Battery diagnosis apparatus and method

Abstract

A battery diagnosis method, according to an embodiment of the present invention, may comprise the steps of: collecting battery-related measurement values during a discharge section included in each cycle of a battery charging / discharging test; setting a reference value for a state change amount of the discharge section; comparing a state change amount of the discharge section measured for each cycle with the reference value; and performing a battery diagnosis according to a result of the comparison.

Description

Battery diagnostic device and method

[0001] This application claims the benefit of Korean Patent Application No. 10-2024-0102278 filed with the Korean Intellectual Property Office on August 1, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly, to a device and method for diagnosing a lithium-sulfur battery undergoing performance testing.

[0003] Secondary batteries, which can be recharged and reused after use, are manufactured into battery modules or packs by connecting multiple battery cells in series according to the output capacity required by the device. These modules are used as power sources for various devices. With the recent advancement of portable electronic devices, electric vehicles, and large-capacity power storage systems, the need for large-capacity batteries is increasing.

[0004] Lithium-sulfur batteries are secondary batteries that use a sulfur-based material with a sulfur-sulfur bond as a positive electrode active material and lithium metal as an negative electrode active material, and have higher energy density characteristics than other types of batteries. A typical lithium-sulfur battery includes an anode formed of lithium metal or a lithium metal alloy and a cathode formed of elemental sulfur or other electroactive sulfur materials. When the state of charge (SOC) of a lithium-sulfur battery reaches a certain value (approximately 70%), the electrochemical reaction changes, and from that point on, the OCV (Open Circuit Voltage) of the lithium-sulfur battery is not proportional to the state of charge.

[0005] Meanwhile, secondary batteries undergo performance testing before shipment at the final stage of the manufacturing process. However, lithium-sulfur batteries frequently experience fires due to charging delays during performance testing. In these cases, it's difficult to predict the timing of fires and, after an ignition, accurately analyzing the cause is impossible, making it difficult to take effective preventative measures.

[0006] An object of the present invention to solve the above problems is to provide a device for diagnosing a battery, particularly a lithium-sulfur battery, during a performance test.

[0007] Another object of the present invention to solve the above problems is to provide a battery diagnosis method used by the battery diagnosis device.

[0008] A battery diagnostic device according to one embodiment of the present invention for achieving the above purpose may include at least one processor; and a memory storing at least one command executed through the processor.

[0009] The at least one command may include a command to collect battery-related measurements in a discharge section included in each cycle of a battery charge / discharge test; a command to set a reference value for a state change amount in a discharge section; a command to compare the state change amount in the discharge section measured for each cycle with the reference value; and a command to perform a battery diagnosis based on the comparison result.

[0010] Here, the battery-related measurements may include one or more of the discharge capacity, discharge OCV (Open Circuit Voltage), current, and temperature of the battery.

[0011] The reference value for the above OCV change amount can be calculated using weights that are set differently depending on the OCV of the previous cycle and the battery type.

[0012] The reference value for the above OCV change amount can also be selected through probability density function analysis of the cycle-by-cycle OCV change amount measured during a charge / discharge test process including multiple cycles.

[0013] Meanwhile, the reference value for the change in discharge capacity can be calculated using a weight that is set differently depending on the discharge capacity of the previous cycle and the battery type.

[0014] The reference value for the above discharge capacity change amount can also be selected through probability density function analysis of the discharge capacity change amount per cycle measured during a charge / discharge test process including multiple cycles.

[0015] The command to perform battery diagnosis based on the above comparison result may include a command to determine that, if the amount of change in the state of the discharge section is greater than or equal to a reference value, there is a high probability that a charging delay will occur in the charging section following the discharge section.

[0016] The at least one command may further include a command to check whether there is a change in the current and temperature used for the charge / discharge test in the cycle; and a command to stop the diagnosis if the change in the current and temperature is greater than a certain threshold.

[0017]

[0018] A battery diagnosis method according to one embodiment of the present invention for achieving the above-described other object may include: a step of collecting battery-related measurement values ​​in a discharge section included in each cycle of a battery charge / discharge test; a step of setting a reference value for a state change amount in the discharge section; a step of comparing the state change amount in the discharge section measured for each cycle with the reference value; and a step of performing a battery diagnosis based on the comparison result.

[0019] Here, the battery-related measurements may include one or more of the discharge capacity, discharge OCV (Open Circuit Voltage), current, and temperature of the battery.

[0020] The reference value for the above OCV change amount can be calculated using weights that are set differently depending on the OCV of the previous cycle and the battery type.

[0021] The reference value for the above OCV change amount can also be selected through probability density function analysis of the cycle-by-cycle OCV change amount measured during a charge / discharge test process including multiple cycles.

[0022] Meanwhile, the reference value for the change in discharge capacity can be calculated using a weight that is set differently depending on the discharge capacity of the previous cycle and the battery type.

[0023] The reference value for the above discharge capacity change amount can also be selected through probability density function analysis of the discharge capacity change amount per cycle measured during a charge / discharge test process including multiple cycles.

[0024] The step of performing battery diagnosis according to the above comparison result includes a step of determining that there is a high probability that a charging delay will occur in the charging section following the discharge section when the state change amount of the discharge section is greater than or equal to a reference value.

[0025] The above battery diagnosis method may further include a step of checking whether there is a change in the current and temperature used for the charge / discharge test in the corresponding cycle; and a step of stopping the diagnosis if the change in the current and temperature is above a certain threshold.

[0026] The above battery may include a lithium-sulfur battery.

[0027] According to the above-described embodiment of the present invention, a charging delay problem of a lithium-sulfur battery can be detected in real time and ignition can be prevented in advance.

[0028] Additionally, it is possible to diagnose problems before an incident actually occurs, enabling accurate root cause analysis of the problem.

[0029] Figure 1 is a graph to explain the charging delay problem that appears during a performance test of a lithium-sulfur battery.

[0030] FIG. 2 is a graph for explaining diagnostic parameters utilized in a battery diagnostic method according to an embodiment of the present invention.

[0031] Figure 3 is an operation flowchart of a battery diagnosis method according to an embodiment of the present invention.

[0032] FIG. 4 is a diagram for explaining a method for setting a discharge OCV change amount reference value, which is one of the battery diagnosis parameters according to an embodiment of the present invention.

[0033] Figure 5 is a block diagram of a battery diagnostic device according to the present invention.

[0034] 100: Battery Diagnostic Device

[0035] 110: Processor 120: Memory

[0036] 130: Transmitter and receiver 140: Input interface

[0037] 150: Output interface 160: Storage unit

[0038] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0039] Terms such as "first," "second," "A," and "B" may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component could be referred to as the "second component," and similarly, the second component could also be referred to as the "first component." The term "and / or" includes any combination of multiple related items listed or any one of multiple related items listed.

[0040] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0041] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0042] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0043]

[0044] Some terms used in this specification are defined as follows:

[0045] A battery cell is the smallest unit that stores electricity, and a battery module is a collection of multiple battery cells that are electrically connected.

[0046] A battery pack is a single-structure system that electrically connects module units set by a battery manufacturer and can be monitored and controlled through a BMS (Battery Management System). It can be configured to include multiple battery modules and one BPU (Battery Protection Unit) or protection device.

[0047] A battery rack refers to a battery system comprising one or more battery packs, and a battery bank refers to a large-scale battery rack system comprising multiple battery racks connected in parallel. A battery bank-level BMS can monitor and control a rack BMS (RBMS) at the battery rack level.

[0048] A battery assembly is a collection of multiple electrically connected battery cells that function as a power source when applied to a specific system or device. Here, the battery assembly may refer to a battery module, battery pack, battery rack, or battery bank, but the scope of the present invention is not limited to these entities.

[0049]

[0050] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0051]

[0052] Figure 1 is a graph to explain the charging delay problem that appears during a performance test of a lithium-sulfur battery.

[0053] Batteries are typically manufactured through electrode manufacturing, assembly, and activation / testing processes. The completed battery, which undergoes these processes, is shipped in the form of a battery pack (or battery module) comprising multiple battery cells connected in series. The battery pack is connected to a load through its positive and negative terminals, enabling charging and discharging operations. Depending on the requirements of the system in which the battery is used, the battery pack may be configured in series or parallel.

[0054] Among the various battery manufacturing processes, the activation / inspection process activates electrical energy and verifies stability. This process involves repeated aging and charging / discharging. After activation, batteries undergo a testing process to test their charge capacity and screen for defective batteries before shipment.

[0055] During the battery inspection process, charge and discharge tests may be conducted to test the battery performance, and these charge and discharge tests are typically performed by repeating charge and / or discharge cycles several times.

[0056] Typically, a constant current is applied to the battery cell under test to perform a charge / discharge test as shown in the figure for several cycles. In the graph of Fig. 1, the x-axis represents time, and the y-axis represents voltage (v). The x-axis can also represent capacity (capacity mAh). One charge / discharge cycle typically includes at least one "discharge" step and one "charge" step, and a rest step is included after each "discharge" step and each "charge" step. In the graph of Fig. 1, two discharge steps and one charge step are superimposed and displayed.

[0057] In the case of a normal cycle, the voltage of the battery cell tends to decrease over time during the discharge period using a negative current, and the voltage tends to increase as the current application time increases during the charge period using a positive current.

[0058] However, as illustrated in the charge delay cycle in Figure 1, cells with internal shorts or other problems exhibit a delayed voltage increase or even a complete voltage decrease during the charging cycle, even when current is applied. When such a charge delay occurs (the charge delay cycle), the charging time increases rapidly, potentially leading to ignition during performance testing.

[0059] The present invention is intended to solve such problems, and can detect and prevent fire caused by charging delay in real time through a diagnostic method that detects charging delay in advance before it occurs.

[0060]

[0061] FIG. 2 is a graph for explaining diagnostic parameters utilized in a battery diagnostic method according to an embodiment of the present invention.

[0062] In Fig. 2, the upper graph represents voltage values ​​(V) over time in a normal cycle and a charge delay cycle, and the lower graph represents current values ​​(A) over time in a normal cycle and a charge delay cycle. The graphs in Fig. 2 are constructed from voltage and current values ​​measured in a normal cycle and a charge delay cycle obtained through experiments.

[0063] In the upper and lower graphs of Fig. 2, each cycle includes a charge-discharge flow that sequentially follows a discharge period, a rest period, and a charge period. Here, each period of the normal cycle shown in the upper graph (voltage) and each period of the normal cycle shown in the lower graph are temporally synchronized. In addition, each period of the charge-delay cycle shown in the lower graph (current) and each period of the charge-delay cycle shown in the lower graph are also temporally synchronized.

[0064] If we first look at the graph (voltage) at the top, we can see that the voltage (OCV) measured at the last point of the resting section (0 charge current) after the discharge section in the "charge delay cycle" has a smaller value than the voltage (OCV) measured at the last point of the resting section (0 charge current) after the discharge section in the "normal cycle". In other words, if the voltage measured at the last point of the resting section (0 charge current) after the discharge section in the normal cycle is called the first OCV value, and the voltage measured at the last point of the resting section (0 charge current) after the discharge section in the charge delay cycle is called the second OCV value, we can see that the second OCV value is smaller than the first OCV value.

[0065] Additionally, examining the graph (current) at the bottom, the post-discharge rest period begins earlier in the delayed charge cycle than in the normal cycle. Considering that a battery's discharge capacity can be determined at the point of maximum discharge, i.e., the end of the discharge period, it can be seen that the discharge capacity in the delayed charge cycle is lower than in the normal cycle.

[0066] The present invention provides a method for diagnosing a charge delay in advance by using OCV and / or discharge capacity characteristics in a resting section after a discharge section located before a cycle including a charge section in which a charge delay occurs as a diagnostic parameter.

[0067]

[0068] Figure 3 is an operation flowchart of a battery diagnosis method according to an embodiment of the present invention.

[0069] Battery diagnosis according to an embodiment of the present invention can be performed during a charge / discharge test for performance testing. When a charge / discharge test for performance testing of a target battery (e.g., a battery cell) is initiated (S310), battery-related measurement values ​​are collected during the discharge section within each charge / discharge cycle (S320).

[0070] At this time, the measured values ​​may include the pattern used in the test cycle (e.g., charging current), battery temperature, and discharge section status value within each charge / discharge cycle.

[0071] More specifically, the discharge interval status value may include one or more of the OCV and discharge capacity values ​​at the end of the rest interval following the discharge interval. Here, the discharge capacity may be calculated based on the end of the discharge interval, i.e., the start of the rest interval after the discharge. More specifically, the discharge capacity may be calculated by integrating the current from the start of the discharge interval to the end of the discharge interval.

[0072] Meanwhile, the OCV and discharge capacity utilized as diagnostic parameters in the present invention can be significantly affected by changes in cycle patterns (e.g., charge / discharge current) and temperature. Therefore, in the present invention, cycle patterns and temperature can serve as diagnostic influencing factors.

[0073] Reflecting this, the present invention first checks, as a preliminary procedure, whether there is a change in the cycle pattern (charging current) or temperature, which are diagnostic influence factors, before performing a diagnosis using diagnostic parameters. That is, it is checked whether there is a change in the cycle pattern (charging current) or temperature compared to the previous cycle (S330).

[0074] If the verification result shows a significant change in the cycle pattern and temperature, i.e., a change exceeding a certain threshold (e.g., S330), the diagnosis using the diagnostic parameters is stopped or the step of collecting battery-related measurements is returned.

[0075] If there is no change in the cycle pattern and temperature compared to the previous cycle (or if there is only a small change), a diagnostic procedure (S350) using diagnostic parameters is initiated. In the diagnostic procedure (S350) according to an embodiment of the present invention, a reference value for the diagnostic parameter is set for each cycle, and the diagnostic parameter may be a reference value for the state change amount of the discharge section. That is, a reference value for the state change amount of the discharge section is set as a diagnostic parameter (S351).

[0076] Here, the state value of the discharge section may include at least one of the OCV and the discharge capacity at the last point in time of the rest section following the discharge section. In addition, the state change amount of the discharge section may include at least one of the OCV change amount compared to the previous cycle at the last point in time of the rest section following the discharge section and the discharge capacity change amount of the discharge section compared to the previous cycle.

[0077] Accordingly, according to one embodiment, the reference value for the discharge section state change amount may include the OCV change amount reference value at the last point in time of the resting section following the discharge section. According to another embodiment, the reference value for the discharge section state change amount may include the discharge capacity change amount reference value. According to yet another embodiment, the reference value for the discharge section state change amount may include the OCV change amount reference value and the discharge capacity change amount reference value at the last point in time of the resting section following the discharge section.

[0078] Here, the OCV change reference value (△OCV_) at the last point of the rest period following the discharge period th ) can be determined according to the mathematical formula 1 below.

[0079]

[0080] OCV in Equation 1 (n-1) is the OCV of the previous cycle, and β is a discharge OCV delay rate, which is a kind of weight that can be set differently depending on the type / type (e.g., capacity) of the lithium-sulfur battery. Additionally, σ is the minimum threshold related to OCV set for abnormal diagnosis.

[0081] In addition, the discharge capacity change standard in the discharge section (△Capacity_ th ) can be determined according to the mathematical formula 2 below.

[0082]

[0083] Capacity in Equation 2 (n-1) is the discharge capacity in the previous cycle, and α is a discharge capacity delay rate, which is a kind of weight that can be set differently depending on the type / type (e.g., capacity) of the lithium-sulfur battery.

[0084] Once the standard for the state change amount of the discharge section is set, the state change amount of the discharge section for each cycle is compared with the state change amount standard (S352), and the presence or absence of an abnormality in the corresponding battery is diagnosed (S360). That is, if the state change amount of the discharge section for each cycle is less than the standard (YES in S350), the corresponding cycle is determined to be a normal cycle, and the measurement value is collected by proceeding to the next cycle. Conversely, if the state change amount of the discharge section for each cycle is greater than the standard (NO in S350), the probability of a charging delay occurring in the subsequent charging section is determined to be high, so the battery is diagnosed as abnormal, and the charge / discharge test is stopped (S370).

[0085] In summary, the diagnostic procedure of the present invention according to the first embodiment relating to the diagnostic procedure using diagnostic parameters may include a step of setting a reference value for the amount of OCV change at the last point in time of the rest period following the discharge period compared to the previous cycle; and a step of comparing the amount of OCV change measured for each cycle with the reference value.

[0086] The diagnostic procedure of the present invention according to the second embodiment relating to the diagnostic procedure using diagnostic parameters may include a step of setting a reference value for the amount of change in discharge capacity in a discharge section compared to a previous cycle; and a step of comparing the amount of change in discharge capacity measured for each cycle with the reference value.

[0087] According to a third embodiment of the present invention, a diagnostic procedure using diagnostic parameters may include the steps of: setting a reference value for an OCV change amount at the end of a rest period following a discharge period compared to a previous cycle; setting a reference value for a discharge capacity change amount in a discharge period compared to a previous cycle; comparing an OCV change amount measured for each cycle with the OCV change amount reference value; and comparing a discharge capacity change amount measured for each cycle with the discharge capacity change amount reference value. In this case, if both the OCV change amount and the discharge capacity change amount are greater than their respective reference values, it may be determined that there is an abnormality in the battery cell (e.g., an internal short circuit occurs in the cell).

[0088]

[0089] FIG. 4 is a diagram for explaining a method for setting a discharge OCV change amount reference value, which is one of the battery diagnosis parameters according to an embodiment of the present invention.

[0090] Figure 4 shows a standard normal distribution graph showing the probability density function of the OCV change (delta-OCV) measured over the entire cycle (2397 cycles) included in the pre-conducted test.

[0091] As a result of normal distribution analysis on OCV change, it can be confirmed that the OCV change (delta-OCV) of a cycle in which a charging delay occurs is observed at a position (94.5%) or less with a deviation of -2σ when the average is 0.0. Therefore, the OCV change reference value according to the present invention can be set with reference to the OCV change located at a deviation of -2σ.

[0092] For example, in the graph of Fig. 4, the OCV change threshold can be derived from either the OCV change located at a deviation of -2σ or the OCV change located to the left of the deviation of -2σ. In addition, the OCV change value derived from the graph of Fig. 4 can be used as the initial value of the OCV change threshold in the diagnostic procedure of Fig. 3, or can be used to determine the discharge OCV delay rate (β) or the OCV-related minimum threshold (β) in Equation 1.

[0093] In summary, the OCV change criterion, which is one of the diagnostic parameters in the present invention, can be selected through probability density function analysis of the OCV change per cycle measured during a charge / discharge test process including multiple cycles.

[0094] Meanwhile, for the discharge capacity change amount reference value, a test and probability density function distribution curve derivation, as in Fig. 4, can be performed, and the discharge capacity change amount reference value can be set through a similar analysis process. That is, in the present invention, the discharge capacity change amount reference value, which is one of the diagnostic parameters, can be selected through probability density function analysis of the discharge capacity change amount per cycle measured during a charge / discharge test process including multiple cycles.

[0095]

[0096] Figure 5 is a block diagram of a battery diagnostic device according to the present invention.

[0097] Referring to FIG. 5, a battery diagnostic device (100) according to an embodiment of the present invention may include a processor (110); and a memory (120) that stores at least one command executed by the processor. Here, the processor may be, for example, an MCU (Micro Controller Unit) or another type of controller.

[0098] A battery diagnostic device (100) according to an embodiment of the present invention is connected to a charger / discharger that repeatedly performs multiple charging / discharging cycles according to a charging / discharging pattern, and can receive information about the charging / discharging pattern from the charger / discharger. The battery diagnostic device (100) is also connected to various measuring devices (temperature sensors, voltage sensors, etc.) and can receive measurement data related to the battery status.

[0099] Here, at least one command executed through the processor may include a command to collect battery-related measurement values ​​in a discharge section included in each cycle of a battery charge / discharge test; a command to set a reference value for a state change amount in the discharge section; a command to compare the state change amount in the discharge section measured for each cycle with the reference value; and a command to perform a battery diagnosis based on the comparison result.

[0100] Here, the battery-related measurements may include one or more of the discharge capacity, discharge OCV (Open Circuit Voltage), current, and temperature of the battery.

[0101] The reference value for the above OCV change amount can be calculated using weights that are set differently depending on the OCV of the previous cycle and the battery type.

[0102] The reference value for the above OCV change amount can also be selected through probability density function analysis of the cycle-by-cycle OCV change amount measured during a charge / discharge test process including multiple cycles.

[0103] Meanwhile, the reference value for the change in discharge capacity can be calculated using a weight that is set differently depending on the discharge capacity of the previous cycle and the battery type.

[0104] The reference value for the above discharge capacity change amount can also be selected through probability density function analysis of the discharge capacity change amount per cycle measured during a charge / discharge test process including multiple cycles.

[0105] The command to perform battery diagnosis based on the above comparison result may include a command to determine that, if the amount of change in the state of the discharge section is greater than or equal to a reference value, there is a high probability that a charging delay will occur in the charging section following the discharge section.

[0106] The at least one command may further include a command to check whether there is a change in the current and temperature used for the charge / discharge test in the cycle; and a command to stop the diagnosis if the change in the current and temperature is greater than a certain threshold.

[0107] In an embodiment according to the present invention, the battery may include a lithium-sulfur battery.

[0108] Meanwhile, the battery diagnostic device (100) according to the present invention may further include a transceiver (130), an input interface (140), an output interface (150), a storage unit (160), etc. Each component included in the battery diagnostic device (100) may be connected by a bus (170) and communicate with each other.

[0109] Additionally, the memory (120) (or storage unit) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM), and may include an Electrically Erasable Programmable Read-only Memory (EEPROM).

[0110]

[0111] According to the embodiments of the present invention described above, charging delay issues in lithium-sulfur batteries can be detected in real time, allowing for proactive prevention of fire. Furthermore, by diagnosing the problem before it actually occurs, accurate root cause analysis of the problem is possible.

[0112]

[0113] The operations of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores data readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0114] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most significant method steps may be performed by such a device.

[0115] Although the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. At least one processor; and A memory that stores at least one instruction to be executed through the processor, At least one of the above commands, A command to collect battery-related measurements during the discharge interval included in each cycle of a battery charge / discharge test; A command to set a reference value for the amount of change in the state of the discharge section; A command to compare the state change amount of the discharge section measured for each cycle with the above reference value; and A battery diagnosis device comprising a command to perform battery diagnosis based on the above comparison results.

2. In claim 1, Battery related measurements are: A battery diagnostic device comprising at least one of a discharge capacity, discharge OCV (Open Circuit Voltage), current, and temperature of a battery.

3. In claim 1, The amount of change in the state of the above discharge section is The change in OCV at the end of the rest period following the discharge period compared to the previous cycle; and A battery diagnostic device comprising at least one of: a change in discharge capacity during a discharge period compared to a previous cycle; 4. In claim 3, The reference value for the above OCV change amount is, A battery diagnostic device that calculates using weights that are set differently depending on the OCV of the previous cycle and the battery type.

5. In claim 3, The reference value for the above OCV change amount is, A battery diagnostic device selected through probability density function analysis of cycle-by-cycle OCV changes measured during a charge / discharge test process including multiple cycles.

6. In claim 3, The reference value for the above discharge capacity change amount is: A battery diagnostic device that calculates using weights that are set differently depending on the discharge capacity of the previous cycle and the battery type.

7. In claim 3, The reference value for the above discharge capacity change amount is: A battery diagnostic device selected through probability density function analysis of the amount of discharge capacity change per cycle measured during a charge / discharge test process including multiple cycles.

8. In claim 1, The command to perform battery diagnosis based on the above comparison results is: A battery diagnostic device including a command that determines that there is a high probability that a charging delay will occur in the charging section following the discharging section when the state change amount of the discharging section is greater than a reference value.

9. In claim 1, At least one of the above commands, A command to check whether there is a change in the current and temperature used in the charge / discharge test in the cycle; and A battery diagnostic device further comprising a command to stop diagnosis when the change in the current and temperature exceeds a certain threshold.

10. In claim 1, A battery diagnostic device, wherein the battery comprises a lithium-sulfur battery.

11. A step of collecting battery-related measurements during the discharge section included in each cycle of the battery charge / discharge test; A step for setting a reference value for the amount of change in the state of the discharge section; A step of comparing the state change amount of the discharge section measured for each cycle with the above reference value; and A battery diagnosis method, comprising a step of performing a battery diagnosis based on the above comparison results.

12. In claim 11, Battery related measurements are: A battery diagnosis method comprising at least one of discharge capacity, discharge OCV (Open Circuit Voltage), current, and temperature of the battery.

13. In claim 11, The amount of change in the state of the above discharge section is The change in OCV at the end of the rest period following the discharge period compared to the previous cycle; and A battery diagnosis method comprising at least one of: a change in discharge capacity during a discharge period compared to a previous cycle; 14. In claim 13, The reference value for the above OCV change amount is, A battery diagnosis method that is calculated using weights that are set differently depending on the OCV of the previous cycle and the battery type.

15. In claim 13, The reference value for the above OCV change amount is, A battery diagnosis method selected through probability density function analysis of cycle-by-cycle OCV changes measured during a charge / discharge test process including multiple cycles.

16. In claim 13, The reference value for the above discharge capacity change amount is: A battery diagnosis method calculated using weights that are set differently depending on the discharge capacity of the previous cycle and the battery type.

17. In claim 13, The reference value for the above discharge capacity change amount is: A battery diagnosis method selected through probability density function analysis of the amount of discharge capacity change per cycle measured during a charge / discharge test process including multiple cycles.

18. In claim 11, The step of performing battery diagnosis based on the above comparison results is as follows: A battery diagnosis method, comprising a step of determining that there is a high probability that a charging delay will occur in a charging section following the discharging section when the state change amount of the discharging section is greater than a reference value.

19. In claim 11, A step of checking whether there is a change in the current and temperature used in the charge / discharge test in the cycle; and A battery diagnosis method further comprising a step of stopping diagnosis when the change in the current and temperature exceeds a certain threshold.

20. In claim 11, A battery diagnosis method, wherein the battery comprises a lithium-sulfur battery.

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