Energy storage device diagnostic system and method thereof

Abstract

An energy storage device diagnostic system according to one embodiment of the present invention includes an input signal providing device, an energy storage device, a temperature sensor, and a computing device. The input signal providing device provides a first input signal and a second input signal. The first input signal has a first frequency, and the second input signal has a second frequency different from the first frequency. The energy storage device stores energy through an electrochemical reaction. The energy storage device receives the first input signal and outputs a first output signal. The energy storage device receives the second input signal and outputs a second output signal. A temperature sensor is attached to the energy storage device. The temperature sensor measures a first temperature and a second temperature. The first temperature is the temperature of the energy storage device corresponding to the first input signal. The second temperature is the temperature of the energy storage device corresponding to the second input signal. The computing device calculates the entropy change of the energy storage device using the first output signal, the second output signal, the first temperature, and the second temperature.

Description

Technology Field

[0001] The present invention relates to a system for diagnosing an energy storage device. Specifically, the present invention relates to a system for calculating the entropy change of an energy storage device and diagnosing the energy storage device using the same. Background Technology

[0002] Energy storage devices (e.g., batteries) serve the function of storing and releasing electrical energy. Over time, the performance of energy storage devices can degrade, or dangerous phenomena such as thermal runaway may occur internally. Failure to detect abnormalities in energy storage devices in a timely manner not only leads to reduced efficiency but also poses a risk of safety accidents (fire, explosion). Therefore, it is crucial to continuously monitor the status of energy storage devices and detect any abnormalities at an early stage.

[0003] Changes in the entropy of an energy storage device can be utilized to detect abnormalities. Entropy is a physical quantity representing the disorder of a system, reflecting the internal chemical reactions and thermodynamic characteristics of the device. The entropy of an energy storage device changes during the charging and discharging processes, and analyzing these entropy changes allows for the identification of degradation states and abnormalities. Since the entropy change pattern of an energy storage device experiencing internal chemical abnormalities or thermal instability differs from that of a normal device, it is possible to diagnose the condition of the energy storage device by utilizing this characteristic. The problem to be solved

[0004] The object of the present invention is to provide a system and a method for calculating the change in entropy of an energy storage device using the temperature of the energy storage device, input signals input to the energy storage device having different frequencies, and output signals output from the energy storage device in response to the input signals. means of solving the problem

[0005] An energy storage device diagnostic system according to one embodiment of the present invention may include an input signal providing device, an energy storage device, a temperature sensor, and a computing device. The input signal providing device may provide a first input signal and a second input signal. The first input signal may have a first frequency, and the second input signal may have a second frequency different from the first frequency. The energy storage device may store energy through an electrochemical reaction. The energy storage device may receive the first input signal and output a first output signal. The energy storage device may receive the second input signal and output a second output signal. A temperature sensor may be attached to the energy storage device. The temperature sensor may measure a first temperature and a second temperature. The first temperature may be the temperature of the energy storage device corresponding to the first input signal. The second temperature may be the temperature of the energy storage device corresponding to the second input signal. The computing device may calculate the entropy change of the energy storage device using the first output signal, the second output signal, the first temperature, and the second temperature.

[0006] In one embodiment of the present invention, an artificial intelligence model may be stored in a computing device. The artificial intelligence model may determine at least one of the State of Health (SOH), State of Safety (SOS), State of Charge (SOC), and Remaining Useful Life (RUL) of an energy storage device based on entropy change.

[0007] In one embodiment of the present invention, the first frequency may be twice the second frequency.

[0008] In one embodiment of the present invention, the computing device can calculate the impedance of an energy storage device using Equation 1. The computing device can calculate the irreversible heat quantity using Equation 2. The computing device can calculate the heat transfer function using Equation 3. The computing device can calculate the reversible heat quantity using Equation 4. The computing device can calculate the entropy change using Equation 5.

[0009] Formula 1 is It can be. In Formula 1 is the impedance of the energy storage device, and is the voltage value of the second output signal, and is the second input signal, and It can be the second frequency.

[0010] Formula 2 is It can be. In Formula 2 It can be an irreversible amount of heat.

[0011] Formula 3 is It can be. In Equation 3 is the heat transfer function, and It may be a component corresponding to the first frequency among the frequency responses to the second temperature change.

[0012] Formula 4 is It can be. In Equation 4 is a reversible heat quantity, and is the component corresponding to the first frequency in the frequency response to the first temperature change, and It can be the first frequency.

[0013] Formula 5 is It can be. In Equation 5 is the entropy change, and is the Faraday constant, and is the first input signal, and can be the absolute value of the average temperature.

[0014] In one embodiment of the present invention, a first input terminal and a second input terminal may be further included to receive a first input signal and a second input signal, respectively. The potential of the first input terminal may be higher than the potential of the second input terminal. A first surface on which the first input terminal and the second input terminal are located, a second surface not facing the first surface, and a third surface facing the second surface are defined in the energy storage device. A temperature sensor may be positioned to overlap the center of the second surface, positioned to overlap the center of the third surface, or positioned between the center of the third surface and the first input terminal.

[0015] An energy storage device diagnostic method according to one embodiment of the present invention may include an input signal providing step, a temperature change measurement step, and an entropy change calculation step.

[0016] In the input signal providing step, the input signal providing device may sequentially provide a first input signal and a second input signal to the energy storage device. The first input signal has a first frequency, and the second input signal may have a second frequency different from the first frequency.

[0017] In the temperature change measurement step, a temperature sensor attached to the energy storage device may measure a first temperature and a second temperature. The first temperature may be the temperature of the energy storage device corresponding to the first input signal. The second temperature may be the temperature of the energy storage device corresponding to the second input signal.

[0018] In the entropy change calculation step, the computing device can calculate the entropy change of the energy storage device using a first output signal, a second output signal, a first temperature, and a second temperature.

[0019] An energy storage device diagnostic method according to one embodiment of the present invention may further include an energy storage device diagnostic step. In the energy storage device diagnostic step, an artificial intelligence model stored in a computing device may determine at least one of the State of Health (SOH), State of Safety (SOS), State of Charge (SOC), and Remaining Useful Life (RUL) of the energy storage device based on the change in entropy.

[0020] In one embodiment of the present invention, the first frequency may be twice the second frequency.

[0021] In one embodiment of the present invention, the entropy change calculation step may include an impedance calculation step, an irreversible heat quantity calculation step, a heat transfer function calculation step, a reversible heat quantity calculation step, and a final calculation step.

[0022] In the impedance calculation step, the computing device can calculate the impedance of the energy storage device using Equation 1. Equation 1 is It can be. In Formula 1 is the impedance of the energy storage device, and is the voltage value of the second output signal, and is the second input signal, and It can be the second frequency.

[0023] In the step of calculating the irreversible heat quantity, the computing device can calculate the irreversible heat quantity using Equation 2. Equation 2 is It can be. In Formula 2 It can be an irreversible amount of heat.

[0024] In the heat transfer function calculation step, the computing device can calculate the heat transfer function using Equation 3. Equation 3 is It can be. In Equation 3 is the heat transfer function, and It may be a component corresponding to the first frequency among the frequency responses to the second temperature change.

[0025] In the reversible heat quantity calculation step, the computing device can calculate the reversible heat quantity using Equation 4. Equation 4 is It can be. In Equation 4 is a reversible heat quantity, and is the component corresponding to the first frequency in the frequency response to the first temperature change, and It can be the first frequency.

[0026] In the final output stage, the computing device can calculate the change in entropy using Equation 5. Equation 5 is It can be. In Equation 5 is the entropy change, and is the Faraday constant, and is the first input signal, and can be the absolute value of the average temperature.

[0027] In one embodiment of the present invention, a first input terminal and a second input terminal may be further included to receive a first input signal and a second input signal, respectively. The potential of the first input terminal may be higher than the potential of the second input terminal. A first surface on which the first input terminal and the second input terminal are located, a second surface not facing the first surface, and a third surface facing the second surface are defined in the energy storage device. A temperature sensor may be positioned to overlap the center of the second surface, positioned to overlap the center of the third surface, or positioned between the center of the third surface and the first input terminal. Effects of the invention

[0028] According to one embodiment of the present invention, the present invention may provide a system and a method for calculating the entropy change of an energy storage device using the temperature of the energy storage device, input signals input to the energy storage device having different frequencies, and output signals output from the energy storage device in response to the input signals. Brief explanation of the drawing

[0029] FIG. 1 is an exemplary block diagram of an energy storage device diagnostic system according to one embodiment of the present invention. FIG. 2 illustrates, in an exemplary manner, an energy storage device diagnostic system according to one embodiment of the present invention. FIG. 3a illustrates an exemplary graph of the first input signal and the second input signal. FIG. 3b illustrates an exemplary graph of the first temperature and the second temperature. FIG. 3c exemplarily illustrates the magnitude of the frequency response of the first temperature change and the second temperature change. Figures 4a to 4d are graphs showing the relationship between entropy change and SOC depending on whether the energy storage device is degraded. FIG. 5 illustrates, in an exemplary manner, an energy storage device diagnostic system according to another embodiment of the present invention. FIG. 6 illustrates, in an exemplary manner, an energy storage device diagnostic system according to another embodiment of the present invention. Figure 7 is a graph showing the relationship between entropy change and SOC for each of the energy storage device diagnostic systems shown in Figures 2, 5, and 5. FIG. 8 is an exemplary flowchart illustrating a method for diagnosing an energy storage device according to one embodiment of the present invention. Figure 9 illustrates an exemplary flowchart of the entropy change calculation step of Figure 8. Specific details for implementing the invention

[0030] Preferred embodiments of the present invention will be described in more detail below with reference to the attached drawings. In the drawings, the proportions and dimensions of the components may be exaggerated for the effective explanation of the technical content.

[0031] Terms such as "include" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] In addition, when a component is described as "above," it refers to the area above or below the component, and does not necessarily mean that it is located on the upper side relative to the direction of gravity.

[0033] In addition, where it is stated that a component is "connected" or "combined" to another component, this may include not only cases where the component is directly connected or combined to the other component, but also cases where the component is indirectly connected or combined through another component.

[0034] In addition, terms such as "first," "second," etc., may be used to describe a component; however, these terms are intended merely to distinguish the component from other components and are not intended to limit the essence, order, or sequence of the component.

[0035] Preferred embodiments of the present invention will be described in more detail below with reference to the attached drawings. In the drawings, the proportions and dimensions of the components may be exaggerated for the effective explanation of the technical content.

[0036] FIG. 1 is an exemplary block diagram of an energy storage device diagnostic system (DGS) according to one embodiment of the present invention.

[0037] FIG. 2 illustrates an exemplary view of an energy storage device diagnostic system (DGS) according to one embodiment of the present invention.

[0038] Referring to FIGS. 1 and 2, an energy storage device diagnostic system (DGS) according to one embodiment of the present invention may include an input signal providing device (PWR), an energy storage device (STR), a temperature sensor (TSS), a computational device (PRC), a first input terminal (INP1), and a second input terminal (INP2). For example, the energy storage device (STR) may be a battery.

[0039] FIG. 3a is a first input signal ( ) and second input signal ( This is an exemplary graph of ).

[0040] Fig. 3b shows the first temperature ( ) and second temperature( This is an exemplary graph of ).

[0041] FIG. 3c shows the magnitude of the frequency response of the first temperature change and the second temperature change ( , This is an exemplary illustration of ).

[0042] Referring to FIGS. 2 and FIGS. 3a, the input signal providing device (PWR) provides a first input signal ( ) and second input signal ( ) can provide. The first input signal ( ) has a first frequency, and a second input signal ( ) may have a second frequency different from the first frequency. In one embodiment of the present invention, the first frequency may be twice the second frequency.

[0043] Referring to Figures 2 and 3a, an energy storage device (STR) can store energy through an electrochemical reaction.

[0044] The energy storage device (STR) has a first input signal ( It can receive ) as input and output a first output signal. The energy storage device (STR) receives a second input signal ( It can receive ) as input and output a second output signal.

[0045] Referring to FIGS. 2 and FIGS. 3a, a temperature sensor (TSS) can be attached to an energy storage device (STR).

[0046] The temperature sensor (TSS) is the first temperature ( ) and second temperature( ) can be measured. The first temperature ( ) is the first input signal ( It may be the temperature of the energy storage device (STR) corresponding to ). The second temperature ( ) is the second input signal ( It may be the temperature of an energy storage device (STR) corresponding to ).

[0047] Referring to FIGS. 2 and FIGS. 3a, the computational unit (PRC) has a first output signal, a second output signal, and a first temperature ( ), and second temperature ( Using ) the entropy change of an energy storage device ( ) can be calculated. Hereinafter, using Equations 1 to 5, the computing device (PRC) calculates the entropy change of the energy storage device ( Explains the process of calculating ).

[0048] The computational unit (PRC) can calculate the impedance of the energy storage device (STR) using Equation 1.

[0049] Formula 1 is It could be.

[0050] In Formula 1 is the impedance of the energy storage device (STR), and is the voltage value of the second output signal, and is the second input signal, and It can be the second frequency.

[0051] The computational unit (PRC) can calculate the irreversible heat quantity using Equation 2.

[0052] Formula 2 is It could be.

[0053] In Formula 2 It can be an irreversible amount of heat.

[0054] The computational unit (PRC) can calculate the heat transfer function using Equation 3.

[0055] Formula 3 is It could be.

[0056] In Formula 3 is the heat transfer function, and It may be a component corresponding to the first frequency among the frequency responses to the second temperature change.

[0057] The computational unit (PRC) can calculate the reversible heat quantity using Equation 4.

[0058] Formula 4 is It could be.

[0059] In Formula 4 is a reversible heat quantity, and is the component corresponding to the first frequency in the frequency response to the first temperature change, and It can be the first frequency.

[0060] The computational unit (PRC) can calculate the change in entropy using Equation 5.

[0061] Formula 5 is It could be.

[0062] In Equation 5 is the entropy change, and is the Faraday constant, and is the first input signal, and can be the absolute value of the average temperature.

[0063] FIGS. 4a to 4d show the entropy change ( This is a graph showing the relationship between ) and SOC (State of Charge) depending on whether the energy storage device (STR) is degraded.

[0064] Referring to FIGS. 4a to 4d, the relationship between the entropy change of the energy storage device (STR) and the SOC (Aged Cell) when the energy storage device (STR) is degraded may differ from the relationship between the entropy change of the energy storage device (STR) and the SOC (Fresh Cell) when the energy storage device (STR) is not degraded.

[0065] In other words, if the aforementioned differences are measured under various conditions (over-temperature, over-current, under-voltage, cycling at over-temperature) and an artificial intelligence model is trained using this, the entropy change ( State of Charge (SOC) can be estimated from ).

[0066] In one embodiment of the present invention, an artificial intelligence model may be stored in a computing device (PRC). The artificial intelligence model is an entropy change ( Based on ), at least one of the State of Health (SOH), State of Safety (SOS), State of Charge (SOC), and Remaining Useful Life (RUL) of the energy storage device (STR) can be determined.

[0067] Below, the prior art and the present invention are compared, and the effects of the present invention are explained.

[0068] Among conventional technologies, the Potentiometric Method is a method for analyzing the thermodynamic characteristics of a system (in this invention, the change in entropy) by measuring the potential difference (voltage) between electrodes in a solution. Using the Potentiometric Method, the change in entropy ( When measuring ), there is a problem in that it takes a long time to measure and requires a separate device (e.g., a thermal chamber) that occupies a large volume. Therefore, it is difficult to miniaturize the energy storage device diagnostic system (DGS) using the potentiometric method.

[0069] Among conventional technologies, the Calorimetric Method is a method for analyzing changes in entropy by measuring the amount of heat released or absorbed during a reaction process. Using the Calorimetric Method, changes in entropy ( When measuring ), the change in entropy ( using the Potentiometric Method It has the advantage of taking less time than when measuring ). However, using the Calorimetric Method to measure the change in entropy ( Even when measuring ), a separate device that occupies a large volume is required. Therefore, it is difficult to miniaturize the energy storage device diagnostic system (DGS) even when using the Calorimetric Method.

[0070] In conclusion, analyzing entropy changes using conventional technologies presents problems such as difficulty in miniaturization and the requirement of a long analysis time. On the other hand, the energy storage device diagnostic method (DGM) of the present invention does not require a separate device (e.g., a thermal chamber), and therefore is inexpensive, allows for miniaturization, has a short measurement time, and possesses high accuracy.

[0071] Hereinafter, using FIGS. 5 to 7, the change in entropy using the Potentiometric Method (potential difference measurement method) Measurement results of ) and entropy change using the energy storage device diagnostic system (DGS, DGS-1, DGS-2) of the present invention ( Explain by comparing the measurement results of ).

[0072] FIG. 5 illustrates an exemplary view of an energy storage device diagnostic system (DGS-1) according to another embodiment of the present invention.

[0073] FIG. 6 illustrates an exemplary view of an energy storage device diagnostic system (DGS-2) according to another embodiment of the present invention.

[0074] Figure 7 is a graph showing the relationship between entropy change and SOC (State of Charge) for each of the energy storage device diagnostic systems (DGS, DGS-1, DGS-2) illustrated in Figures 2, 5, and 6.

[0075] The first input terminal (INP1) and the second input terminal (INP2) are the first input signal ( ) and second input signal ( Each of the following can be input. A first surface (PLN1), a second surface (PLN2), and a third surface (PLN3) are defined in which a first input terminal (INP1) and a second input terminal (INP2) are located in the energy storage device (STR).

[0076] A first input terminal (INP1) and a second input terminal (INP2) may be located on the first surface (PLN1). The potential of the first input terminal (INP1) may be higher than the potential of the second input terminal (INP2). In one embodiment of the present invention, the first input terminal (INP1) and the second input terminal (INP2) may be omitted.

[0077] The second face (PLN2) may not face the first face (PLN1).

[0078] The third side (PLN3) can face the second side (PLN2).

[0079] Referring to FIG. 2, a temperature sensor (TSS) of an energy storage device diagnostic system (DGS) according to one embodiment of the present invention may be positioned to overlap with the center of a second plane (PLN2).

[0080] Referring to FIG. 5, the temperature sensor (TSS) of the energy storage device diagnostic system (DGS-1) according to one embodiment of the present invention may be positioned to overlap with the center of the third surface (PLN3).

[0081] Referring to FIG. 6, the temperature sensor (TSS) of the energy storage device diagnostic system (DGS-2) according to one embodiment of the present invention may be located between the center of the third surface (PLN3) and the first input terminal (INP1).

[0082] Referring to FIG. 7, the entropy change using the energy storage device diagnostic system (DGS, DGS-1, DGS-2) of the present invention ( The measurement result of ) is the entropy change using the conventional technology Potentiometric Method (potential difference measurement method) It can be seen that the measurement results are similar to those of ). That is, when using the energy storage device diagnostic system (DGS, DGS-1, DGS-2) of the present invention, the change in entropy (in a shorter time with similar accuracy to the case where the Potentiometric Method is used) ) can be measured.

[0083] Referring to FIGS. 2, FIGS. 5, FIGS. 6, and FIGS. 7, if the temperature sensor (TSS) is located between the center of the second surface (PLN2) or the center of the third surface (PLN3) or the center of the third surface (PLN3) and the first input terminal (INP1), the entropy change ( The accuracy of the measurement can be high.

[0084] FIG. 8 is an exemplary flowchart of an energy storage device diagnosis method (DGM) according to one embodiment of the present invention.

[0085] FIG. 9 illustrates an exemplary flowchart of the entropy change calculation step (S300) of FIG. 8.

[0086] Referring to FIG. 8, an energy storage device diagnosis method (DGM) according to one embodiment of the present invention may include an input signal providing step (S100), a temperature change measurement step (S200), an entropy change calculation step (S300), and an energy storage device diagnosis step (S400).

[0087] In the input signal providing step (S100), the input signal providing device (PWR) sends a first input signal ( ) and second input signal ( ) can be provided sequentially. The first input signal ( ) has a first frequency, and a second input signal ( ) may have a second frequency different from the first frequency. In one embodiment of the present invention, the first frequency may be twice the second frequency.

[0088] In the temperature change measurement step (S200), the temperature sensor (TSS) attached to the energy storage device (STR) is at the first temperature ( ) and second temperature( ) can be measured. The first temperature ( ) is the first input signal ( It may be the temperature of the energy storage device (STR) corresponding to ). The second temperature ( ) is the second input signal ( It may be the temperature of an energy storage device (STR) corresponding to ).

[0089] In the entropy change calculation step (S300), the computing device (PRC) has a first output signal, a second output signal, and a first temperature ( ), and second temperature ( Using ) the entropy change of an energy storage device ( ) can be produced.

[0090] In the energy storage device diagnosis step (S400), the artificial intelligence model stored in the computing device (PRC) can determine at least one of the State of Health (SOH), State of Safety (SOS), State of Charge (SOC), and Remaining Useful Life (RUL) of the energy storage device (STR) based on the change in entropy. In one embodiment of the present invention, the energy storage device diagnosis step (S400) may be omitted.

[0091] Referring to FIG. 9, the entropy change calculation step (S300) may include an impedance calculation step (S310), an irreversible heat quantity calculation step (S320), a heat transfer function calculation step (S330), a reversible heat quantity calculation step (S340), and a final calculation step (S350).

[0092] In the impedance calculation step (S310), the computational unit (PRC) can calculate the impedance of the energy storage device (STR) using Equation 1. Equation 1 is It can be. In Formula 1 is the impedance of the energy storage device (STR), and is the voltage value of the second output signal, and is the second input signal, and It can be the second frequency.

[0093] In the irreversible heat quantity calculation step (S320), the computing device (PRC) can calculate the irreversible heat quantity using Equation 2. Equation 2 is It can be. In Formula 2 It can be an irreversible amount of heat.

[0094] In the heat transfer function calculation step (S330), the computational unit (PRC) can calculate the heat transfer function using Equation 3. Equation 3 is It can be. In Equation 3 is the heat transfer function, and It may be a component corresponding to the first frequency among the frequency responses to the second temperature change.

[0095] In the reversible heat quantity calculation step (S340), the computing device (PRC) can calculate the reversible heat quantity using Equation 4. Equation 4 is It can be. In Equation 4 is a reversible heat quantity, and is the component corresponding to the first frequency in the frequency response to the first temperature change, and It can be the first frequency.

[0096] In the final calculation step (S350), the computing unit (PRC) can calculate the entropy change using Equation 5. Equation 5 is It can be. In Equation 5 is the entropy change, and is the Faraday constant, and is the first input signal, and can be the absolute value of the average temperature.

[0097] Although the invention has been described with reference to exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims. Furthermore, the exemplary embodiments disclosed in the invention are not intended to limit the technical spirit of the invention, and all technical spirits within the scope of the following claims and their equivalents should be interpreted as being included within the scope of the rights of the invention. Explanation of the symbols

[0098] DGS: Energy Storage System Diagnostic System PWR: Input Signal Provider STR: Energy storage device TSS: Temperature sensor PRC: Arithmetic Unit INP1: First Input Complex INP2: Second input terminal PLN1: First surface PLN2: 2nd side PLN3: 3rd side DGM: Energy Storage Device Diagnostic Method S100: Input signal provision step S200: Temperature change measurement step S300: Entropy change calculation step S400: Energy storage device diagnostic step S310: Impedance calculation step S320: Irreversible heat calculation step S330: Heat transfer function calculation step S340: Reversible heat calculation step S350: Final output stage

Claims

Claim 1 An energy storage device diagnostic system comprising: an input signal providing device that provides a first input signal and a second input signal, wherein the first input signal has a first frequency and the second input signal has a second frequency different from the first frequency; an energy storage device that stores energy through an electrochemical reaction, receives the first input signal and outputs a first output signal, and receives the second input signal and outputs a second output signal; a temperature sensor attached to the energy storage device and measuring a first temperature and a second temperature, wherein the first temperature is the temperature of the energy storage device corresponding to the first input signal and the second temperature is the temperature of the energy storage device corresponding to the second input signal; and a computing device that calculates the entropy change of the energy storage device using the first output signal, the second output signal, the first temperature, and the second temperature. Claim 2 An energy storage device diagnostic system according to claim 1, wherein an artificial intelligence model is stored in the computing device, and the artificial intelligence model determines at least one of the State of Health (SOH), State of Safety (SOS), State of Charge (SOC), and Remaining Useful Life (RUL) of the energy storage device based on the change in entropy. Claim 3 An energy storage device diagnostic system according to claim 1, wherein the first frequency is twice the second frequency. Claim 4 In claim 3, the computing device calculates the impedance of the energy storage device using Equation 1, calculates the irreversible heat quantity using Equation 2, calculates the heat transfer function using Equation 3, calculates the reversible heat quantity using Equation 4, calculates the entropy change using Equation 5, and Equation 1 is and, in the above Formula 1 is the impedance of the energy storage device, and is the voltage value of the second output signal above, and is the second input signal above, and is the above second frequency, and the above Equation 2 is and, in the above formula 2 is the above irreversible heat quantity, and the above Equation 3 is and, in the above formula 3 is the above heat transfer function, and is the component corresponding to the first frequency among the frequency response to the change in the second temperature, and Equation 4 is and, in the above formula 4 is the above-mentioned reversible heat quantity, and is a component corresponding to the first frequency among the frequency response to the change in the first temperature, and is the first frequency above, and Equation 5 above is and, in the above formula 5 is the above entropy change, and is the Faraday constant, and is the first input signal, and An energy storage device diagnostic system that is the absolute value of the average temperature. Claim 5 An energy storage device diagnostic system according to claim 3, further comprising a first input terminal and a second input terminal receiving each of the first input signal and the second input signal, wherein the potential of the first input terminal is higher than the potential of the second input terminal, and wherein a first surface on which the first input terminal and the second input terminal are located, a second surface not facing the first surface, and a third surface facing the second surface are defined, and wherein the temperature sensor is positioned to overlap the center of the second surface, to overlap the center of the third surface, or positioned between the center of the third surface and the first input terminal. Claim 6 An energy storage device diagnostic method comprising: an input signal providing device sequentially providing a first input signal and a second input signal to an energy storage device, wherein the first input signal has a first frequency and the second input signal has a second frequency different from the first frequency; a temperature change measuring step wherein a temperature sensor attached to the energy storage device measures a first temperature and a second temperature, wherein the first temperature is the temperature of the energy storage device corresponding to the first input signal and the second temperature is the temperature of the energy storage device corresponding to the second input signal; and an entropy change calculation step wherein a computing device calculates the entropy change of the energy storage device using a first output signal corresponding to the first input signal, a second output signal corresponding to the second input signal, the first temperature, and the second temperature. Claim 7 An energy storage device diagnostic method according to claim 6, further comprising an energy storage device diagnostic step, wherein, in the energy storage device diagnostic step, an artificial intelligence model stored in the computing device determines at least one of the SOH (State of Health), SOS (State of Safety), SOC (State of Charge), and RUL (Remaining Useful Life) of the energy storage device based on the entropy change. Claim 8 In claim 6, the energy storage device diagnostic method wherein the first frequency is twice the second frequency. Claim 9 In claim 6, the step of calculating the entropy change comprises the computing device calculating the impedance of the energy storage device using Equation 1, and Equation 1 is and, in the above Formula 1 is the impedance of the energy storage device, and is the voltage value of the second output signal above, and is the second input signal mentioned above, and is an impedance calculation step at the second frequency above; the computing device calculates an irreversible heat quantity using Equation 2, and Equation 2 is and, in the above Formula 2 is an irreversible heat quantity calculation step, which is the irreversible heat quantity above; the computing device calculates a heat transfer function using Equation 3, and Equation 3 is and, in the above Equation 3 is the above heat transfer function, and is a step of calculating a heat transfer function which is a component corresponding to the first frequency among the frequency response to the change in the second temperature; the computing device calculates a reversible heat quantity using Equation 4, and Equation 4 is and, in the above Equation 4 is the above-mentioned reversible heat quantity, and is a component corresponding to the first frequency among the frequency response to the change in the first temperature, and is a reversible heat quantity calculation step at the first frequency; and the computing device calculates the entropy change using Equation 5, and Equation 5 is and, in the above Equation 5 is the above entropy change, and is the Faraday constant, and is the first input signal, and An energy storage device diagnostic method that further includes a final calculation step of the absolute value of the average temperature. Claim 10 A method for diagnosing an energy storage device according to claim 8, further comprising a first input terminal and a second input terminal receiving each of the first input signal and the second input signal, wherein the potential of the first input terminal is higher than the potential of the second input terminal, and a first surface on which the first input terminal and the second input terminal are located, a second surface not facing the first surface, and a third surface facing the second surface are defined in the energy storage device, wherein the temperature sensor is positioned to overlap the center of the second surface, positioned to overlap the center of the third surface, or positioned between the center of the third surface and the first input terminal.

Images