Discharging device and discharging method for battery, and diagnostic device and diagnostic method for battery

Abstract

The present invention relates to a discharging device and a discharging method for a battery, and a diagnostic device and a diagnostic method for a battery. The discharging method for a battery according to the present invention comprises: a step for performing a discharge of at least one battery; a step for acquiring voltage drop data of the at least one battery during the discharge; and a step for determining a state of the at least one battery on the basis of the voltage drop data, wherein it is determined that the battery is in an abnormal state caused by an overvoltage drop when an actual voltage drop of the battery is relatively faster and greater than a standard voltage drop of the battery, and the difference between the standard voltage drop and the actual voltage drop is greater than a preset threshold value.

Description

Battery discharge device, discharge method, diagnostic device, and diagnostic method

[0001] The present invention relates to battery recycling, and more specifically to an apparatus and method for evaluating and diagnosing safety for recycling batteries.

[0002] In modern society, lithium-ion batteries are widely used in various fields, including eco-friendly vehicles, energy storage systems (ESS), and portable electronic devices. While lithium-ion batteries offer many advantages due to their high energy density and efficiency, they also pose a risk of fire or explosion. In particular, degradation occurring during normal use destabilizes the internal cell structure, which can increase the risk of fire and explosion during the recycling process. Since residual energy may remain within the battery, exposure to environmental factors such as physical impact, high temperatures, or overcharging increases the likelihood of a fire. Therefore, diagnosing and eliminating these fire risks in advance is essential for the safe recycling of batteries.

[0003] In particular, the battery recycling process requires separating or crushing cells. During this stage, rapid chemical reactions can occur within the battery, potentially leading to fires or explosions. Recycling batteries requires devices and systems capable of handling them safely, and specifically, diagnostic technology is needed to conduct the recycling process without the risk of fire. While some diagnostic technologies currently exist, there is still a lack of technology capable of comprehensively diagnosing the thermal and electrical conditions within the battery and identifying abnormalities.

[0004] According to one embodiment of the present invention, the purpose is to enable safe recycling by diagnosing an abnormal condition inside the battery in advance during the battery recycling process.

[0005] A battery discharge method according to the present invention for the above-described purpose comprises: a step of performing a discharge of at least one battery; a step of obtaining voltage drop data of the at least one battery during the discharge; and a step of determining the state of the at least one battery based on the voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and greater than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

[0006] Additionally, it further includes the step of adjusting the discharge control conditions of the at least one battery based on the overvoltage drop of the at least one battery.

[0007] In addition, the adjustment of the discharge control conditions includes adjusting the discharge rate of the at least one battery based on the overvoltage drop of the at least one battery.

[0008] Additionally, the method further includes the step of identifying the type of at least one battery; the step of setting a discharge profile corresponding to the identified battery type; and the method performs the discharge of the at least one battery by applying the set discharge profile.

[0009] In addition, the adjustment of the discharge control conditions includes modifying the discharge profile based on the overvoltage drop of at least one battery.

[0010] Additionally, it further includes the step of stopping the discharge of the at least one battery based on the overvoltage drop of the at least one battery.

[0011] In addition, the above at least one battery is a waste battery module for recycling.

[0012] In addition, the error at time t between the actual measured voltage and the normal discharge voltage of the battery is expressed by the following formula.

[0013]

[0014] In the above equation, Vmodel(t) is the normal discharge voltage of the battery, Vmeasrued(t) is the actual measured voltage, and ΔVerror(t) is the error at time t between the normal discharge voltage Vmodel(t) and the actual measured voltage Vmeasrued(t).

[0015] In addition, the actual measured voltage Vmeasured(t) is expressed by the following equation.

[0016]

[0017] In the above equation, Vocv is the initial voltage at the time when the diagnosis of the battery begins, I(t) is the discharge current, Rint is the internal resistance of the battery, and ΔVpolarization is the voltage drop due to the polarization phenomenon caused by the degradation of the battery.

[0018] A battery discharge device according to the present invention for the purpose described above comprises: a battery connection part provided to connect at least one battery for discharge; a sensor provided to detect the voltage of the at least one battery; and an abnormality detection part; wherein the abnormality detection part acquires voltage drop data of the at least one battery during the discharge of the at least one battery; and determines the state of the at least one battery based on the voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and greater than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

[0019] Additionally, the device further includes a control unit configured to control the overall operation of the battery discharge device; the control unit adjusts the discharge control conditions of the at least one battery based on the overvoltage drop of the at least one battery.

[0020] In addition, the adjustment of the discharge control conditions includes adjusting the discharge rate of the at least one battery based on the overvoltage drop of the at least one battery.

[0021] Additionally, the control unit identifies the type of at least one battery; sets a discharge profile corresponding to the identified battery type; and performs the discharge of the at least one battery by applying the set discharge profile.

[0022] In addition, the adjustment of the discharge control conditions includes modifying the discharge profile based on the overvoltage drop of at least one battery.

[0023] In addition, the control unit stops the discharge of the at least one battery based on an overvoltage drop of the at least one battery.

[0024] In addition, the above at least one battery is a waste battery module for recycling.

[0025] In addition, the error at time t between the actual measured voltage and the normal discharge voltage of the battery is expressed by the following formula.

[0026]

[0027] In the above equation, Vmodel(t) is the normal discharge voltage of the battery, Vmeasrued(t) is the actual measured voltage, and ΔVerror(t) is the error at time t between the normal discharge voltage Vmodel(t) and the actual measured voltage Vmeasrued(t).

[0028] In addition, the actual measured voltage Vmeasured(t) is expressed by the following equation.

[0029]

[0030] In the above equation, Vocv is the initial voltage at the time when the diagnosis of the battery begins, I(t) is the discharge current, Rint is the internal resistance of the battery, and ΔVpolarization is the voltage drop due to the polarization phenomenon caused by the degradation of the battery.

[0031] A battery diagnostic method according to the present invention for the above-described purpose comprises: a step of performing a discharge of at least one battery; a step of obtaining voltage drop data of the at least one battery during the discharge; and a step of determining the state of the at least one battery based on the voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and greater than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

[0032] A battery diagnostic device according to the present invention for the purpose described above comprises: a battery connection part provided to connect at least one battery for discharge; a sensor provided to detect the voltage of the at least one battery; and an abnormality detection part; wherein the abnormality detection part acquires voltage drop data of the at least one battery during the discharge of the at least one battery; and determines the state of the at least one battery based on the voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and greater than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

[0033] According to one embodiment of the present invention, by diagnosing abnormal conditions inside the battery in advance, the risk of fire caused by the battery during the recycling process is reduced, and the battery can be recycled safely. Ultimately, the present invention enables stable discharge treatment of the battery during the recycling process, thereby contributing to efficient battery resource circulation in environmental and economic aspects.

[0034] Figure 1 is a diagram showing the battery recycling process.

[0035] FIG. 2 is a drawing showing a battery discharge device according to one embodiment of the present invention.

[0036] FIG. 3 is a diagram showing a battery discharge method according to one embodiment of the present invention.

[0037] Figure 4 is a diagram showing examples of voltage characteristics by type of battery.

[0038] FIG. 5 is a diagram showing examples of normal voltage drop and abnormal voltage drop of a battery detected through battery safety diagnosis according to one embodiment of the present invention.

[0039] FIG. 6 is a diagram showing the type of abnormal voltage pattern related to the voltage characteristics of the battery module (222) in the battery discharge process according to the present invention.

[0040] The embodiments described in this document and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and various modifications that may replace the embodiments and drawings of this specification may exist at the time of filing this application.

[0041] The terms used in this document are for the purpose of describing embodiments and are not intended to limit or restrict the disclosed invention.

[0042] For example, in this specification, singular expressions may include plural expressions unless the context clearly indicates otherwise.

[0043] In this document, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0044] The term "and / or" includes a combination of multiple related described components or any of the multiple related described components. For example, "A and / or B" may include only "A," only "B," or both "A and B."

[0045] Additionally, terms such as “include” or “have” are intended to express the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not exclude the additional existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] When it is said that a component is “connected,” “combined,” “supported,” or “in contact” with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0047] When it is said that a component is located “on” another component, this includes not only cases where one component is in contact with another component, but also cases where another component exists between the two components.

[0048] Meanwhile, terms such as “front,” “rear,” “left,” “right,” “top,” and “bottom” used in the following description are defined based on the drawings; however, the shape and position of each component are not limited by these terms. For example, the front side may be defined as the +X side and the rear side as the -X side. For example, based on the drawings, the right side may be defined as the +Y side and the left side as the -Y side. For example, based on the drawings, the top side may be defined as the +Z side and the bottom side as the -Z side.

[0049] In addition, terms including ordinal numbers, such as "first," "second," etc., are used to distinguish one component from another and do not limit the components.

[0050] In addition, terms such as "~part," "~unit," "~block," "~part," and "~module" may refer to a unit that processes at least one function or operation. For example, the terms may refer to at least one piece of hardware such as an FPGA (Field-Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), at least one piece of software stored in memory, or at least one process processed by a processor.

[0051] At least one of the operations to be described below may be performed by a computing device and / or an operator.

[0052] A computing device may include a general-purpose processor such as a CPU, AP, DSP (Digital Signal Processor), a graphics-dedicated processor such as a GPU, VPU (Vision Processing Unit), or an artificial intelligence-dedicated processor such as an NPU.

[0053] A computing device may include a storage medium (e.g., memory) that stores at least one instruction for performing operations to be described below, at least one artificial intelligence model, etc.

[0054] However, at least one instruction and at least one artificial intelligence model may be stored in a separate device outside the computing device (e.g., a cloud computing device), and the operations described below may be performed by a processor included in the separate device outside the computing device (e.g., a cloud computing device).

[0055] A computing device may include an output device (e.g., a display) and / or an input device (e.g., a mouse, a touch panel, etc.) for performing operations to be described below.

[0056] Identical reference numbers or reference symbols presented in the attached drawings may represent parts or components that perform substantially the same function.

[0057] The operating principle and embodiments of the present invention will be described below with reference to the attached drawings.

[0058] Figure 1 is a diagram showing the battery recycling process.

[0059] When a battery's State of Health (SoH) drops below 70%, performance characteristics such as charging speed, output, and duration deteriorate significantly. SoH is a value calculated by comparing the level of performance degradation caused by increased internal resistance to the initial performance. For example, if the capacity at the time of manufacture is 100 and the current effective capacity is 60, the SoH of that battery is 60%.

[0060] Batteries are recycled through reuse or recycling methods depending on their SoH. Batteries with an SoH of 60-70% are reused as energy storage systems (ESS) or uninterruptible power supply (UPS), while batteries with a SoH lower than that are recycled to extract rare metals such as lithium, nickel, cobalt, and manganese, which are then used to manufacture new batteries.

[0061] As shown in FIG. 1, the battery recycling process consists of two stages: a pretreatment process and a posttreatment process. In FIG. 1, reference numerals 110 to 140 represent the pretreatment process, and reference numerals 150 to 180 represent the posttreatment process.

[0062] The pretreatment process includes receiving (110), discharge / deactivation process (120), sorting process after dismantling (130), crushing / grinding process (140), etc.

[0063] In the discharge and deactivation process (120), the risk of explosion is eliminated by forcibly discharging the remaining energy of the battery to deactivate it. Discharge methods include saltwater discharge, electronic load discharge, and dry recovery discharge. Saltwater discharge is a method of discharging by immersing the battery in saltwater and allowing current to flow between the positive and negative electrodes. Electronic load discharge is a method of discharging by applying a load to the battery using a load device with a settable resistance value. The present invention relates to a battery safety diagnosis in an electronic load discharge method discharge process. Dry recovery discharge is a method of recovering and reusing energy consumed during the battery discharge process.

[0064] The sorting process (130) after dismantling is a step of separating the dismantled batteries according to their physical properties by material, generally based on particle size, density, magnetic properties, etc. Through this process, metals such as iron, copper, and aluminum are separated.

[0065] The crushing and grinding process (140) is a process of crushing and grinding batteries to produce black powder, and mainly two methods are used: dry and wet.

[0066] The post-processing process includes a dry process (150) and a wet process (160). The post-processing process is a process of extracting valuable metals such as lithium, nickel, and cobalt by refining the black powder obtained from the pre-processing process. This process is broadly divided into a dry process (150) and a wet process (160). In the dry process (150), the black powder is heated to a high temperature to reduce the metal. In the wet process (160), valuable metals such as lithium, nickel, and cobalt are recovered through processes such as leaching, solvent extraction, and crystallization. The dry process (150) and the wet process (160) can be operated selectively as needed.

[0067] FIG. 2 is a drawing showing a battery discharge device according to an embodiment of the present invention. The battery discharge device (200) according to an embodiment of the present invention shown in FIG. 2 includes a multi-channel battery connection module jig (212), a discharge profile setting module (214), a receiver (216), an abnormality detection evaluation module (218), an automatic discharge and short circuit module (220), a sensor module (224), and an integrated control module (226).

[0068] The multi-channel battery connection module jig (212) is a device that allows multiple battery modules (222) to be connected and discharged simultaneously, enabling efficient discharge and diagnosis of multiple battery modules (222).

[0069] The discharge profile setting module (214) identifies each type of battery module (222) and applies a preset discharge profile suitable for the type of battery module (222) to cause the battery module (222) to discharge.

[0070] A discharge profile is data indicating how voltage and current change over time while the battery is being discharged. In other words, the discharge profile provides important information that can be used to analyze the state of the battery module (222) during the discharge process. Key elements of a discharge profile may include voltage and current, a discharge curve, depth of discharge (DoD), and discharge time. When the battery module (222) is discharged, the voltage of the battery module (222) gradually decreases over time. In the discharge profile, voltage is an indicator that can be used to determine how well the battery module (222) is being discharged or how evenly the discharge is occurring. While the battery module (222) is being discharged, the current can change as required by the battery discharge device (200). It may be discharged at a constant current, or there may be variations in current depending on the equipment used. Current is an important indicator representing the discharge characteristics of the battery module (222). A discharge curve represents the relationship between voltage and time, or current and time, while the battery module (222) is being discharged, and is used to analyze the lifespan of the battery module (222). The depth of discharge (DoD) is an indicator of how much the battery module (222) has been discharged; for example, a depth of discharge of 80% means that 80% of the capacity of the battery module (222) has been used. The deeper the depth of discharge, the shorter the lifespan of the battery module (222). The discharge time is the time it takes for the battery module (222) to be completely discharged, and a longer discharge time usually means a higher capacity. Through such a discharge profile, the lifespan, performance, and stability of the battery module (222) can be diagnosed.

[0071] The sensor module (224) is configured to detect data such as voltage, current, temperature, and humidity in real time during the discharge of the battery module (222).

[0072] The receiver (216) transmits data such as voltage, current, temperature, and humidity of the battery module (222) received from the sensor module (224) to the abnormal detection evaluation module (218).

[0073] The abnormality detection evaluation module (218) analyzes data such as voltage, current, temperature, and humidity of the battery module (222) transmitted from the receiver (216) to detect and evaluate the abnormal state of the battery module (222). The abnormality detection evaluation module (218) compares the set discharge profile of the battery module (222) with the measured data to determine a match and evaluates whether the state of the battery module (222) currently being discharged is normal or abnormal. If the set discharge profile of the battery module (222) and the measured data do not match within an allowable error range, the state of the battery module (222) is evaluated as abnormal.

[0074] The automatic discharge and short module (220) serves to forcibly discharge or short-circuit the battery module (222). The automatic discharge and short module (220) functions to completely exhaust the remaining charge of the battery module (222), thereby reducing the risk of overheating or explosion of the battery module (222).

[0075] The integrated control module (226) controls the overall operation of the battery discharge device (200) according to an embodiment of the present invention. For example, the integrated control module (226) takes safety measures, such as ensuring that the discharge of the battery module (222) is performed normally or that the discharge is forcibly terminated, by controlling the automatic discharge and short circuit module (220) by referring to the state evaluation result of the battery module (222) transmitted from the abnormal detection evaluation module (218). In addition, the integrated control module (226) can modify the discharge profile of the discharge profile setting module (214) based on the state evaluation result of the battery module (222) received. The integrated control module (226) may be a control unit implemented as a processor.

[0076] FIG. 3 is a diagram illustrating a battery discharge method according to an embodiment of the present invention. The battery discharge method of FIG. 3 can be executed by the device configuration of FIG. 2 as part of the discharge / deactivation process (120) of FIG. 1.

[0077] As shown in FIG. 3, the collected battery modules (222) are simultaneously connected through a multi-channel battery connection module jig (212) to create an environment where multiple battery modules (222) can be discharged simultaneously (302).

[0078] In the discharge profile setting module (214), the type of each battery module (222) is identified, a preset discharge profile suitable for the type of battery module (222) is selected, discharge control parameters according to the voltage conditions of the battery module (222) are set, and discharge is started (304). The details regarding the discharge profile are as described above in FIG. 2.

[0079] While the battery module (222) is being discharged, each sensor module (224) collects voltage data of the battery module (222) in real time and transmits it to the abnormal detection evaluation module (218) through the receiver (216) (306).

[0080] The abnormality detection evaluation module (218) analyzes the voltage data of the battery module (222) transmitted through the receiver (216) to check whether an abnormal voltage pattern appears in the battery module (222) that is being discharged (308).

[0081] FIG. 6 is a diagram illustrating the types of abnormal voltage patterns of a battery module in a battery discharge process according to the present invention. As shown in FIG. 6, the abnormal voltage pattern may include a rapid voltage drop (602), an early voltage termination (604), an abnormally slow decrease (606), a voltage imbalance decrease (608), and an abnormal voltage peak (610). A rapid voltage drop (602) is a phenomenon in which the voltage drops rapidly. An early voltage termination (604) is a case in which the voltage drops to 0V first in a specific cell during discharge, causing a voltage drop to occur simultaneously with the discharge. An abnormally slow decrease (606) is a phenomenon in which the voltage drops abnormally slowly compared to the normal voltage for each battery type. A voltage imbalance decrease (608) is a case in which there is a large imbalance between channels during multi-channel voltage drop. An abnormal voltage peak (610) is a case in which the voltage temporarily rises rapidly during discharge, and may be, for example, a case in which reverse current flows into the circuit. The types of abnormal voltage patterns are not limited to those shown in FIG. 6 and may include other types of abnormal voltage patterns.

[0082] Returning to FIG. 3, the actual measured voltage Vmeasured(t) measured during the discharge of the battery module (222) according to an embodiment of the present invention can be expressed as Equation 1 below.

[0083] (Equation 1)

[0084] As shown in Equation 1, the voltage Vmeasured(t) measured according to actual time (t) may include the initial voltage Vocv at the time when diagnosis of the battery module (222) begins, the voltage drop due to the discharge current I(t) and the battery internal resistance Rint, and the voltage drop ΔVpolarization due to the polarization phenomenon caused by the deterioration of the battery module (222).

[0085] When Vmodel(t) is the normal discharge voltage (predicted value) for each type of battery module (222), the error ΔVerror(t) at time t between the actual measured voltage Vmeasrued(t) and the normal discharge voltage Vmodel(t) can be expressed as Equation 2 below.

[0086] (Equation 2)

[0087] If the error ΔVerror(t) at time t shown in Equation 2 exceeds a preset threshold value ('Yes' in 310), the abnormality detection evaluation module (218) determines that the battery module (222) is in an abnormal state in terms of voltage characteristics and outputs a warning signal to the integrated control module (226) to notify the abnormal state of the battery module (222) (312). At this time, the abnormality detection evaluation module (218) can determine which type of abnormal state the battery module (222) is among the abnormal state types shown in FIG. 6 from the actual measured voltage Vmeasrued(t) and normal discharge voltage Vmodel(t) for time t and the error ΔVerror(t). The warning signal output by the abnormality detection evaluation module (218) to the integrated control module (226) may include information about the type of abnormal state.

[0088] The integrated control module (226) ensures safety (314) by adjusting the discharge control conditions of the battery module (222) in response to the output of a warning signal from the abnormal detection evaluation module (218), thereby resolving the abnormal state of the battery module (222) or stopping the discharge. To this end, the integrated control module (226) may refer to information regarding the type of abnormal voltage pattern determined by the abnormal detection evaluation module (218). When the discharge control conditions are adjusted, the discharge of the battery module (222) continues according to the adjusted discharge control conditions. The adjustment of the discharge control conditions may include, for example, the adjustment of the discharge speed and the modification of the discharge profile.

[0089] On the other hand, if the error ΔVerror(t) at time t does not exceed a preset threshold value ('No' in 310), the battery discharge device (200) continues the normal discharge process of the battery module (222) (316).

[0090] When the discharge process is stopped (314) due to an abnormal voltage pattern of the battery module (222), or when the discharge is terminated through a normal discharge process (316), the automatic discharge and short module (220) induces a short circuit in each section of the battery module (222) to completely release the remaining energy of the battery module (222) (318). This safely terminates the discharge of the battery module (222).

[0091] In an embodiment of the present invention, voltage information of the battery module (222), such as voltage drop data, can be utilized as a key factor to identify an abnormal voltage pattern during the discharge process of the battery module (222). The monitoring of the occurrence of an abnormal state of the battery module (222) using such voltage drop data is described as follows.

[0092] Internal resistance is a major factor hindering current flow within a battery, and the higher the internal resistance, the greater the voltage drop during discharge. This is particularly pronounced at high discharge currents and has a significant impact on battery efficiency. The factors affecting a battery's internal resistance are as follows: Internal resistance increases in low-temperature environments, causing a significant voltage drop; additionally, as the battery undergoes repeated charging and discharging, the Solid Electrolyte Interphase (SEI) thickens, leading to increased resistance. Consequently, as the battery's internal resistance increases, power output decreases, and uneven current flow can cause overload in specific areas, potentially generating heat.

[0093] State of Charge (SOC) indicates the remaining charge state of a battery, and the lower the SOC, the greater the voltage drop. This is because the movement of lithium ions decreases as the SOC decreases. The factors affecting SOC are as follows. At low SOC, internal resistance increases, making it difficult for lithium ions to move, which leads to a larger voltage drop. Conversely, at high SOC, the voltage drop during initial discharge is small, but voltage fluctuations can increase with changes in temperature or load, which can place a load on the battery and cause performance degradation.

[0094] Batteries degrade as charging and discharging are repeated, leading to a gradual increase in voltage drop during discharge. The factors affecting battery cycle life and degradation are as follows: As charging and discharging are repeated, internal resistance increases and active materials are lost. This results in a decrease in battery performance. Furthermore, even when not in use, the internal structure of a battery can degrade over time due to chemical reactions; degraded batteries experience reduced capacity and increased voltage drop, leading to performance degradation.

[0095] The magnitude of the discharge current directly affects the voltage drop. As the discharge current increases, the voltage drop caused by internal resistance also increases. The major factors affecting battery discharge current are as follows. In the case of lithium-ion batteries, heat is generated and resistance increases because lithium ions must move rapidly at high discharge rates, leading to a larger voltage drop. Additionally, depending on the battery type, some batteries support high discharge rates, whereas others that do not may exhibit a greater voltage drop. High discharge currents raise the battery temperature, accelerating the rate of degradation and potentially leading to performance degradation.

[0096] The electrolyte is a critical component that facilitates the movement of lithium ions; if the electrolyte's concentration or condition is uneven or degraded, it can lead to a significant voltage drop. The factors affecting battery electrolyte concentration are as follows: Degradation can cause the electrolyte to decompose or reduce its concentration over time due to chemical reactions. Additionally, uneven distribution of the electrolyte concentration can increase resistance in specific regions, resulting in a voltage drop. Degraded electrolytes reduce battery efficiency and stability, potentially exacerbating voltage drop and thermal issues.

[0097] The present invention monitors the abnormal voltage pattern of the battery module (222) by analyzing voltage data while considering various factors, thereby enabling safe preemptive response to potential dangerous situations that may occur during the discharge process of the battery module (222).

[0098] Figure 4 is a diagram showing examples of voltage characteristics by battery type. As shown in Figure 4, NCM / NMC series batteries based on lithium-nickel-manganese-cobalt oxide have a reversible voltage range of 3.0-4.2V, and the oxidation reaction of manganese and cobalt accelerates above 4.2V. LFP series batteries based on lithium-iron-phosphate maintain a stable reversible voltage within a range of 2.5-3.65V, and battery damage may occur above 3.65V. These reversible voltage ranges are closely related to the risks that may occur during the battery recycling process. Batteries outside this voltage range can increase the risk of overcharging, over-discharging, chemical imbalance, internal short circuits, fire, and explosion. Therefore, the voltage status must be thoroughly checked during the recycling process, and batteries outside the reversible voltage range must be safely separated and disposed of.

[0099] The present invention monitors the abnormal state of the battery module (222) by analyzing voltage drop data considering such a reversible voltage range, thereby enabling a proactive response to potential dangerous situations that may occur during the discharge process of the battery module (222).

[0100] FIG. 5 is a diagram showing examples of normal voltage drop and abnormal voltage drop of a battery. As shown in FIG. 5, in an NCM-based battery, the normal voltage drop curve (e.g., the standard voltage drop curve of the battery) (502) and the overvoltage drop curve (504) are clearly distinguishable, and through this, the voltage drop characteristics of the battery module (222) during the discharge process can be analyzed to identify an abnormal state (overvoltage drop).

[0101] That is, the normal voltage drop (502) is characterized by a gradual voltage drop to 3V over 0.95 hours (about 55 minutes), followed by a rapid voltage drop after 0.95 hours (3V). In contrast, the overvoltage drop (504) shown in FIG. 5 is characterized by a relatively steeper voltage drop to 2.5V over 0.8 hours (about 48 minutes), followed by a rapid voltage drop after 0.8 hours (2.5V).

[0102] Since voltage drop characteristics may vary depending on the type of battery, a threshold value is set with a slight margin on the normal voltage drop characteristic curve of each battery (e.g., the standard voltage drop characteristic curve of the corresponding battery). If the actual voltage drop differs from the normal voltage drop and this difference exceeds the set threshold value, it is determined that an overvoltage drop characteristic has occurred. An abnormal state of the corresponding battery module (222) can be determined from this overvoltage drop characteristic. At this time, the overvoltage drop characteristic considers not only the magnitude of the voltage drop but also the time during which the voltage drop characteristic, as shown in FIG. 5, occurs. That is, when the actual voltage drop is relatively faster and larger compared to the normal voltage drop (standard voltage drop) and the difference exceeds a preset threshold value, this is recognized as an overvoltage drop of the battery, and based on this overvoltage drop, it can be determined that the corresponding battery module (222) is in an abnormal state.

[0103] The present invention monitors the abnormal state of the battery module (222) by analyzing voltage drop data in consideration of such normal voltage drop and overvoltage drop, thereby enabling a proactive response to potential dangerous situations that may occur during the discharge process of the battery module (222).

[0104] The above description is merely an illustrative explanation of the technical concept, and those skilled in the art will be able to make various modifications, changes, and substitutions within the scope of the essential characteristics without departing from the nature of the invention. Accordingly, the embodiments disclosed above and the attached drawings are intended to explain, not limit, the technical concept, and the scope of the technical concept is not limited by such embodiments and attached drawings. The scope of protection shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights.

Claims

1. A step of discharging at least one battery; A step of acquiring voltage drop data of at least one battery during the above discharge; and A battery discharge method comprising: a step of determining the state of at least one battery based on the above voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and larger than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

2. In Paragraph 1, A battery discharge method further comprising the step of adjusting the discharge control conditions of the at least one battery based on the overvoltage drop of the at least one battery.

3. In Paragraph 2, The adjustment of the above discharge control conditions is, A battery discharge method comprising adjusting the discharge rate of at least one battery based on an overvoltage drop of at least one battery.

4. In Paragraph 2, A step of identifying at least one type of battery; The method further includes the step of setting a discharge profile corresponding to the identified battery type, and A battery discharge method for performing a discharge of at least one battery by applying the discharge profile set above.

5. In Paragraph 4, The adjustment of the above discharge control conditions is, A battery discharge method comprising modifying the discharge profile based on an overvoltage drop of at least one battery.

6. In Paragraph 2, A battery discharge method further comprising the step of stopping the discharge of the at least one battery based on an overvoltage drop of the at least one battery.

7. In Paragraph 1, A battery discharge method in which at least one of the above batteries is a waste battery module for recycling.

8. In Paragraph 1, A battery discharge method in which the error at time t between the actual measured voltage and the normal discharge voltage of the above battery is expressed by the following formula. In the above equation, Vmodel(t) is the normal discharge voltage of the battery, Vmeasrued(t) is the actual measured voltage, and ΔVerror(t) is the error at time t between the normal discharge voltage Vmodel(t) and the actual measured voltage Vmeasrued(t).

9. In Paragraph 8, A battery discharge method in which the actual measured voltage Vmeasured(t) is expressed by the following formula. In the above equation, Vocv is the initial voltage at the time when the diagnosis of the battery begins, I(t) is the discharge current, Rint is the internal resistance of the battery, and ΔVpolarization is the voltage drop due to the polarization phenomenon caused by the degradation of the battery.

10. A battery connection portion provided to connect at least one battery for discharge; A sensor configured to detect the voltage of at least one battery; Includes an abnormality detection unit; and The above abnormality detection unit is, Acquiring voltage drop data of the at least one battery during the discharge of the at least one battery; A battery discharge device that determines the state of at least one battery based on the above voltage drop data, and determines that the battery is in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and larger than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

11. In Paragraph 10, It further includes a control unit configured to control the overall operation of the battery discharge device; The above control unit is, A battery discharge device that adjusts the discharge control conditions of the at least one battery based on the overvoltage drop of the at least one battery.

12. In Paragraph 11, The adjustment of the above discharge control conditions is, A battery discharge device comprising adjusting the discharge rate of at least one battery based on an overvoltage drop of at least one battery.

13. In Paragraph 11, The above control unit is, Identifying at least one type of battery; Setting a discharge profile corresponding to the above-identified battery type; A battery discharge device that performs the discharge of at least one battery by applying the discharge profile set above.

14. In Paragraph 13, The adjustment of the above discharge control conditions is, A battery discharge device comprising modifying the discharge profile based on an overvoltage drop of at least one battery.

15. In Paragraph 11, The above control unit is, A battery discharge device that stops the discharge of at least one battery based on an overvoltage drop of at least one battery.

16. In Paragraph 10, A battery discharge device in which at least one of the above batteries is a waste battery module for recycling.

17. In Paragraph 10, A battery discharge device that expresses the error at time t between the actual measured voltage and the normal discharge voltage of the above battery by the following formula. In the above equation, Vmodel(t) is the normal discharge voltage of the battery, Vmeasrued(t) is the actual measured voltage, and ΔVerror(t) is the error at time t between the normal discharge voltage Vmodel(t) and the actual measured voltage Vmeasrued(t).

18. In Paragraph 17, A battery discharge device in which the above actual measured voltage Vmeasured(t) is represented by the following formula. In the above equation, Vocv is the initial voltage at the time when the diagnosis of the battery begins, I(t) is the discharge current, Rint is the internal resistance of the battery, and ΔVpolarization is the voltage drop due to the polarization phenomenon caused by the degradation of the battery.

19. A step of discharging at least one battery; A step of acquiring voltage drop data of at least one battery during the above discharge; and A battery diagnosis method comprising the step of determining the state of at least one battery based on the above voltage drop data, wherein the battery is determined to be in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and larger than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

20. A battery connection portion provided to connect at least one battery for discharge; A sensor configured to detect the voltage of at least one battery; Includes an abnormality detection unit; and The above abnormality detection unit is, Acquiring voltage drop data of the at least one battery during the discharge of the at least one battery; A battery diagnostic device that determines the state of at least one battery based on the above voltage drop data, and determines that the battery is in an abnormal state due to overvoltage drop when the actual voltage drop of the battery is relatively faster and larger than the standard voltage drop of the battery, and when the difference between the standard voltage drop and the actual voltage drop exceeds a preset threshold value.

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