Battery condition diagnosis device and method

Abstract

The battery state diagnosis device and method according to the embodiments and experimental examples of the present invention detect a cycle in which a first abnormal event occurs based on the voltage of the battery when diagnosing an abnormality in a battery undergoing charging and discharging. If a second abnormal event occurs after the detected cycle based on the OCV of the battery, the occurrence of an abnormality in the battery is determined, thereby providing a battery state diagnosis device and method with improved safety and diagnostic reliability.

Description

[Technical Field]

[0001] This application claims the benefit of the filing dates of Korean Patent Application No. 10-2023-0068267 filed with the Korean Intellectual Property Office on May 26, 2023, and Korean Patent Application No. 10-2024-0046605 filed with the Korean Intellectual Property Office on April 5, 2024, and all of the contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery state diagnosis device and method, and more particularly to a battery state diagnosis device and method for determining the occurrence of a battery abnormality based on changes in the battery voltage and OCV pattern as the battery goes through charge / discharge cycles. [Background technology]

[0003] As fossil fuels become scarce and environmental pollution becomes a growing concern, environmentally friendly alternative energy sources are becoming increasingly important. Among these alternative energy sources, the demand for rechargeable lithium secondary batteries is increasing rapidly.

[0004] As a response to environmental regulations and high oil prices, lithium secondary batteries are being applied to many industrial fields, from mobile devices to automobiles, robots, energy storage devices, etc. However, lithium secondary batteries have the risk of fire or explosion if an internal or external defect occurs, so it is important to diagnose their condition in real time.

[0005] Therefore, in the past, the voltage strength and temperature were monitored to diagnose abnormal conditions in the battery.

[0006] However, the conventional battery state diagnosis method has a drawback in that the measured value is easily affected by environmental factors. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a battery state diagnostic device.

[0008] Another object of the present invention to solve the above problems is to provide a method for diagnosing the state of a battery. [Means for solving the problem]

[0009] To achieve the above object, one embodiment of the present invention provides a battery status diagnosis device that includes a memory and a processor that executes at least one instruction in the memory, the at least one instruction including an instruction to detect a cycle in which a first abnormal event occurs, defined based on the voltage of the battery, during the progress of a charge / discharge cycle of the battery, and an instruction to determine that an abnormality has occurred in the battery if a second abnormal event defined based on the OCV (Open Circuit Voltage) of the battery occurs after the detected cycle.

[0010] In this case, the detection command may include a command to generate a virtual graph by connecting voltage values ​​at the start and end of an inspection period of a specific cycle among the charge / discharge cycles of the battery, and a command to determine whether the first abnormal event has occurred in the cycle based on a comparison value obtained by individually comparing differences in voltage values ​​over time within the inspection period of the cycle with respect to a virtual voltage value on the virtual graph.

[0011] In this case, the command to determine whether the first abnormal event has occurred may include a command to determine that the first abnormal event has occurred if the comparison value includes a positive number and a negative number.

[0012] Meanwhile, according to one embodiment, the specific cycle may be at least one charging cycle including an event in which the voltage magnitude decreases by more than a predefined threshold among charging cycles of the battery.

[0013] According to another embodiment, the specific cycle may be at least one discharge cycle of the battery that includes an event in which the magnitude of the voltage increases by more than a predefined threshold.

[0014] Meanwhile, the second abnormal event may include an event in which the magnitude of the charge OCV increases by more than a predefined threshold within N cycles after the detected cycle when the detected cycle is a charge cycle.

[0015] In addition, the second abnormal event may include an event in which, when the detected cycle is a discharge cycle, the magnitude of the discharge OCV within N cycles after the discharge cycle decreases by more than a predefined threshold.

[0016] Meanwhile, the command to determine that an abnormality has occurred in the battery may include a command to determine that an open circuit has occurred in an electrode tab of the battery.

[0017] In addition, the battery state diagnosis device may further include a command to determine that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the charging cycle in which the first abnormal event was detected.

[0018] In addition, the battery state diagnosis device may further include a command to determine that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the discharge cycle in which the first abnormal event was detected.

[0019] To achieve the above object, a battery state diagnosis method using a battery state diagnosis device according to another embodiment of the present invention includes the steps of detecting a cycle in which a first abnormal event occurs, defined based on the voltage of the battery, as the charge / discharge cycle of the battery progresses, and determining that an abnormality has occurred in the battery if a second abnormal event defined based on the OCV (Open Circuit Voltage) of the battery occurs after the detected cycle.

[0020] In this case, the detecting step may include the steps of: generating a virtual graph by connecting voltage values ​​at the start and end of an inspection period of a specific cycle among the charge / discharge cycles of the battery; and determining whether the first abnormal event has occurred in the cycle based on a comparison value obtained by individually comparing differences in voltage values ​​over time within the inspection period of the cycle with respect to the virtual voltage value on the virtual graph.

[0021] In this case, the step of determining whether the first abnormal event has occurred may include the step of determining that the first abnormal event has occurred if the comparison value includes a positive number and a negative number.

[0022] Meanwhile, according to one embodiment, the specific cycle may be at least one charging cycle including an event in which the voltage magnitude decreases by more than a predefined threshold among charging cycles of the battery.

[0023] According to another embodiment, the specific cycle may be at least one discharge cycle of the battery that includes an event in which the magnitude of the voltage increases by more than a predefined threshold.

[0024] Meanwhile, the second abnormal event may include an event in which the magnitude of the charge OCV increases by more than a predefined threshold within N cycles after the detected cycle when the detected cycle is a charge cycle.

[0025] In addition, the second abnormal event may include an event in which, when the detected cycle is a discharge cycle, the magnitude of the discharge OCV within N cycles after the discharge cycle decreases by more than a predefined threshold.

[0026] Meanwhile, the step of determining that an abnormality has occurred in the battery may include the step of determining that an open circuit has occurred in an electrode tab of the battery.

[0027] The battery state diagnosis method may further include determining that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the charging cycle in which the first abnormal event was detected.

[0028] The battery state diagnosis method may further include a step of determining that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the discharge cycle in which the first abnormal event was detected. [Effects of the Invention]

[0029] The battery state diagnosis device and method according to the embodiments and experimental examples of the present invention can provide a battery state diagnosis device and method with improved safety and diagnostic reliability by determining the occurrence of a battery abnormality based on changes in the battery voltage and OCV pattern when diagnosing an abnormality in a battery that is undergoing charging and discharging. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a block diagram of a battery system to which an embodiment of the present invention can be applied; [Figure 2] This is an image of a battery tab that has become open. [Figure 3] 1 is a block diagram of a battery state diagnosis device according to an embodiment of the present invention; [Figure 4]1 is a flowchart illustrating a battery state diagnosis method according to an embodiment of the present invention. [Figure 5] 4 is a flow chart illustrating a method for detecting a cycle in which a first abnormal event occurs in a battery state diagnosis method according to an embodiment of the present invention. FIG. [Figure 6] 1 is a graph showing measurement of charge and discharge voltages of a battery according to an experimental example of the present invention. [Figure 7] 7 is an enlarged graph of region A in FIG. 6. [Figure 8] 10 is a graph showing the voltage of a battery during a test period in a charging cycle in which an event is detected, according to a first experimental example of the present invention. [Figure 9] 9 is a table showing time-dependent comparison data calculated within the inspection section, relating to FIG. 8. [Figure 10] 10 is a graph showing the voltage of a battery in a test section in a discharge cycle in which an event is detected, according to a second experimental example of the present invention. [Figure 11] 11 is a table showing time-dependent comparison data calculated within the inspection section, relating to FIG. 10. [Figure 12] 10 is a table summarizing OCV measurement values ​​for each charge / discharge cycle of a battery according to a third experimental example of the present invention. [Figure 13] 7 is a graph showing an enlarged view of region B in FIG. 6. [Figure 14] 10 is a graph showing OCV measurements for each charge / discharge cycle of a battery according to a third experimental example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it is understood that this is not intended to limit the present invention to the specific embodiments, but rather to include all modifications, equivalents, or alternatives within the spirit and technical scope of the present invention. Like reference numerals are used to refer to like elements throughout the drawings.

[0032] Terms such as "first," "second," "A," and "B" may be used to describe various components, but the components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first component may be termed a "second component," and similarly, a second component may be termed a "first component," without departing from the scope of the present invention. The term "and / or" includes a combination of multiple associated listed items or any of multiple associated listed items.

[0033] When a component is referred to as being "coupled" or "connected" to another component, it is understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly coupled" or "directly connected" to another component, it is understood that there are no other components in between.

[0034] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise. It should be understood that in this application, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0035] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0036] FIG. 1 is a block diagram of a battery system to which an embodiment of the present invention can be applied.

[0037] Referring to FIG. 1, a battery pack or a battery module may be configured to include a plurality of battery cells connected in series. The battery cells or modules are connected to a load via positive and negative terminals to perform charging and discharging operations. The most commonly used battery cells are lithium-ion (Li-Ion) battery cells.

[0038] Such battery cells or battery modules can be connected to a Battery Management System (BMS).

[0039] A battery management system (BMS) monitors the current, voltage, and temperature of each battery cell or module under its control, and calculates the SOC (Status of Charge) based on the monitoring results to control charging and discharging. Here, the SOC (State of Charge) is the current charged state of the battery expressed as a percentage, and the SOH (State of Health) is the current deterioration state of the battery expressed as a percentage.

[0040] In this way, the battery management system (BMS) can monitor the battery cells, read the cell voltage, and transmit it to other systems connected to the battery.

[0041] In addition, the battery management system (BMS) can monitor at least one electrical component constituting the battery system and transmit the status data to other devices. To this end, the battery management system (BMS) can include a communication module for communicating with other devices included in the battery system.

[0042] The communication module of the battery management system (BMS) can communicate with other systems within the device using a Controller Area Network (CAN). In this case, the electrical components, modules, or systems within the battery management system (BMS) are connected to one another via a CAN bus. This allows the battery management system (BMS) to remotely transmit status data acquired through monitoring of the battery pack or module and at least one electrical component constituting the battery management system (BMS) to other systems using CAN communication.

[0043] Meanwhile, the Battery Management System (BMS) balances the charge of the battery cells evenly to extend the life of the battery system.

[0044] To perform such operations, the battery management system (BMS) may include various components such as fuses, current sensing elements, thermistors, switches, and balancers, and in most cases, it also includes a microcontroller unit (MCU) or a battery monitoring integrated chip (BMIC) for interlocking and controlling these components. Here, the BMIC may be an IC-type component located inside the battery management system (BMS) and measuring information such as the voltage, temperature, and current of the battery cell / module. According to an embodiment, the battery management system (BMS) may be applied to a vehicle.

[0045] Generally, a battery management system (BMS) works in conjunction with a battery protection device to shut off a charge / discharge circuit when a battery abnormality occurs. In other words, a conventional battery protection circuit shuts off a charge / discharge circuit when an abnormality occurs in any one battery cell or module, thereby limiting battery use.

[0046] The battery status diagnosis device according to an embodiment of the present invention can be embodied as being included in the configuration of a battery management system (BMS).

[0047] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

[0048] Figure 2 shows an image of a battery tab that has become open.

[0049] 2, the battery state diagnosis device may be a device that pre-diagnoses an abnormal state of a battery to prevent the occurrence of a battery fire. More specifically, the battery state diagnosis device can diagnose a disconnection of an electrode tab located inside the battery to prevent the occurrence of a fire due to a disconnection of the battery.

[0050] According to the embodiment, the battery state diagnostic device can detect a cycle in which a first abnormal event occurs by monitoring the voltage measured during the progress of charging and discharging of the battery.

[0051] Thereafter, the battery state diagnosis device monitors the pattern of the open circuit voltage (OCV) in subsequent cycles based on the detected cycle, and can determine the abnormal state of the battery based on whether or not a predefined second abnormal event occurs.

[0052] FIG. 3 is a block diagram of a battery state diagnosis device according to an embodiment of the present invention.

[0053] Referring to FIG. 3, the battery status diagnosis device 1000 may include a memory 100 , a processor 200 , a transceiver 300 , an input interface device 400 , an output interface device 500 and a storage device 600 .

[0054] According to the embodiment, the components 100, 200, 300, 400, 500, and 600 included in the battery state diagnostic device 1000 are connected by a bus 700 and can communicate with each other.

[0055] The memory 100 and the storage device 600 in the above configurations 100, 200, 300, 400, 500, and 600 may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 100 and the storage device 600 may be configured with at least one of a read only memory (ROM) and a random access memory (RAM).

[0056] Among other things, memory 100 may contain at least one instruction that is executed by processor 200 .

[0057] According to an embodiment, the at least one command includes a command to detect a cycle in which a first abnormal event occurs, defined based on the voltage of the battery, during the progress of the battery charge / discharge cycle, and a command to determine that an abnormality has occurred in the battery if a second abnormal event occurs after the detected cycle, defined based on the OCV (Open Circuit Voltage) of the battery.

[0058] The detection command may include a command to generate a virtual graph by connecting voltage values ​​at the start and end of an inspection period of a specific cycle among the charge / discharge cycles of the battery, and a command to determine whether the first abnormal event has occurred in the cycle based on a comparison value obtained by individually comparing differences in voltage values ​​over time within the inspection period of the cycle with respect to a virtual voltage value on the virtual graph.

[0059] In this case, the command to determine whether the first abnormal event has occurred may include a command to determine that the first abnormal event has occurred if the comparison value includes a positive number and a negative number.

[0060] According to one embodiment, the specific cycle may be at least one charging cycle including an event in which the magnitude of the voltage of the battery decreases by more than a predefined threshold value among the charging cycles of the battery.

[0061] According to another embodiment, the specific cycle may be at least one discharge cycle of the battery that includes an event in which the magnitude of the voltage increases by more than a predefined threshold.

[0062] Meanwhile, the second abnormal event may include an event in which the magnitude of the charge OCV increases by more than a predefined threshold within N cycles after the detected cycle when the detected cycle is a charge cycle.

[0063] In addition, the second abnormal event may include an event in which, when the detected cycle is a discharge cycle, the magnitude of the discharge OCV within N cycles after the discharge cycle decreases by more than a predefined threshold.

[0064] Meanwhile, the command to determine that an abnormality has occurred in the battery may include a command to determine that an open circuit has occurred in an electrode tab of the battery.

[0065] In addition, the battery state diagnosis device may further include a command to determine that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the charging cycle in which the first abnormal event was detected.

[0066] In addition, the battery state diagnosis device may further include a command to determine that an open electrode tab in the battery is short-circuited with another battery if the second abnormal event does not occur after the discharge cycle in which the first abnormal event was detected.

[0067] Meanwhile, the processor 200 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present invention is performed.

[0068] The processor 200 is capable of executing at least one program command stored in the memory 100, as described above.

[0069] The battery state diagnostic device according to the embodiment of the present invention has been described above. Hereinafter, a battery state diagnostic method performed by the process operations within the battery state diagnostic device will be described.

[0070] FIG. 4 is a flow chart illustrating a battery state diagnosis method according to an embodiment of the present invention.

[0071] 4, the battery state diagnosis device 1000 may monitor a voltage pattern of a battery measured during a charge / discharge cycle (S1000). Here, the battery voltage may be measured by the battery state diagnosis device 1000 or may be received in real time from an external device.

[0072] Thereafter, the battery state diagnosis device 1000 may detect a specific cycle in which a first abnormal event occurs during monitoring of the voltage of the battery (S2000). Here, the first abnormal event will be described in more detail when describing the diagnosis method of the battery state diagnosis device.

[0073] Thereafter, the battery state diagnosis device 1000 may monitor the open circuit voltage (OCV) in subsequent cycles based on the acquired specific cycle. According to an embodiment, the battery state diagnosis device 1000 may monitor whether a second abnormal event occurs with respect to the open circuit voltage (OCV) within a predefined threshold cycle performed after the specific cycle (S3000). Here, the open circuit voltage (OCV) may be a voltage value of the battery measured in an open state where no load is applied to the battery, in other words, a rest state. Furthermore, the second abnormal event may be an abnormal event predefined based on the open circuit voltage (OCV) during the progress of the charge / discharge cycle of the battery, as described above.

[0074] Thereafter, the battery state diagnostic device 1000 can determine the abnormal state of the battery based on whether or not the second abnormal event has occurred (S4000).

[0075] According to one embodiment, when the battery is undergoing a charging cycle, the battery state diagnosis device 1000 may check the charging OCV value within N cycles (threshold cycles) after the specific charging cycle in which the first abnormal event occurs. If the charging OCV value satisfies a second abnormal event, in other words, if the charging OCV value maintains a state in which it has increased by more than a predetermined threshold based on the charging OCV value at the specific charging cycle, the battery state diagnosis device 1000 may determine that an abnormal phenomenon has occurred in the battery. For example, more specifically, if the charging OCV value maintains an increase of more than a predetermined threshold within the specific threshold cycles after the charging cycle in which the first abnormal event occurs, the battery state diagnosis device 1000 may determine that an open circuit has occurred in an electrode tab located inside the battery.

[0076] According to another embodiment, when the battery is undergoing a discharge cycle, the battery state diagnosis device 1000 may check the discharge OCV value within N cycles after the specific discharge cycle in which the first abnormal event occurs. At this time, if the discharge OCV value satisfies a second abnormal event, in other words, if the discharge OCV value decreases by more than a predetermined threshold based on the discharge OCV value in the specific discharge cycle and maintains the decrease, the battery state diagnosis device 1000 may determine that an abnormal phenomenon has occurred in the battery. For example, more specifically, if the discharge OCV value decreases by more than a predetermined threshold within a predetermined threshold number of cycles after the discharge cycle in which the first abnormal event occurs and maintains the decrease, the battery state diagnosis device 1000 may determine that an open circuit has occurred in an electrode tab located inside the battery.

[0077] Meanwhile, to explain more specifically according to another embodiment, the battery state diagnosis device 1000 may determine that an abnormal phenomenon has occurred in the battery even if there is no change of a predetermined threshold value or more in the charge OCV value or the discharge OCV value within a predetermined threshold cycle based on the charge or discharge cycle in which the first abnormal event occurs. For example, based on the specific charge cycle or the specific discharge cycle in which the first abnormal event occurs, if there is no second abnormal event in the charge OCV value or the discharge OCV value within each threshold cycle, the battery state diagnosis device 1000 may determine that an open circuit has occurred in the electrode tab of the corresponding battery, causing a short circuit with another adjacent battery.

[0078] FIG. 5 is a flow chart illustrating a method for detecting a specific cycle in which a first abnormal event occurs in a battery state diagnosis method according to an embodiment of the present invention, FIG. 6 is a graph showing the measurement of the charge and discharge voltage of a battery according to an experimental example of the present invention, and FIG. 7 is a graph showing an enlarged view of area A in FIG. 6.

[0079] 5 to 7, the battery state diagnosis device 1000 can monitor the charge / discharge cycles of a battery, and thereby detect a specific cycle including an event in which the voltage difference is equal to or greater than a predefined threshold (S2100).

[0080] According to one embodiment, when a battery is undergoing a charging cycle, the battery status diagnostic device 1000 can detect a particular cycle that includes an event in which the voltage magnitude decreases by more than a predefined threshold.

[0081] According to another embodiment, when a battery is undergoing a discharge cycle, the battery status diagnosis device 1000 can detect a specific cycle including an event in which the voltage magnitude increases by more than a predefined threshold value, where the predefined threshold value can be adjusted by an administrator.

[0082] Thereafter, the battery state diagnostic device 1000 can check whether the event in the specific cycle is a first abnormal event.

[0083] More specifically, the battery state diagnosis device 1000 can set a test period (G) including the event based on the event (S2300).

[0084] According to one embodiment, the check period (G) may be set to include a predefined time period based on the time point at which the event occurs. For example, the predefined time period may be 50 seconds, and the check period (G) may be set to a total of 100 seconds, including 50 seconds before and after the time point at which the event occurs.

[0085] According to another embodiment, the check period (G) can be set at a predetermined fixed time interval from the start of the charge / discharge cycle of the battery, regardless of the occurrence of the above events.

[0086] Thereafter, the battery state diagnosis device 1000 may generate a virtual graph (L) within the test period (G) (S2500). Here, the virtual graph (L) may be a straight line graph connecting voltage data (P1) of the specific cycle at the start of the test period (G) and voltage data (P2) of the specific cycle at the end of the test period (G) based on the specific cycle in which the event was detected. In this case, the specific cycle may be a charge cycle or a discharge cycle including the event due to charging or discharging of the battery.

[0087] Thereafter, the battery state diagnostic device 1000 can use the virtual graph (L) to determine whether or not a first abnormal event has occurred in the specific cycle (S2700).

[0088] More specifically, the battery state diagnosis device 1000 may calculate comparison data by comparing the virtual data values ​​located on the virtual graph (L) with the voltage data values ​​in the specific cycle for each time point. In other words, the comparison data for each time point may be a value obtained by subtracting the voltage data in the specific cycle at the same time point from the virtual data. The battery state diagnosis device 1000 may then determine whether a first abnormal event has occurred based on the calculated comparison data. For example, the battery state diagnosis device 1000 may determine that the first abnormal event has occurred if the comparison data in the test section (G) includes both positive and negative values.

[0089] According to one embodiment, when the specific cycle is a charging cycle, the comparison data may have a positive value to a negative value in sequence.

[0090] According to another embodiment, when the specific cycle is a discharge cycle, the comparison data may have a negative value (A1) to a positive value (A2) in sequence, as shown in FIG.

[0091] FIG. 8 is a graph of the battery voltage during the test period in the charging cycle in which an event was detected, according to the first experimental example of the present invention, and FIG. 9 is a table showing the calculated comparison data by time within the test period, according to FIG. 8.

[0092] 8 and 9, a battery state diagnosis device 1000 according to a first experimental example of the present invention was used to obtain a charge cycle including an event in which a voltage change of a predetermined threshold value occurred during battery charging. Then, a check period (G) was set for the charge cycle, and the occurrence of a first abnormal event in the charge cycle was checked. In other words, the battery state diagnosis device 1000 was used to apply a check period (G) of 100 seconds to the charge cycle in which the event occurred, and to check the occurrence of a first abnormal event in the check period (G).

[0093] More specifically, the battery state diagnosis device 1000 generated a virtual graph (L1), which is a straight line graph including the voltage (P1) at the start of the inspection period (G) of 4.1417 V and the voltage (P2) at the end of the inspection period (G) of 4.1257 V, from the charging voltage data from 0 seconds to 100 seconds, which is the inspection period (G).

[0094] Thereafter, the battery state diagnosis device 1000 compared the difference with the charging voltage data within the test period (G) based on the virtual graph (L1). As a result of the comparison, it was confirmed that the comparison data in the battery charging cycle had negative values ​​from after 0 seconds (excess) to 49.1 seconds, and that the data from after 49.2 seconds to less than 100 seconds had positive values, as shown in Figure 9. As a result, the battery state diagnosis device 1000 confirmed that the comparison data in the corresponding test period (G) included both negative and positive values, and determined that a first abnormal event had occurred.

[0095] FIG. 10 is a graph of the battery voltage during the test period in the discharge cycle in which an event was detected, according to the second experimental example of the present invention, and FIG. 11 is a table showing the calculated comparison data by time within the test period, according to FIG. 10.

[0096] 10 and 11, a battery state diagnosis device 1000 according to a second experimental example of the present invention was used to obtain a discharge cycle including an event in which a voltage change of a predetermined threshold value occurred during battery discharge. Then, a test period (G) was set for the discharge cycle, and the occurrence of a first abnormal event in the discharge cycle was examined. In other words, the battery state diagnosis device 1000 was used to apply a test period (G) of 100 seconds to the discharge cycle in which the event occurred, and to diagnose the occurrence of a first abnormal event.

[0097] More specifically, as shown in FIG. 10, the battery state diagnosis device 1000 was used to generate a virtual graph (L2), which is a straight-line graph including the voltage (P1) at the start of the inspection period (G) of 3.3787 V and the voltage (P2) at the end of the inspection period (G) of 3.3720 V, from the charging voltage data from 0 seconds to 100 seconds, which is the inspection period (G).

[0098] Thereafter, the battery state diagnostic device 1000 was used to compare the difference between the virtual graph (L2) and the charging voltage data within the inspection section (G).

[0099] As a result of the comparison, it was confirmed that the comparison data in the battery discharge cycle from after 0 seconds (excess) to 59 seconds had positive values, and the data from after 59.1 seconds to less than 100 seconds had negative values, as shown in Figure 11. Therefore, the battery state diagnosis device 1000 confirmed that the comparison data in the corresponding test section (G) included both positive and negative values, and determined that a first abnormal event had occurred.

[0100] FIG. 12 is a table summarizing the OCV measurement values ​​for each charge / discharge cycle of the battery according to the third experimental example of the present invention, FIG. 13 is a graph enlarging area B of FIG. 6, and FIG. 14 is a graph showing the OCV measurement values ​​for each charge / discharge cycle of the battery according to the third experimental example of the present invention.

[0101] As shown in Figures 12 and 13, the battery state diagnosis device 1000 can monitor the change in discharge OCV (ΔOCV_EOD) within a threshold cycle, which is the cycle after the cycle in which the first abnormal event occurred.

[0102] In an experimental example, the battery state diagnosis device 1000 was used to monitor the discharge OCV change (ΔOCV_EOD) from the 86th cycle, which was the cycle at which the first abnormal event occurred, to the 87th cycle, which was the threshold cycle.

[0103] Using the battery state diagnosis device 1000, the discharge OCV in the previous cycles, before the first abnormal event occurred, was checked based on the 86th cycle. As a result, it was found that the discharge OCV was 3.39273 V at the 84th cycle and 3.39226 V at the 85th cycle, and the difference in discharge OCV was only 0.47 mV, which was not large.

[0104] Meanwhile, at cycle 86, where the first abnormal event occurred, the discharge OCV was measured at 3.35536V, a significant decrease of -36.9mV from cycle 85. Also, at cycle 87, which corresponds to the threshold cycle, the discharge OCV was measured at 3.32295V, a significant decrease of -32.4mV from cycle 86.

[0105] In other words, it was confirmed that the change in discharge OCV at cycles 86 and 87, which correspond to threshold cycles from the specific cycle, was reduced by more than 0.30 mV, which is the predefined threshold, compared to the previous cycles, cycles 85 and 86. Therefore, using the battery state diagnosis device 1000, it was determined that an electrode tab in the battery had been broken.

[0106] Thereafter, the battery state diagnosis device 1000 was used to continuously monitor the discharge OCV of the battery after the 87th cycle. As a result, the discharge OCV of the battery at the 88th cycle was measured to be 3.32896 V, which indicates an increase of 6.01 mV from the previous cycle, 87. However, as shown in Figure 14, the magnitude of the discharge OCV after the 87th cycle did not recover to the magnitude of the discharge OCV at the 85th cycle, when the battery was operating normally, indicating that an electrode tab in the battery had been broken.

[0107] The battery state diagnostic device and method according to the embodiment and experimental examples of the present invention have been described above.

[0108] The battery status diagnosis device and method according to the embodiments and experimental examples of the present invention monitor the voltage pattern due to the charge / discharge cycle of a battery to detect the cycle in which a first abnormal event occurs, and based on that cycle, determine that if a second abnormal event occurs in the open-circuit voltage value in a subsequent cycle, an open circuit will occur in the electrode tab of the battery. This allows the device and method to diagnose the abnormal state of the battery based on the battery voltage and open-circuit voltage value, enabling safe battery use.

[0109] The operations of the methods according to the embodiments and experimental examples of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. In addition, the computer-readable recording medium can be distributed among computer systems connected via a network, so that the computer-readable program or code can be stored and executed in a distributed manner.

[0110] Furthermore, the computer-readable recording medium may include a hardware device specially configured to store and execute program instructions, such as a ROM, a RAM, a flash memory, etc. The program instructions may include not only machine language code, such as that produced by a compiler, but also high-level language code that can be executed by a computer using an interpreter, etc.

[0111] Some aspects of the invention have been described in the context of an apparatus, but they may also be described in terms of a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may be described in terms of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

[0112] Although the present invention has been described above with reference to preferred embodiments and experimental examples, those skilled in the art will understand that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention as set forth in the claims below. [Explanation of symbols]

[0113] 1000: Battery condition diagnostic device 100:Memory 200: Processor 300: Transmitter / receiver 400: Input interface device 500: Output interface device 600: Storage device 700: Bus

Claims

1. memory; and a processor for executing at least one instruction in the memory; The at least one instruction: instructions for detecting a cycle in which a first abnormal event occurs, the cycle being defined based on the voltage of the battery, during the progress of a charge / discharge cycle of the battery; and The battery status diagnosis device includes an instruction for determining that an abnormality has occurred in the battery if a second abnormal event defined based on the OCV of the battery occurs after the detected cycle.

2. The detecting instruction is: A command to generate a virtual graph by connecting voltage values ​​at the start and end of a test period in a specific cycle among the charge / discharge cycles of the battery; and 2. The battery state diagnosis device according to claim 1, further comprising an instruction to determine whether the first abnormal event has occurred in the cycle based on a comparison value obtained by individually comparing differences in voltage values ​​over time within an inspection section of the cycle with respect to a virtual voltage value on the virtual graph.

3. The command to determine whether or not the first abnormal event has occurred includes: The battery state diagnosis device according to claim 2 , further comprising instructions for determining that a first abnormal event has occurred when the comparison value includes a positive number and a negative number.

4. The specific cycle is The battery state diagnosis device according to claim 2 , wherein at least one of the charging cycles of the battery includes an event in which the magnitude of the voltage decreases by more than a predefined threshold value.

5. The specific cycle is The battery state diagnosis device according to claim 2 , wherein at least one discharge cycle includes an event in which the magnitude of the voltage of the battery increases by more than a predefined threshold value.

6. The second abnormal event is If the detected cycle is a charging cycle, The battery state diagnosis device according to claim 1 , wherein the event includes an event in which the magnitude of the charge OCV within N cycles after the charge cycle increases by a predetermined threshold or more.

7. The second abnormal event is If the detected cycle is a discharge cycle, The battery state diagnosis device according to claim 1 , wherein the event includes an event in which the magnitude of the discharge OCV within N cycles after the discharge cycle decreases by a predetermined threshold or more.

8. The command to determine that an abnormality has occurred in the battery is The battery state diagnosis device according to claim 1 , further comprising a command for determining that a break has occurred in an electrode tab of the battery.

9. 6. The battery status diagnosis device according to claim 1, further comprising an instruction to determine that a broken electrode tab in the battery has shorted to another battery if the second abnormal event has not occurred since the charging cycle in which the first abnormal event was detected.

10. 6. The battery status diagnosis device according to claim 1, further comprising an instruction to determine that a broken electrode tab in the battery has short-circuited with another battery if the second abnormal event does not occur after the discharge cycle in which the first abnormal event was detected.

11. A battery state diagnosis method using a battery state diagnosis device, Detecting a cycle in which a first abnormal event occurs, the cycle being defined based on the voltage of the battery, during the progress of the charge / discharge cycle of the battery; and The method for diagnosing a battery state includes determining that an abnormality has occurred in the battery if a second abnormal event defined based on the OCV of the battery occurs after the detected cycle.

12. The detecting step includes: generating a virtual graph by connecting voltage values ​​at the start and end of an inspection period in a specific cycle among the charge / discharge cycles of the battery; and 12. The battery state diagnosis method of claim 11, further comprising: determining whether the first abnormal event has occurred in the cycle based on a comparison value obtained by individually comparing differences in voltage values ​​over time within the inspection section of the cycle with respect to a virtual voltage value on the virtual graph.

13. The step of determining whether or not a first abnormal event has occurred includes: The battery state diagnosis method according to claim 12 , further comprising the step of determining that a first abnormal event has occurred when the comparison value includes a positive number and a negative number.

14. The specific cycle is The method of claim 12, wherein at least one charging cycle of the battery includes an event in which the magnitude of the voltage decreases by more than a predefined threshold value.

15. The specific cycle is The method of claim 12, wherein at least one discharge cycle of the battery includes an event in which the magnitude of the voltage increases by more than a predefined threshold value.

16. The second abnormal event is If the detected cycle is a charging cycle, The battery state diagnosis method according to claim 11 , wherein the event includes an increase in the magnitude of the charge OCV within N cycles after the charge cycle by more than a predefined threshold.

17. The second abnormal event is If the detected cycle is a discharge cycle, The battery state diagnosis method according to claim 11 , including an event in which the magnitude of the discharge OCV within N cycles after the discharge cycle decreases by a predetermined threshold or more.

18. The abnormal state of the battery is The battery state diagnosis method according to claim 11 , further comprising disconnection of an electrode tab inside the battery.

19. 16. The battery state diagnosis method according to claim 11, further comprising the step of determining that a broken electrode tab in the battery has short-circuited with another battery when the second abnormal event has not occurred since the charging cycle in which the first abnormal event was detected.

20. 16. The battery state diagnosis method according to claim 11, further comprising the step of determining that a broken electrode tab in the battery has short-circuited with another battery when the second abnormal event has not occurred since the discharge cycle in which the first abnormal event was detected.

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