit or lithium deposition inside a battery.

[0035] Figure 4 FIG. 1 is a graph showing a state in which the battery diagnostic apparatus according to an embodiment disclosed herein diagnoses a fire risk condition of a battery.

[0036] Figure 5 is a graph showing a state in which the battery diagnostic apparatus according to an embodiment disclosed herein considers charge OCV and discharge OCV to diagnose a fire risk condition of a battery.

[0037] Figure 6 is a flow chart of a battery diagnosis method according to an embodiment disclosed herein.

[0038] Figure 7 It is shown in detail Figure 6 Flowchart of the operation of determining the state of a battery.

[0039] Figure 8 A computing system for executing a battery diagnostic method according to embodiments disclosed herein is shown. DETAILED DESCRIPTION

[0040] Hereinafter, the embodiments disclosed in this document will be described in detail with reference to the exemplary drawings. When adding reference numerals to the components of each drawing, it should be noted that even if the same components are indicated in different drawings, the same reference numerals are given. In addition, when describing the embodiments disclosed in this document, if it is determined that the detailed description of related known configurations or functions interferes with the understanding of the embodiments disclosed in this document, the detailed description will be omitted.

[0041] In order to describe the components of the embodiments disclosed herein, terms such as first, second, etc. may be used. These terms are only used to distinguish one component from another component, and do not limit the components to the nature, order, sequence, etc. of the components. The terms used herein, including technical terms and scientific terms, have the same meanings as those generally understood by those skilled in the art, as long as these terms are not defined differently. Generally, terms defined in general dictionaries should be interpreted as having the same meanings as the contextual meanings of the relevant technology and should not be interpreted as having ideal or exaggerated meanings unless they are clearly defined in this application.

[0042] Figure 1 is a block diagram of a battery pack according to an embodiment disclosed herein.

[0043] Reference Figure 1, schematically shows a battery control system including a battery pack 1 and an advanced controller 2 included in an advanced system according to an embodiment disclosed herein.

[0044] like Figure 1 As shown, the battery pack 1 may include one or more battery cells 11, a switching unit 14 connected in series to a first terminal side and / or a second terminal side of the battery cell 11 to control the charge / discharge current of the battery cell 11, and a battery management system 20 for managing the battery pack 1 by monitoring the voltage, current, temperature, etc. to prevent overcharging and overdischarging.

[0045] In this case, the battery pack 1 may include a plurality of battery cells 11, a sensor 12, a switch unit 14, and a battery management system 20. For example, the first terminal may be a positive (+) terminal of the battery cell 11, and the second terminal may be a negative (-) terminal.

[0046] Here, as the switch unit 14 as an element for controlling the current of the plurality of battery cells 11 for charging or discharging, for example, at least one relay, magnetic contactor, or the like may be used according to the specifications of the battery pack 1 .

[0047] The battery management system 20, which is an interface for receiving the measurement values ​​of the various parameter values ​​described above, may include a plurality of terminals and circuits connected thereto for processing the input values, etc. The battery management system 20 may control the on / off switching of the switching unit 14 (e.g., a relay, a contactor, etc.) and may be connected to the battery cells 11 to monitor the status of each battery cell 11.

[0048] The high-level controller 2 may transmit a control signal regarding the battery cells 11 to the battery management system 20. Therefore, the operation of the battery management system 20 may also be controlled based on the signal applied from the high-level controller 2.

[0049] According to one embodiment, the battery management system 20 may include Figure 2 According to another embodiment, the battery management system 20 may be different from Figure 2 The battery diagnostic device 100. That is, Figure 2 The battery diagnostic device 100 may be included in the battery pack 1 or configured as another device external to the battery pack 1. Hereinafter, for ease of description, it is assumed that the battery diagnostic device 100 includes another device external to the battery pack 1, but the present invention is not limited thereto. For example, the following operations of the battery diagnostic device 100 may be performed in various devices, such as a battery management system (BMS) in a vehicle, a server, a cloud, a charger, or a charger / discharger.

[0050] Figure 2is a block diagram of a battery diagnostic device according to an embodiment disclosed herein.

[0051] Reference Figure 2 The battery diagnostic device 100 may include a charge and discharge unit 110, an information obtaining unit 120, and a controller 130. The battery diagnostic device 100 may diagnose the state of the battery 200 using the charge and discharge unit 110, the information obtaining unit 120, and the controller 130. According to one embodiment, the battery diagnostic device 100 may be connected to the battery 200.

[0052] The charge and discharge unit 110 may charge and discharge the battery 200. The charge and discharge unit 110 may charge or discharge the battery 200 by supplying voltage or current to the battery 200.

[0053] The charge and discharge unit 110 may charge and discharge the battery 200 during a plurality of cycles. Therefore, the battery diagnostic apparatus 100 may perform a cycle test on the battery 200 by using the charge and discharge unit 110.

[0054] The information acquisition unit 120 can obtain information about the battery 200. According to one embodiment, the information acquisition unit 120 can obtain voltage information and current information of the battery 200. For example, the information acquisition unit 120 can obtain the voltage and current corresponding to each of a plurality of charge and discharge cycles. In particular, the information acquisition unit 120 can measure the voltage at the end of charging and the end of discharging included in each charge and discharge cycle, respectively. Here, the voltage at the end of charging of the battery 200 can be defined as the charge open circuit voltage (OCV). In addition, the voltage at the end of discharging of the battery 200 can be defined as the discharge OCV.

[0055] The controller 130 may calculate the charge capacity of the battery 200. The controller 130 may calculate the charge capacity corresponding to each of the plurality of cycles. According to one embodiment, the controller 130 may calculate the charge capacity of the battery 200 based on the current information and the charging time corresponding to each of the plurality of charge and discharge cycles of the battery 200.

[0056] The controller 130 may calculate the discharge capacity of the battery 200. The controller 130 may calculate the discharge capacity corresponding to each of the plurality of cycles. According to one embodiment, the controller 130 may calculate the discharge capacity of the battery 200 based on the current information and the discharge time corresponding to each of the plurality of charge and discharge cycles of the battery 200.

[0057] The controller 130 may compare the charge capacity with the discharge capacity. The controller 130 may compare the charge capacity and the discharge capacity obtained based on the same cycle among a plurality of charge and discharge cycles. According to one embodiment, the controller 130 may calculate the difference between the charge capacity and the discharge capacity to compare the charge capacity with the discharge capacity. Therefore, the controller 130 may diagnose the state of the battery 200 based on the difference between the charge capacity and the discharge capacity, but is not limited thereto. According to one embodiment, the controller 130 may calculate the ratio of the charge capacity to the discharge capacity to compare the charge capacity with the discharge capacity, and diagnose the state of the battery 200 based on the ratio of the charge capacity to the discharge capacity.

[0058] The controller 130 may compare the charge OCV with the discharge OCV. The controller 130 may compare the charge OCV and the discharge OCV corresponding to each of the plurality of charge and discharge cycles. According to one embodiment, the controller 130 may calculate the difference between the charge OCV and the discharge OCV to compare the charge OCV with the discharge OCV. Thus, the controller 130 may obtain the difference between the charge OCV and the discharge OCV corresponding to each of the plurality of charge and discharge cycles.

[0059] The controller 130 can calculate the amount of change in the charge OCV. The controller 130 can compare the charge OCV corresponding to each of a plurality of charge and discharge cycles to calculate the amount of change in the charge OCV. For example, the controller 130 can compare the first charge OCV, the second charge OCV, and the third charge OCV corresponding to the first, second, and third cycles, respectively, to calculate the amount of change in the charge OCV. The controller 130 can calculate the amount of change in the charge OCV corresponding to the second cycle based on the value obtained by subtracting the first charge OCV from the second charge OCV. The controller 130 can also calculate the amount of change in the charge OCV corresponding to the third cycle based on the value obtained by subtracting the second charge OCV from the third charge OCV.

[0060] The controller 130 may calculate the amount of change in the discharge OCV. The controller 130 may compare the discharge OCV corresponding to each of a plurality of charge and discharge cycles to calculate the amount of change in the discharge OCV. For example, the controller 130 may compare the first discharge OCV, the second discharge OCV, and the third discharge OCV corresponding to the first, second, and third consecutive cycles, respectively, to calculate the amount of change in the discharge OCV. The controller 130 may calculate the amount of change in the discharge OCV corresponding to the second cycle based on a value obtained by subtracting the first discharge OCV from the second discharge OCV. The controller 130 may also calculate the amount of change in the discharge OCV corresponding to the third cycle based on a value obtained by subtracting the second discharge OCV from the third discharge OCV.

[0061] The controller 130 may determine the state of the battery 200. The controller 130 may determine the state of the battery 200 based on the charge capacity, discharge capacity, charge OCV, and discharge OCV. Figures 3 to 5 , an operation of determining the state of the battery 200 performed by the controller 130 will be described in detail.

[0062] Figure 3 FIG. 1 is a graph showing a state in which a battery diagnostic apparatus according to an embodiment disclosed herein diagnoses a short circuit or lithium deposition inside a battery. Figure 4 FIG. 1 is a graph showing a state in which the battery diagnostic apparatus according to an embodiment disclosed herein diagnoses a fire risk condition of a battery. Figure 5 is a graph showing a state in which the battery diagnostic apparatus according to an embodiment disclosed herein considers charge OCV and discharge OCV to diagnose a fire risk condition of a battery.

[0063] Reference Figure 3 , the controller 130 may compare the charge capacity and the discharge capacity corresponding to each of the plurality of cycles with each other. For example, the controller 130 may calculate the difference between the charge capacity and the discharge capacity corresponding to each of the plurality of cycles.

[0064] The controller 130 may compare the difference between the charge capacity and the discharge capacity with a first reference value. Here, the first reference value may be a preset value for detecting a change in the discharge capacity relative to the charge capacity.

[0065] The controller 130 may compare the difference between the charge capacity and the discharge capacity with a first reference value. In this way, the controller 130 may determine whether the difference between the charge capacity and the discharge capacity exceeds the first reference value.

[0066] According to one embodiment, when there is a cycle in which the difference between the charge capacity and the discharge capacity exceeds a first reference value, the controller 130 may determine that the state of the battery 200 is abnormal.

[0067] When there is no cycle in which the difference between the charge capacity and the discharge capacity exceeds the first reference value, the controller 130 may determine that the state of the battery 200 is normal. That is, when the difference between the charge capacity and the discharge capacity in each of a plurality of charge and discharge cycles is less than or equal to the first reference value, the controller 130 may determine that the state of the battery 200 is normal.

[0068] According to one embodiment, the controller 130 may count the number of times the difference between the charge capacity and the discharge capacity exceeds a first reference value over a plurality of cycles. In this case, when the number of times the difference between the charge capacity and the discharge capacity exceeds the first reference value is a preset number or more, the controller 130 may determine that the state of the battery 200 is abnormal. Here, the preset number may be set based on the type of battery 200, the total number of charge and discharge cycles, etc. In this case, when the number of times the difference between the charge capacity and the discharge capacity exceeds the first reference value is less than the preset number, the controller 130 may determine that the state of the battery 200 is normal.

[0069] When determining that the state of battery 200 is abnormal, controller 130 may determine the detailed state of battery 220 based on the charge OCV and discharge OCV. According to one embodiment, controller 130 may calculate the difference between the charge OCV and the discharge OCV corresponding to each of a plurality of charge and discharge cycles.

[0070] When the difference between the charge OCV and the discharge OCV is greater than or equal to the second reference value, the controller 130 can determine that a short circuit or lithium deposition has occurred within the battery 200. That is, when the difference between the charge OCV and the discharge OCV corresponding to each of the plurality of cycles is greater than or equal to the second reference value, the controller 130 can determine that a short circuit or lithium deposition has occurred within the battery 200. Here, the second reference value can be set based on the difference between the charge OCV and the discharge OCV corresponding to the initial cycle among the charge and discharge cycles, the type of the battery 200 or the charger and discharger, etc.

[0071] According to one embodiment, when each of the charge OCV and the discharge OCV does not change over a plurality of charge and discharge cycles, the controller 130 may determine that a short circuit or lithium deposition occurs inside the battery 200 based on the detailed state of the battery 200 determined to be abnormal.

[0072] Reference Figure 4 , the controller 130 may diagnose the fire risk of the battery 200. When it is determined that the state of the battery 200 is abnormal, the controller 130 may determine the detailed state of the battery 220 based on the charge OCV and the discharge OCV.

[0073] According to one embodiment, when the difference between the charge capacity and the discharge capacity is less than a second reference value, the controller 130 may determine that the state of the battery 200 is a dangerous state. Here, the dangerous state may refer to a fire hazard state of the battery 200. That is, when the difference between the charge capacity and the discharge capacity is greater than or equal to the first reference value and the difference between the charge OCV and the discharge OCV is less than a second reference value, the controller 130 may determine that the state of the battery 200 is a dangerous state.

[0074] According to one embodiment, the controller 130 may calculate a first difference, a second difference, and a third difference, which are the differences between the charge OCV and the discharge OCV corresponding to the first, second, and third cycles, which are sequentially consecutive, among a plurality of charge and discharge cycles of the battery 200. The controller 130 may compare the first difference, the second difference, and the third difference with each other. Therefore, when the second difference is less than the first difference and the third difference is less than the second difference, the controller 130 may determine that the state of the battery 200 is dangerous. In other words, when the charge OCV decreases and the discharge OCV increases, the controller 130 may determine that the state of the battery 200 is dangerous.

[0075] In the drawing, the controller 130 may determine that in the battery 200, the difference between the charge OCV and the discharge OCV at the 40th cycle is greater than the difference between the charge OCV and the discharge OCV at the 39th cycle, and the difference between the charge OCV and the discharge OCV at the 41st cycle is greater than the difference between the charge OCV and the discharge OCV at the 40th cycle. Therefore, the controller 130 may determine that the state of the battery 200 that has passed the 41st charge and discharge cycle is a dangerous state.

[0076] Reference Figure 5 , the controller 130 may calculate the rate of change of the charge OCV and the rate of change of the discharge OCV. The controller 130 may determine the state of the battery 200 based on the change of the charge OCV and the change of the discharge OCV.

[0077] The controller 130 may calculate a rate of change of the charge OCV and a rate of change of the discharge OCV corresponding to each of a plurality of charge and discharge cycles. For example, the controller 130 may calculate the rate of change of the charge OCV based on a value obtained by subtracting the charge OCV of the previous cycle from the charge OCV of the corresponding cycle. The controller 130 may calculate the rate of change of the discharge OCV based on a value obtained by subtracting the discharge OCV of the previous cycle from the discharge OCV of the corresponding cycle.

[0078] For the normal battery 200 , the charge OCV and the discharge OCV are kept constant within an error range, so that a change rate of the charge OCV and a change rate of the discharge OCV according to charge and discharge cycles may be zero.

[0079] According to one embodiment, the controller 130 may determine whether the rate of change of the charge OCV exceeds a preset range. The controller 130 may also determine whether the rate of change of the discharge OCV exceeds a preset range. Here, the preset range may be set based on the type of battery 200, the type of charger / discharger, the error range, etc.

[0080] According to one embodiment, when the rate of change of the charge OCV exceeds a preset range, the controller 130 may determine that the state of the battery 200 is dangerous. When the rate of change of the charge OCV falls within the preset range, the controller 130 may determine that a short circuit or lithium deposition occurs inside the battery 200.

[0081] According to one embodiment, when the rate of change of the discharge OCV exceeds a preset range, the controller 130 may determine that the state of the battery 200 is dangerous. When the rate of change of the discharge OCV falls within the preset range, the controller 130 may determine that a short circuit or lithium deposition occurs inside the battery 200.

[0082] According to one embodiment, when both the rate of change of the charge OCV and the rate of change of the discharge OCV exceed a preset range, the controller 130 may determine that the state of the battery 200 is a dangerous state. When at least one of the rate of change of the charge OCV and the rate of change of the discharge OCV falls within a preset range, the controller 130 may determine that a short circuit or lithium deposition has occurred within the battery 200.

[0083] In the accompanying figure, the controller 130 can determine that the rate of change of the charge OCV and the rate of change of the discharge OCV are within a preset range from the 0th to the 36th cycle of the charge and discharge cycles, and that the rate of change of the charge OCV and the rate of change of the discharge OCV are outside the preset range at the 37th cycle. Therefore, the controller 130 can determine that the state of the battery 200 is dangerous at the 37th cycle among the multiple charge and discharge cycles.

[0084] In other words, when the charge OCV gradually decreases and the discharge OCV gradually increases during the repetition of the charge and discharge cycle, the controller 130 can determine that the state of the battery 200 is a dangerous state, so the rate of change of the charge OCV has a value less than or equal to the preset range, and the rate of change of the discharge OCV has a value greater than or equal to the preset range.

[0085] When the battery 200 is determined to be abnormal as a result of the diagnosis, the controller 130 may provide the user with information about the abnormal battery 200. For example, the controller 130 may provide the information about the abnormal battery 200 to a user terminal through a communication unit (not shown) and provide the information about the abnormal battery 200 through a display provided in a vehicle, a charger, or the like.

[0086] The battery diagnostic apparatus 100 can diagnose the state of the battery 200 based on the charge capacity, the discharge capacity, the charge OCV, and the discharge OCV. Therefore, the battery diagnostic apparatus 100 can improve the diagnostic accuracy of the state of the battery 200.

[0087] The battery diagnostic device 100 can perform a primary diagnosis of the battery 200's condition based on the charge capacity and discharge capacity, and a secondary diagnosis of a battery 200 determined to be in an abnormal state based on the charge OCV and discharge OCV. Thus, the battery diagnostic device 100 can identify the battery 200's condition as one of a normal state, a state where a short circuit or lithium deposition has occurred, and a fire risk state. In this way, the battery diagnostic device 100 can provide a user with a detailed understanding of the battery 200's condition, allowing them to effectively respond to abnormal battery 200 conditions.

[0088] Furthermore, since the battery diagnosis apparatus 100 notifies the user of the fire risk state of the battery 200 in advance through diagnosis of the battery 200 , the user can prevent a fire of the battery 200 .

[0089] Figure 6 is a flow chart of a method for diagnosing the battery 200 according to an embodiment disclosed herein.

[0090] Figure 6 The embodiment shown may be an example, and the order of operations according to various embodiments of the present disclosure may be different from Figure 6 The order shown in the Figure 6 For some of the operations shown in , the order of operations may be changed, or the operations may be combined.

[0091] Reference Figure 6 , the diagnostic method of the battery 200 may include the following operations: operation S100, calculating the charging capacity, discharging capacity, charging OCV and discharging OCV of the battery 200; operation S200, calculating the difference between the charging capacity and the discharging capacity and the difference between the charging OCV and the discharging OCV; and operation S300, determining the state of the battery 200.

[0092] In the following, reference will be made to Figures 1 to 5 Operations S100 to S300 are described in detail.

[0093] In operation S100 , the battery diagnostic apparatus 100 may calculate a charge capacity, a discharge capacity, a charge OCV, and a discharge OCV of the battery 200 .

[0094] The battery diagnostic device 100 can obtain information about the battery 200. According to one embodiment, the battery diagnostic device 100 can obtain voltage and current information of the battery 200. For example, the battery diagnostic device 100 can obtain the voltage and current corresponding to each of multiple charge and discharge cycles. Specifically, the battery diagnostic device 100 can measure the voltage at the end of charge and the end of discharge included in each charge and discharge cycle. Here, the voltage of the battery 200 at the end of charge can be defined as the OCV. Additionally, the voltage of the battery 200 at the end of discharge can be defined as the discharge OCV.

[0095] The battery diagnostic device 100 can calculate the charge capacity of the battery 200. The battery diagnostic device 100 can calculate the charge capacity corresponding to each of a plurality of cycles. According to one embodiment, the battery diagnostic device 100 can calculate the charge capacity of the battery 200 based on the current information and the charging time corresponding to each of a plurality of charge and discharge cycles of the battery 200.

[0096] The battery diagnostic device 100 can calculate the discharge capacity of the battery 200. The battery diagnostic device 100 can calculate the discharge capacity corresponding to each of a plurality of cycles. According to one embodiment, the battery diagnostic device 100 can calculate the discharge capacity of the battery 200 based on the current information and discharge time corresponding to each of a plurality of charge and discharge cycles of the battery 200.

[0097] In operation S200 , the battery diagnostic apparatus 100 may calculate a difference between a charge capacity and a discharge capacity and a difference between a charge OCV and a discharge OCV.

[0098] The battery diagnostic device 100 can compare the charge capacity with the discharge capacity. The battery diagnostic device 100 can compare the charge capacity and discharge capacity obtained based on the same cycle among multiple charge and discharge cycles. According to one embodiment, the battery diagnostic device 100 can calculate the difference between the charge capacity and the discharge capacity to compare the charge capacity with the discharge capacity. Therefore, the battery diagnostic device 100 can diagnose the condition of the battery 200 based on the difference between the charge capacity and the discharge capacity, but is not limited to this. According to one embodiment, the battery diagnostic device 100 can calculate the ratio of the charge capacity to the discharge capacity to compare the charge capacity with the discharge capacity, and diagnose the condition of the battery 200 based on the ratio of the charge capacity to the discharge capacity.

[0099] The battery diagnostic device 100 can compare the charge OCV with the discharge OCV. The battery diagnostic device 100 can compare the charge OCV and the discharge OCV corresponding to each of a plurality of charge and discharge cycles. According to one embodiment, the battery diagnostic device 100 can calculate the difference between the charge OCV and the discharge OCV to compare the charge OCV with the discharge OCV. Thus, the battery diagnostic device 100 can obtain the difference between the charge OCV and the discharge OCV corresponding to each of a plurality of charge and discharge cycles.

[0100] In operation S300 , the battery diagnostic apparatus 100 may determine a state of the battery 200 .

[0101] The battery diagnostic device 100 can determine the state of the battery 200 based on the charge capacity, discharge capacity, charge OCV, and discharge OCV. Figure 7 Describe in detail.

[0102] Figure 7 It is shown in detail Figure 6 Flowchart of the operation of determining the state of the battery 200 in .

[0103] In operation S310 , the battery diagnostic apparatus 100 may determine whether a difference between a charge capacity and a discharge capacity exceeds a first reference value.

[0104] The battery diagnosis apparatus 100 may compare the difference between the charge capacity and the discharge capacity with a first reference value. Here, the first reference value may be a preset value for detecting a change in the discharge capacity relative to the charge capacity.

[0105] The battery diagnostic apparatus 100 may compare the difference between the charge capacity and the discharge capacity with a first reference value, thereby determining whether the difference between the charge capacity and the discharge capacity exceeds the first reference value.

[0106] When the difference between the charge capacity and the discharge capacity exceeds the first reference value, the battery diagnostic apparatus 100 may perform operation S320. When the difference between the charge capacity and the discharge capacity is less than or equal to the first reference value, the battery diagnostic apparatus 100 may perform operation S330.

[0107] In operation S320 , the battery diagnostic apparatus 100 may determine whether a difference between the charge OCV and the discharge OCV is less than a second reference value.

[0108] When determining that the state of battery 200 is abnormal, battery diagnostic apparatus 100 may determine the detailed state of battery 220 based on the charge OCV and discharge OCV. According to one embodiment, battery diagnostic apparatus 100 may calculate the difference between the charge OCV and the discharge OCV corresponding to each of a plurality of charge and discharge cycles.

[0109] The battery diagnostic device 100 may compare the difference between the charge OCV and the discharge OCV with a second reference value. When the difference between the charge OCV and the discharge OCV is greater than or equal to the second reference value, the battery diagnostic device 100 may perform operation S340. When the difference between the charge OCV and the discharge OCV is less than the second reference value, the battery diagnostic device 100 may perform operation S350.

[0110] In operation S330, the battery diagnostic device 100 may determine that the state of the battery 200 is a normal state. According to one embodiment, in this case, the battery diagnostic device 100 may not provide a separate notification to the user, but is not limited thereto. For example, the battery diagnostic device 100 may provide a normal state notification to the user of the battery 200.

[0111] In operation S340, the battery diagnostic apparatus 100 may determine that a short circuit or lithium deposition has occurred inside the battery 200. That is, when the difference between the charge capacity and the discharge capacity exceeds a first reference value and the difference between the charge OCV and the discharge OCV is greater than or equal to a second reference value, the battery diagnostic apparatus 100 may determine that a short circuit or lithium deposition has occurred inside the battery 200.

[0112] In operation S350, the battery diagnostic apparatus 100 may determine that the state of the battery 200 is a dangerous state. That is, when the difference between the charge capacity and the discharge capacity exceeds a first reference value and the difference between the charge OCV and the discharge OCV is less than a second reference value, the battery diagnostic apparatus 100 may determine that the state of the battery 200 is a dangerous state.

[0113] In operation S360 , the battery diagnostic apparatus 100 may provide a short circuit or lithium deposition notification to a user.

[0114] In operation S370 , the battery diagnostic apparatus 100 may provide a risk status notification to the user.

[0115] Figure 8 A computing system for executing a battery diagnostic method according to embodiments disclosed herein is shown.

[0116] Reference Figure 7 , the computing system 300 according to the embodiments disclosed herein may include an MCU 310 , a memory 320 , an input / output I / F 330 , and a communication I / F 340 .

[0117] The MCU 310 can be a program that executes various programs (e.g., SOH calculation program, cell balance target determination program, etc.) stored in the memory 320, processes various data including SOC, SOH, etc. of multiple battery cells through these programs, and executes reference Figures 1 to 7 The above functions of the battery diagnostic device 100 are described as follows.

[0118] The memory 320 may store various programs related to SOH calculation of battery cells, cell balancing target determination, etc. In addition, the memory 320 may store various data of each battery cell, such as SOC data, SOH data, etc.

[0119] The memory 320 may be provided in multiple forms as needed. The memory 320 may be a volatile memory or a non-volatile memory. For the memory 320 as a volatile memory, a random access memory (RAM), a dynamic RAM (DRAM), a static RAM (SRAM), or the like may be used. For the memory 320 as a non-volatile memory, a read-only memory (ROM), a programmable ROM (PROM), an electrically alterable ROM (EAROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a flash memory, or the like may be used. The above examples of the memory 320 are merely examples and are not limited thereto.

[0120] The input / output I / F 330 may provide an interface for transmitting and receiving data by connecting an input device (not shown) such as a keyboard, a mouse, a touch screen, and an output device such as a display (not shown) to the MCU 310 .

[0121] Communication I / F 340 is a component capable of transmitting and receiving various data to and from a server, and may be any device capable of supporting wired or wireless communication. For example, programs and various data used for calculating the battery cell's state of health (SOH) or determining a balance target can be transmitted to and received from a separately provided external server via communication I / F 340.

[0122] Therefore, the battery management method according to the embodiments disclosed herein may be recorded in the memory 320 and executed by the MCU 310 .

[0123] The above description merely illustrates the technical idea of ​​the present disclosure, and various modifications and changes may be made by a person skilled in the art to which the embodiments disclosed herein pertain without departing from the essential features of the embodiments of the present disclosure.

[0124] Therefore, the embodiments disclosed herein are intended to describe rather than limit the technical spirit of the embodiments disclosed herein, and the scope of the technical spirit of the present disclosure is not limited by these embodiments disclosed herein. The scope of protection of the technical spirit disclosed herein should be interpreted by the appended claims, and all technical spirits within the same scope should be understood to be included within the scope of the present disclosure.

Claims

1. A battery diagnostic device, comprising: an information obtaining unit configured to measure a voltage and a current of a battery; as well as A controller is configured to calculate a charge capacity and a discharge capacity of the battery based on the voltage and the current, and diagnose the battery based on the charge capacity, the discharge capacity, and a difference between a charge open circuit voltage (OCV) and a discharge OCV.

2. The battery diagnostic device according to claim 1, wherein: The controller is further configured to: calculating a difference between the charge capacity and the discharge capacity; and The battery is determined to be abnormal when a difference between the charge capacity and the discharge capacity exceeds a first reference value.

3. The battery diagnostic device according to claim 2, wherein: The controller is further configured to determine that the battery is in a dangerous state when a difference between the charge OCV and the discharge OCV is less than a second reference value.

4. The battery diagnostic device according to claim 3, wherein: The controller is further configured to: calculating a first difference, a second difference, and a third difference, which are differences between the charge OCV and the discharge OCV corresponding to a first cycle, a second cycle, and a third cycle sequentially consecutive among a plurality of charge and discharge cycles of the battery; and When the second difference is smaller than the first difference and the third difference is smaller than the second difference, it is determined that the state of the battery is the dangerous state.

5. The battery diagnostic device according to claim 3, wherein: The controller is further configured to: calculating a rate of change of the discharge OCV; and When the rate of change of the discharge OCV exceeds a preset range, it is determined that the battery state is the dangerous state.

6. The battery diagnostic device according to claim 3, wherein: The controller is further configured to: Calculating the rate of change of the charging OCV; and When the rate of change of the charging OCV exceeds a preset range, it is determined that the state of the battery is the dangerous state.

7. The battery diagnostic device according to claim 2, wherein: The controller is further configured to determine that a short circuit or lithium deposition occurs inside the battery when the rate of change of the charge OCV and the rate of change of the discharge OCV fall within a preset range.

8. The battery diagnostic device according to claim 1, wherein: The controller is further configured to determine that the state of the battery is a normal state when a difference between the charge capacity and the discharge capacity is less than or equal to a first reference value.

9. A battery diagnosis method, comprising the following steps: Obtain the battery's charge capacity, discharge capacity, charge open circuit voltage (OCV), and discharge OCV; calculating a difference between the charge capacity and the discharge capacity and a difference between the charge OCV and the discharge OCV; as well as A state of the battery is determined based on a difference between the charge capacity and the discharge capacity and a difference between the charge OCV and the discharge OCV.

10. The battery diagnosis method according to claim 9, wherein: The step of determining the state of the battery includes determining that the state of the battery is a normal state when a difference between the charge capacity and the discharge capacity is less than or equal to a first reference value.

11. The battery diagnosis method according to claim 9, wherein: The step of determining the state of the battery includes determining whether a difference between the charge OCV and the discharge OCV is less than a second reference value when the difference between the charge capacity and the discharge capacity exceeds a first reference value.

12. The battery diagnosis method according to claim 11, wherein: The step of determining the state of the battery includes determining that the state of the battery is a dangerous state when a difference between the charge OCV and the discharge OCV is smaller than the second reference value.

13. The battery diagnosis method according to claim 11, wherein: The step of determining the state of the battery comprises the following steps: calculating a first difference, a second difference, and a third difference that are differences between the charge OCV and the discharge OCV corresponding to a first cycle, a second cycle, and a third cycle that are sequentially continuous among a plurality of charge and discharge cycles of the battery; and When the second difference is smaller than the first difference and the third difference is smaller than the second difference, it is determined that the state of the battery is a dangerous state.

14. The battery diagnosis method according to claim 11, wherein: The step of determining the state of the battery includes the step of determining that a short circuit or lithium deposition occurs inside the battery when a difference between the charge OCV and the discharge OCV is greater than or equal to the second reference value.

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