WO2020101271A1 - Procédé de prédiction de changement de température associé à des états de batterie normale et de court-circuit - Google Patents

Procédé de prédiction de changement de température associé à des états de batterie normale et de court-circuit Download PDF

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Publication number
WO2020101271A1
WO2020101271A1 PCT/KR2019/015100 KR2019015100W WO2020101271A1 WO 2020101271 A1 WO2020101271 A1 WO 2020101271A1 KR 2019015100 W KR2019015100 W KR 2019015100W WO 2020101271 A1 WO2020101271 A1 WO 2020101271A1
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Prior art keywords
battery
temperature
soc
entropy
change
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English (en)
Korean (ko)
Inventor
도칠훈
김석환
박준우
손홍관
엄승욱
유지현
이유진
최선화
하윤철
김민주
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Korea Electrotechnology Research Institute KERI
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Korea Electrotechnology Research Institute KERI
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Priority claimed from KR1020180138419A external-priority patent/KR102558017B1/ko
Priority claimed from KR1020190129659A external-priority patent/KR102895113B1/ko
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Publication of WO2020101271A1 publication Critical patent/WO2020101271A1/fr
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
    • G01R31/3835—Arrangements for monitoring battery or accumulator variables, e.g. SoC involving only voltage measurements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a method for predicting a temperature change with respect to the normal and short-circuit state of a battery, and more specifically, calculating the temperature change with respect to the normal and short-circuit state of the battery using specific characteristics and predefined relations of the battery How to do.
  • a predetermined current flows inside the battery.
  • the normal operating condition of the battery is a state in which artificial control of the current is possible, and can be divided into three operating modes: constant current, constant voltage and constant output.
  • a constant current technique is mainly used in the research process of a battery.
  • the use of the battery is usually made in an open space. Therefore, in a very cold or hot environment, the surrounding environment of the battery may deviate from the recommended operating temperature of the battery, and accordingly, a problem in operation of the battery may occur.
  • the multi-stacked collective battery is difficult to dissipate heat, and thus performs a charge / discharge operation in an environment close to an adiabatic state, and accordingly, a problem may occur in the operation of the battery.
  • This pseudo-adiabatic condition may more easily occur when performing rapid charging or discharging in an aggregate cell. In this case, the voltage / current / temperature of the battery rapidly changes.
  • the data sheet provided by the battery manufacturer recommends the charging temperature of the battery used for small electronic devices, energy storage devices (ESS), and electric vehicles in the range of 0 °C to 50 °C based on the battery surface temperature, and the discharge temperature. Is recommended in the range of -20 ° C to 75 ° C based on the surface temperature of the battery.
  • ESS energy storage devices
  • the temperature difference between the surface and the inside of the battery gradually increases, and even if the surface temperature of the battery is within a safe (regulated) range, the internal temperature rises rapidly and there is a possibility of local ignition.
  • the first thing to be established in order to identify the heat generation characteristics of the battery is to establish the battery entropy index by accurately measuring the entropy of the battery.
  • an entropy measurement method using an isothermal galvanostatic intermittent transient technique (I-GITT) and an open circuit voltage (OCV) measurement by discrete stepping of temperature under various SOC conditions There is an entropy measurement method used.
  • I-GITT isothermal galvanostatic intermittent transient technique
  • OCV open circuit voltage
  • the present invention aims to solve the above and other problems. Another object is to provide a method for arranging the thermal chemistry of heat and endotherm of the battery and calculating the entropy of the battery.
  • Another object is to provide a method for calculating a change in temperature of a battery according to an initial temperature and SOC of the battery by applying the measured entropy of the battery to a mathematical formula summarized with respect to the thermochemical characteristics of the battery.
  • Another object is to provide a method for deriving the open circuit voltage, internal resistance, entropy, and specific heat, which are inherent characteristics of a battery, according to a state of charge (SOC).
  • SOC state of charge
  • Another object is to provide a relationship modeling the thermochemical properties of a battery short circuit according to a differential charge state (dSOC).
  • Another object is to provide a method for calculating a voltage / current / temperature change for a short circuit of a battery according to a state of charge (SOC) or time using an open circuit voltage, internal resistance, entropy, and specific heat, which are inherent characteristics of the battery. have.
  • SOC state of charge
  • Another object is to provide a battery analysis method that can be applied to determine a safe use possibility by predicting a future short-circuit condition in advance before a short-circuit of a corresponding battery by analyzing a change in voltage / current / temperature with respect to a short-circuit of the battery. .
  • Another object is to provide a battery operation method to safely use the battery by predicting in advance characteristics of various small and large capacity single and aggregated battery operating loads such as an electric vehicle, an electric ship, an electric aircraft, and an energy storage device. have.
  • SOC state of charge
  • the end temperature of the battery after the constant current charging or the constant current discharge of the battery with respect to the initial temperature of the battery before the constant current charging or the constant current discharge of the battery is calculated by a predefined relation using the measured entropy It provides a method for calculating the temperature change of the battery, characterized in that.
  • SOC state of charge
  • an entropy characteristic for each SOC of a battery may be more accurately measured using a method of measuring entropy through cooling of the battery.
  • C ratio of the charging current value to the battery capacity
  • the difficulty of setting the termination boundary condition with respect to time can be avoided by analyzing the voltage / current / temperature change relationship for the short circuit of the battery according to the differential charge state (dSOC).
  • the simplified analysis method can greatly contribute to improving the safety of a large-scale battery system by easily providing information on the external short circuit of the battery, and the active set battery in use during the mission can cause a failure.
  • dSOC differential charge state
  • the present invention by predicting a voltage / current / temperature change for a short circuit of a battery, it is designed to prevent thermal shock conditions that may occur during battery operation in advance to improve the cycle life of the battery This can increase the cumulative energy storage of the battery, thereby reducing the cost of purchasing the battery compared to the period of use.
  • FIG. 1 is a flowchart illustrating a method for measuring entropy through cooling of a battery according to an embodiment of the present invention
  • FIG. 2 is a graph showing an open circuit voltage of a battery in charging and discharging for each battery SOC for a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention
  • FIG. 3 is a view showing the change in battery voltage by temperature by moving the result of FIG. 2 at 0.5V intervals;
  • 4 and 5 are diagrams showing open circuit voltage information according to battery SOC for each temperature of the battery when charging and discharging the battery;
  • 6 and 7 are diagrams showing a polynomial relationship of open circuit voltage information according to battery SOC for each temperature of the battery during battery charging and discharging;
  • FIG. 8 shows the internal resistance of the battery against the battery SOC at absolute temperatures of 298K, 313K, and 328K when charging or discharging the battery in the entropy measurement method through cooling of the battery according to an embodiment of the present invention and the battery temperature change calculation method using the method. Illustrated drawings;
  • 9 and 10 is a battery for a battery SOC at a temperature condition of 298K, 313K, 328K during battery charging and discharging in a method for measuring entropy through cooling of a battery according to an embodiment of the present invention and a method for calculating a change in battery temperature using the method
  • FIG. 11 is a view showing a change in the average internal resistance of a battery according to temperature in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention
  • FIG. 12 is a view showing a battery internal resistance value for SOC by temperature during charging and discharging of a battery in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention
  • 13 to 15 are graphs for measuring the specific heat of a battery in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention
  • 16 to 18 is a battery over time when gradually cooling a battery heated to 60 ° C. while being charged or discharged with a predetermined battery SOC in an entropy measurement method through cooling of the battery according to an embodiment of the present invention.
  • 19 and 20 are graphs showing a change in the battery open circuit voltage with respect to the temperature change from the relationship between the battery temperature change and the open circuit voltage with time shown in FIGS. 16 to 18;
  • 21 is a diagram illustrating a battery open circuit voltage for a battery temperature measured by a battery adiabatic low-speed cooling method for each battery SOC section set in a method for measuring entropy through cooling of a battery according to an embodiment of the present invention
  • 22 is a diagram showing an example of calculating an entropy and an enthalpy along with a primary function relationship of an open circuit voltage to temperature for each battery SOC section by an entropy measurement method through cooling of a battery according to an embodiment of the present invention
  • 23 and 24 are battery entropy values having a temperature change between 60 ° C and 30 ° C according to a prior art battery entropy measurement method and batteries having a temperature change between 60 ° C and 20 ° C according to a battery entropy measurement method of the present invention
  • 25 is a view showing a battery entropy value according to a battery SOC by the battery entropy measurement method of the present invention divided into four sections;
  • 26 is a view showing the entropy polynomial according to the SOC area of the battery according to the battery entropy measurement method of the present invention.
  • 27 is a graph showing the temperature change for each location of a battery and a battery chamber during adiabatic discharge of a battery in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention
  • 31 is a flow chart illustrating a method for deriving a unique characteristic of a battery according to an embodiment of the present invention
  • Fig. 32A schematically shows an equivalent circuit of the battery when the battery is shorted
  • 32B is a diagram schematically showing a process in which the battery generates heat when the battery is short-circuited
  • 33A is a block diagram of an apparatus for predicting a short circuit of a battery according to an embodiment of the present invention.
  • 33B is a flowchart illustrating a method of predicting a short circuit characteristic of a battery according to an embodiment of the present invention
  • 34A to 34C are graphs showing actually measured voltage / current / temperature changes of the corresponding battery according to a change in the size of the load resistance when the battery is short-circuited;
  • 35A and 35B are graphs showing a change in voltage / current / temperature of a battery according to time or SOC calculated based on a predefined equation for a short circuit of a battery according to an embodiment of the present invention ;
  • 36A and 36B are graphs showing a voltage / current / temperature change of a battery calculated according to a predefined equation for a short-circuit cell circuit according to another embodiment of the present invention according to time or SOC;
  • 37A and 37B are graphs illustrating voltage / current / temperature changes of a battery calculated according to a predefined equation for a short-circuit battery circuit according to another embodiment of the present invention according to time or SOC ;
  • 39 is a graph showing a result of calculating a voltage change for a short circuit of a battery according to various conditions
  • 40 is a graph showing a result of calculating a temperature change for a short circuit of a battery according to various conditions
  • 41 is a graph showing a result of calculating a final temperature of a battery according to a change in external short circuit resistance.
  • the present invention proposes a method for arranging the thermal chemical relationship between heat generation and endotherm of the battery and calculating the entropy of the battery.
  • the present invention proposes a method for calculating a change in temperature of a battery according to the initial temperature and SOC of the battery by applying the measured entropy of the battery to the mathematical formula summarized with respect to the thermochemical characteristics of the battery.
  • the present invention proposes a method capable of deriving the open circuit voltage, internal resistance, entropy, and specific heat, which are intrinsic characteristics of the battery, according to the state of charge (SOC).
  • SOC state of charge
  • the present invention proposes a method capable of calculating (predicting) voltage / current / temperature changes for a short circuit of a battery by using open circuit voltage, internal resistance, entropy, and specific heat, which are inherent characteristics of the battery.
  • FIG. 1 is a flowchart illustrating a method for measuring entropy through cooling of a battery according to an embodiment of the present invention.
  • the battery is charged or discharged with a predetermined SOC (STATE OF CHARGE) (S410). Since it is necessary to reveal the thermochemical characteristics according to the SOC of the battery, the target SOC of the battery is set in advance and then the battery is charged or discharged as much as the preset SOC to reach the target SOC.
  • the target SOC of the battery may be an SOC having a predetermined interval between 0 and 1.
  • the target SOC may be set in 0.05 units in a section between 0 and 1.
  • the method may further include heating the battery to a predetermined temperature. Heating of the battery may be performed within a range in which the battery is not damaged, for example, by heating the temperature of the battery to 60 ° C, a sufficient incubation time may be given so that the battery reaches a thermal equilibrium state.
  • the battery When the battery reaches a predetermined SOC, the battery is cooled (S420).
  • the cooling of the battery can be gradually and gradually cooled to obtain various temperature and voltage data, and it is desirable to gradually cool the heated battery at room temperature until a thermal equilibrium state is reached.
  • the cooling of the battery may be gradually cooled naturally in an adiabatic state.
  • the adiabatic state assumes an ideal perfect adiabatic state, but in reality, since a completely adiabatic state cannot exist, it can be naturally cooled in environmental conditions close to adiabatic.
  • physicochemical information of the battery is collected (S430).
  • the battery's physicochemical information it may be a battery temperature and an open circuit voltage (OCV).
  • the entropy of the battery is calculated using the measured battery temperature and the open circuit voltage (S440).
  • the entropy of the battery can be calculated by Equation 1 below.
  • S is the entropy
  • O CV is the open circuit voltage
  • T is the temperature
  • n is the number of moles of electrons moving in the cell reaction
  • F is the Faraday constant of 96,500 C / mol.
  • the processes of S410 to S440 can be repeated to calculate the entropy of the battery under different SOC conditions. .
  • the physicochemical properties of the battery under various SOC conditions can be measured, and the entropy of the battery can be calculated using the measurement data.
  • Gibb's energy refers to the amount of 'usable' energy in a chemical system. In the case of batteries, this energy can be converted into electricity. Therefore, the Gibbs energy is the amount of main power of the electric charge present in the battery at a given moment multiplied by the voltage of the battery at that moment. That is, in the case of a battery, Gibbs energy is determined by the following relationship.
  • Equation (6) can be substituted as follows.
  • enthalpy H represents the total amount of energy in the system, that is, the sum of usable energy and non-usable energy (potential energy, if any, including kinetic energy). In the case of batteries, there is no external force, so the system can result in a thermo-chemical analysis.
  • Equation 1 can be obtained by differentiating Equation 5 with respect to the temperature T, and then arranging it with respect to the entropy S.
  • the end temperature of the battery after the constant current charging or the constant current discharge of the battery with respect to the initial temperature of the battery before the constant current charging or the constant current discharge of the battery may be derived by Equation (6) including the entropy.
  • T n-1 is the initial temperature (K, °C) of the calculation step in the battery charge or discharge conditions
  • T n is the end temperature of the calculation step (K, °C) in the battery charge or discharge conditions
  • M is the battery mass (g)
  • Cp is the specific heat of the battery (J / gK or Wh / gK)
  • I is the battery current (A, discharge (+), charge (-))
  • C is the charging current value for the battery capacity (q 0 )
  • q 0 is the battery capacity (Ah, 3600coulomb (Asec)
  • (R i (n-1) ) is given SOC and given temperature
  • the battery internal resistance (ohm, ⁇ ) corresponding to, ⁇ S average (n-1, n) is the average battery entropy of the initial ⁇ SOC section ⁇ S n-1 and the final SOC section ⁇ S n (J / mol.
  • C is a ratio (I / q 0 ) of a charging current value to a battery capacity, and when C is 1, it corresponds to a current value in which the battery is fully charged from SOC 0 to SOC 1 in one hour. When C is 2, it corresponds to a current value in which the battery is fully charged from SOC 0 to SOC 1 in 1/2 hour (30 minutes).
  • Equation 7 shows the relationship between the amount of heat generated and the temperature increase according to constant current charging or constant current discharge of the battery.
  • Equation 8 When the internal resistance of the battery and the entropy are combined in the heat generation of the constant current state of the battery in Equation 7, Equation 8 below is derived.
  • Equation 9 the elapsed time in the constant current state is a primary function of the SOC of the battery, and in Equation 10, the derivative time can be applied in the relationship of the derivative SOC, and in Equation 11, the current I is the charging current for the battery capacity. It can be defined in terms of the ratio of values C. Then, in Equation 12, the relationship between the calorific value Q and temperature is summarized.
  • Equation (13) Equation (13) below, and arranging them with respect to temperature results in Equation (6).
  • the battery internal resistance (R i ) according to the battery SOC can be derived by using the experimentally measured battery current, open circuit voltage and temperature.
  • the internal resistance of the battery can be calculated by a well-known conventional technique.
  • C p battery heat capacity
  • a device for measuring the heat capacity of the battery may be used.
  • specific heat and heat capacity of the battery may be measured by an adiabatic thermal analysis equipment (ARC).
  • ARC adiabatic thermal analysis equipment
  • the internal resistance and entropy of the battery can be calculated by measuring the temperature, current, and open circuit voltage according to the SOC of the battery by the entropy measurement method by cooling the battery described above, and specific physical heat, heat capacity, mass, etc. of the battery
  • the temperature change of the battery can be calculated by calculating the characteristics of.
  • the predetermined initial SOC and the final SOC section are automatically divided and the temperature change of the battery can be calculated by repeating the same process sequentially in the divided section.
  • the number of battery SOC divisions was set to 1000 to perform sequential iterations, and as a result, good results were obtained with respect to calculation of battery thermochemical characteristics and calculation of battery temperature change.
  • thermochemical characteristic value relating to the initial condition of the battery may be input to Equation (6).
  • thermochemical characteristic values related to the initial conditions of the battery are measured through an entropy measurement method through cooling of the battery, and are calculated using the measured values, such as temperature, current, open circuit voltage, and internal resistance of the battery. , Heat capacity, weight, specific heat, entropy, and the like.
  • T 2 may be obtained by applying Equation (6) to the first SOC period among the divided SOC periods.
  • a temperature change may be calculated for the divided second SOC section by inputting the result value calculated in the divided first SOC section again as an input value of Equation (6).
  • the T 2 value calculated in the first divided SOC section may be input again as a new value of T 1 in the second divided SOC section, and a new interior in the second section divided into the new T 1 value.
  • the resistance can be calculated, and a new T 2 value in the second divided section can be calculated using the new T 1 and the new internal resistance.
  • FIG. 5 is a graph showing an open circuit voltage of a battery in charging and discharging for each SOC of a battery for a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention.
  • the open circuit voltage of the battery was measured while charging or discharging the battery for each temperature within the SOC 0 to 1 range of the battery.
  • FIG. 6 is a diagram illustrating the change in battery voltage for each temperature by moving the result of FIG. 5 at 0.5V intervals.
  • the open circuit voltage for each SOC of the battery according to charging and discharging of the battery at a battery temperature of 18, 25, 40, 55, and 60 degrees Celsius is illustrated at 0.5V intervals. In the range of the battery SOC 0.05 to 1, the voltage changes between charging and discharging are almost similar.
  • 7 to 8 are diagrams showing open circuit voltage information according to battery SOC according to the temperature of the battery during battery charging and discharging.
  • 9 to 10 are diagrams showing a polynomial relationship of open circuit voltage information according to battery SOC for each battery temperature during battery charging and discharging.
  • the open circuit voltage of the battery for each temperature may be expressed as a quadratic function relationship of the battery SOC.
  • the OCV relationship of the batteries shown in FIGS. 5 to 10 is used as important information in the analysis of the electro-thermochemical characteristics of the battery in the case of constant voltage charging and discharging, constant output charging and discharging, and resistance discharge, but in the present invention, constant current charging Since the discharge battery is analyzed as an example of a battery that is charged and discharged at a constant current, the data is not used.
  • FIG. 11 shows the internal resistance of the battery against the battery SOC at absolute temperatures of 298K, 313K, and 328K when charging or discharging the battery in the entropy measurement method by cooling the battery according to an embodiment of the present invention and the battery temperature change calculation method using the method. It is a drawing shown.
  • FIG. 11 a battery temperature change for a battery SOC and a battery internal resistance for each battery SOC during battery charging and discharging are illustrated.
  • the left Y-axis shows resistance
  • the right Y-axis shows temperature.
  • 12 to 13 is a battery for a battery SOC at a temperature condition of 298K, 313K, 328K during battery charging and discharging in a method for measuring entropy through cooling of a battery according to an embodiment of the present invention and a method for calculating a change in battery temperature using the method It is a diagram showing the internal resistance value.
  • the battery internal resistance value is calculated using the current and voltage values by measuring the current and open circuit voltage of the battery to the battery SOC at 298K, 313K, and 328K temperature conditions during charging and discharging of the battery. Therefore, it is plotted as a natural logarithmic scale.
  • FIG. 14 is a diagram illustrating a change in the average internal resistance of a battery according to temperature in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention.
  • the battery average internal resistance according to battery temperature conditions (298K, 313K, and 328K) is calculated and illustrated, and the average internal resistance according to temperature uses a result for an SOC section in which the change in battery internal resistance is small. was derived.
  • the relationship of the average internal resistance to temperature was calculated by Equations 14 to 15.
  • E is the battery open circuit voltage
  • K is the absolute temperature
  • R is in ohms.
  • 15 is a diagram illustrating a battery internal resistance value for SOC by temperature during charging and discharging of a battery in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention.
  • the internal resistance according to the SOC with a small change in the internal resistance of the battery is calculated and illustrated at some temperatures 298K, 313K, and 328K during battery charging and discharging.
  • 16 to 18 are graphs for measuring specific heat of a battery in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention.
  • a temperature change of a battery may be measured by controlling a constant heating power and a heating time for a resistance heating element located between two batteries, and a specific heat of the battery may be analyzed by analyzing a relationship between temperature changes of the battery according to the time change Can be measured.
  • 19 to 21 is a battery over time when gradually cooling a battery heated to 60 ° C. while being charged or discharged with a predetermined battery SOC in an entropy measurement method through cooling of the battery according to an embodiment of the present invention.
  • This graph shows changes in temperature and open circuit voltage.
  • a sufficient incubation time can be set so that the battery reaches a thermal equilibrium state by heating the temperature of the battery to 60 ° C. within a range in which the battery is not damaged. Thereafter, in the process of gradually cooling the battery at room temperature, the temperature change and the open circuit voltage change of the battery were measured and plotted over time. Using this method, it is possible to continuously measure the temperature change and the open circuit voltage change for each SOC of the battery, and the internal temperature fluctuation of the battery is reduced, so that accurate measurement data can be obtained.
  • T is a battery temperature
  • V is a battery open circuit voltage
  • t is time
  • 22 to 23 are graphs showing a change in the battery open circuit voltage with respect to the temperature change from the relationship between the battery temperature change and the open circuit voltage with time shown in FIGS. 19 to 21.
  • the result of FIG. 19 is converted into a relationship between the temperature of the battery and the open circuit voltage, and is illustrated in a graph.
  • the open circuit voltage does not appear to be a linear function of temperature, but considering the scale of the open circuit voltage of the battery, the battery open circuit voltage can be viewed as a first order function of temperature change.
  • the data in FIG. 22 is expressed by an equation, where T is a battery temperature and V is a battery open circuit voltage.
  • FIG. 24 is a diagram illustrating a battery open circuit voltage for a battery temperature measured by a battery adiabatic low-speed cooling method for each battery SOC section set in a method for measuring entropy through cooling of a battery according to an embodiment of the present invention.
  • the battery open circuit voltage according to the temperature change in various battery SOC conditions is illustrated. Considering the battery voltage scale, despite the temperature change, the change in the open circuit voltage of the battery is not large and the battery SOC Therefore, it can be seen that the open circuit voltage increases or decreases according to the temperature of the battery.
  • 25 is a diagram illustrating an example in which entropy is calculated by a method of measuring entropy through cooling of a battery according to an embodiment of the present invention.
  • the battery entropy formula can be used to derive the battery entropy.
  • 26 to 27 are battery entropy values having a temperature change between 60 ° C and 30 ° C according to a prior art battery entropy measurement method and batteries having a temperature change between 60 ° C and 20 ° C according to a battery entropy measurement method of the present invention. It is a diagram showing a comparison of an entropy value and a battery entropy value having a temperature change between 60 ° C and 20 ° C according to the entropy generation method of the present invention.
  • a battery having a higher battery entropy value according to the battery entropy measurement method of the present invention is compared with an entropy measurement value according to an open circuit voltage measurement method by discrete stepping of temperature, which is a battery entropy measurement method of the prior art It has the representativeness of the entropy value.
  • the battery entropy value according to the method for generating entropy of the present invention has a value substantially similar to the battery entropy value according to the method for measuring battery entropy of the present invention.
  • FIG. 28 is a diagram illustrating a battery entropy value according to a battery SOC by the battery entropy measurement method of the present invention divided into four sections.
  • the battery entropy value according to the battery SOC according to the battery entropy measurement method of the present invention is one over the entire SOC Defining it in this way is so complex that it is difficult in reality. Therefore, it can be divided into four operation regions of the first region to the fourth region to define expressions for the battery entropy values for each region.
  • the first region is a region of SOC 0 to 0.1, and the entropy has a negative number and may be represented by a linear relationship according to SOC.
  • the second region is a region of SOC 0.1 to 0.28, and the entropy has a negative number and tends to increase with SOC and shows a result close to a linear relationship.
  • the third region is SOC 0.28 to 0.57 (5), and the entropy has a positive number. According to the experimental results, the entropy value in the third region should have opposite signs from the first region and the second region. In this regard, it can be confirmed that the entropy measured by the battery entropy measurement method according to the present invention is close to the actual phenomenon.
  • the fourth region is a region of SOC 0.57 (5) to 1, and the entropy represents a negative number, and a section having five inflection points with low significance can be integrated into one region and represented by a six-dimensional polynomial function.
  • 29 is a diagram illustrating an entropy polynomial according to a battery SOC region according to a method for measuring battery entropy according to the present invention.
  • entropy in the first region, entropy may be expressed as a first order function for SOC, in the second region, entropy may be expressed as a second order function for SOC, and in the third region, entropy may be expressed by SOC. It can be expressed as a third-order function for, and in the fourth region, entropy can be expressed as a sixth-order function for SOC.
  • FIG. 30 is a graph showing temperature changes for each location of a battery and a battery chamber during battery adiabatic discharge in a method for measuring entropy through cooling of a battery and a method for calculating a change in battery temperature using the battery according to an embodiment of the present invention.
  • 31 to 33 illustrate battery temperatures and voltages during adiabatic charging and discharging using battery characteristics measured according to an entropy measurement method through cooling of a battery according to an embodiment of the present invention and a method for calculating a change in battery temperature using the method It is a graph.
  • the battery voltage shows similar characteristics without a large change according to the progress of charging and discharging.
  • the battery temperature tends to increase overall as charging and discharging progress.
  • the temperature increases rapidly, and then the temperature increase tends to slow down.
  • exothermic and endothermic reactions appeared together during charging and discharging.
  • the SOC boundary of the battery with changes in heat and endothermic tendencies was roughly identified and represented by a red line. It can be seen that the division of the region almost coincides with the boundary of the four entropy regions illustrated in FIG. 28.
  • the temperature for each battery SOC calculated by applying the heat capacity, entropy, internal resistance, specific heat, and weight of the battery is also shown.
  • SOC 0.1 to 1.0 region where the battery entropy and internal resistance exhibited stable changes, a meaningful calculation result with a tendency similar to the value measured by actual experiments was found.
  • SOC 0.0 to 0.1 region of the battery calculation results with a large difference from the experimental measurement results were found. In the SOC 0.0 to 0.1 region, it can be interpreted that this is because the stability of the calculation is lowered due to a large change in battery entropy and internal resistance.
  • each is a result of measuring the battery temperature and the open circuit voltage according to the battery charging and discharging of C 0.3 and C 0.5 by actual experiment, and the heat capacity, entropy, internal resistance, specific heat, and weight of the battery
  • the temperature by battery SOC calculated by applying is also shown. It can be seen that the calculated result value and the measured experimental value have very similar values not only at C 0.05 but also at C 0.3 and C 0.5. This matching tendency means that the calculation method of thermochemical characteristics such as entropy, specific heat, and internal resistance is very accurate.
  • 31 is a flow chart illustrating a method for deriving a unique characteristic of a battery according to an embodiment of the present invention.
  • the state of charge (SOC) of the battery is adjusted to 0 by completely discharging the battery (S111).
  • S111 state of charge
  • current, voltage, and temperature of the battery according to changes in time are measured, and the measured data is stored in a database (or memory) (S112).
  • the voltage of the battery is the open circuit voltage (Open Circuit Electromotive Force, E OC ).
  • the target SOC of the battery After charging or discharging the battery to a predetermined target state of charge (SOC), it is maintained for a predetermined period of time (S121). Since the thermochemical characteristics according to the state of charge (SOC) of the battery need to be revealed, the target SOC of the battery is set in advance and then the battery is charged or discharged as much as the predetermined SOC to reach the target SOC.
  • the target SOC of the battery may be an SOC having a predetermined interval in a section between 0 and 1.
  • the target SOC may be set in 0.05 units in a section between 0 and 1.
  • the current, voltage, and temperature of the battery according to time change are measured, and the measured data is stored in a database (S122). Thereafter, the open circuit voltage (E OC ) and the internal resistance of the battery according to the current SOC state may be derived based on the data stored in the database (S123).
  • the internal resistance of the battery can be calculated based on the open circuit voltage, closed circuit voltage (Closed Circuit Electromotive Force, E CC), current and temperature of the battery according to the current SOC.
  • the battery After charging the battery with a predetermined target SOC, the battery is heated to a predetermined temperature using a heating element (S131).
  • the heating of the battery may be performed within a range in which the battery is not damaged, for example, by heating the temperature of the battery to 60 ° C., a sufficient constant temperature time may be given so that the battery reaches a thermal equilibrium state.
  • the specific heat of the battery may be derived by analyzing the relationship of the temperature change of the battery with the change of time through the specific heat measuring device (S133). For example, a specific heat (or heat capacity) of a battery may be measured using an adiabatic thermal analysis equipment (ARC). In addition, the specific heat of the battery may be calculated using well-known techniques.
  • ARC adiabatic thermal analysis equipment
  • the battery When the battery reaches a predetermined target SOC, the battery is cooled (S141).
  • the cooling of the battery can be gradually and gradually cooled to obtain various temperature and voltage data, and it is preferable to gradually cool the heated battery at room temperature until a thermal equilibrium state is reached. Further, the cooling of the battery may be gradually cooled naturally in an adiabatic state.
  • the adiabatic state assumes an ideal perfect adiabatic state, but in reality, since a completely adiabatic state cannot exist, it can be naturally cooled in environmental conditions close to adiabatic.
  • the entropy of the battery is calculated using the measured temperature and voltage (E OC ) of the battery (S143). For example, the entropy of the battery may be calculated by Equation 16 below.
  • ⁇ S is entropy
  • E OC open circuit voltage
  • T temperature
  • n the number of electrons moving in the cell reaction
  • F Faraday's constant of 96,500 C / mol.
  • the open circuit voltage, internal resistance, specific heat and entropy of the battery are calculated from the target SOC of the battery, the battery is charged or discharged to the next target SOC of the battery, and then the above steps S121 to S143 are repeated.
  • the open circuit voltage, internal resistance, specific heat and entropy at the next target SOC can be calculated.
  • the charge upper limit voltage or the discharge lower limit voltage of the battery is reached (S150)
  • the process of deriving the unique characteristics (ie, open circuit voltage, internal resistance, specific heat and entropy) of the battery according to the preset SOC state is terminated. do.
  • 32A is a diagram schematically showing a short circuit equivalent circuit of a corresponding battery when the battery is short-circuited.
  • the short circuit equivalent circuit 100 of the battery is a battery voltage (V), internal resistance (R i ), load resistance (R L ) and line resistance (R w ) Includes.
  • the battery may include a safety device such as a fuse. Accordingly, in the case of a short circuit of the battery, when the internal temperature of the battery rapidly increases, a fuse inside the battery automatically operates to safely protect the battery. Based on such a short circuit equivalent circuit of a battery, a method for analyzing voltage / current / temperature changes for a short circuit of the battery will be described.
  • 32B is a diagram schematically showing a process in which the battery generates heat when the battery is short-circuited.
  • Equation 17 can be used to predict the temperature change of a battery that cannot be physically measured very closely.
  • T n-1 represents the initial temperature (K, °C) of the calculation step in the short circuit condition of the battery
  • T n the termination temperature (K, °C) of the calculation step in the short circuit condition of the battery
  • M represents the mass (g) of the battery
  • C p is the specific heat ( ).
  • q 0 represents the capacity (Ah) of the battery.
  • R i represents the internal resistance (ohm) of the battery corresponding to the given SOC and temperature
  • E OC represents the open circuit voltage (V OC ) of the battery corresponding to the given SOC and temperature.
  • R L represents the load resistance (ohm)
  • R w represents the line resistance (ohm).
  • ⁇ SOC (dSOC) represents the derivative value of SOC, and F represents the Faraday constant (C / mol).
  • the subscript n-1 represents the initial stage of the corresponding computational step, and the subscript n represents the termination stage of the corresponding computational step.
  • ⁇ S avg (n, n-1) is the average molar entropy of the battery corresponding to the initial SOC ( ⁇ S n-1 ) and the final SOC ( ⁇ S n ) in the ⁇ SOC interval, as shown in Equation 18 below. ).
  • Equations 17 and 18 the temperature change for the short circuit of the battery can be calculated (predicted) according to the differential charge state (dSOC).
  • dSOC differential charge state
  • Equation 19 below shows a formula summarizing the calorific value Q according to the short circuit of the battery.
  • Equation 20 is a function that summarizes SOC of a battery using the capacity, current, and time of the battery
  • Equation 21 below is a function obtained by differentiating Equation 20 above.
  • Equation 22 below is a function that summarizes the current I using the open circuit voltage, internal resistance, load resistance, and line resistance of the battery
  • Equation 23 below is a function that summarizes the relationship between the calorific value Q and temperature. to be.
  • Equation 17 described above is derived.
  • E OC open circuit voltage
  • R i internal resistance
  • C p specific heat
  • ⁇ S entropy
  • the load resistance R L is close to the positive resistance, but the internal resistance of the battery, the open circuit voltage, the closed circuit voltage, and the current are changed depending on the charging state (SOC) due to the temperature change due to the heat generation of the battery. It is a complex change.
  • This complex change relationship is expressed in Equation 17 above. It can be expressed as an item of Equation 17.
  • the specific heat of the battery is small and the change according to the SOC (SOC) can be seen as a constant, but E OC , R i , ⁇ S and the battery's SOC (SOC) It has a complex function relationship that varies with temperature.
  • Equation 17 From the relationship of Equation 17 described above, it is possible to calculate the temperature change for each micro section and the entire SOC section based on the given load resistance R L , line resistance R W , and initial temperature.
  • Equation (25) the temperature change for each minute section and the total SOC section from the given load resistance (R L ), line resistance (R W ), and initial temperature
  • the change of the open circuit voltage (E OC ) and the closed circuit voltage (E CC ) for can be calculated.
  • Equations 26 and 27 above are equations representing the relationship between ⁇ SOC (dSOC) and time, and the relationship between the current, open circuit voltage, closed circuit voltage, and temperature of the battery obtained above is the change of SOC or time. You can freely express it as you change.
  • the temperature change, the change in current, the change in the open circuit voltage, and the change in temperature for each minute SOC section and the entire SOC section from the load resistance, line resistance, and initial temperature given from the above equations (17, 24, 25) Changes in circuit voltage can be calculated.
  • the relationship between the change of temperature, the change of the current, the change of the open circuit voltage, and the change of the closed circuit voltage can be freely expressed according to the change of SOC or the change of time from the relational expressions of Equations 26 and 27 described above.
  • the intrinsic characteristics (open circuit voltage, internal resistance, specific heat and entropy) according to the state of charge (SOC) of the battery to be shorted are derived, and the voltage / current for the short circuit of the battery is derived by using the intrinsic characteristics of the derived battery. / Explain how to predict temperature changes in more detail.
  • 33A is a block diagram of an apparatus for predicting a short circuit of a battery according to an embodiment of the present invention.
  • a battery short circuit characteristic prediction device 300 includes a battery characteristic detection unit 310, a temperature change prediction unit 320, a voltage change prediction unit 330, and a current change prediction unit. 340 may be included.
  • the battery characteristic detection unit 310 may detect unique characteristic information according to a state of charge (SOC) of the battery.
  • SOC state of charge
  • the unique characteristic information is a value that varies depending on the state of charge (SOC) of the battery, and may include information about the open circuit voltage, internal resistance, specific heat and entropy of the battery.
  • the battery characteristic detector 310 may be provided with input parameter information related to a battery short circuit.
  • the input parameter information is a fixed value that does not vary depending on the state of charge (SOC) of the battery, and may include information about the capacity, mass, load resistance, and line resistance of the battery.
  • the temperature change predicting unit 320 may predict a temperature change for a short circuit of a corresponding battery by using the characteristic information and input parameter information of the battery. At this time, the temperature change predicting unit 320 may predict a temperature change for a short circuit of the battery using a relational model (ie, Equation 17) modeled through heat generation analysis of the battery.
  • a relational model ie, Equation 17
  • the voltage change predicting unit 330 may predict a voltage change for a short circuit of a corresponding battery by using the characteristic information and input parameter information of the battery. In this case, the voltage change predicting unit 330 may predict the voltage change for the short circuit of the battery using Equation 25 described above.
  • the voltage to be predicted includes an open circuit voltage and a closed circuit voltage.
  • the current change predicting unit 340 may predict a current change for a short circuit of the corresponding battery using information about the characteristic characteristics of the battery and input parameter information. At this time, the current change predicting unit 340 may predict the current change for the short circuit of the battery using Equation 24 described above.
  • 33B is a flowchart illustrating a method of predicting a short circuit characteristic of a battery according to an embodiment of the present invention.
  • the battery short-circuit prediction apparatus may derive information on the unique characteristics of the battery (S310).
  • the apparatus for predicting battery short-circuit characteristics may call unique characteristic information of a battery previously stored in a memory.
  • the battery short circuit characteristics predicting device derives the open circuit voltage, internal resistance, specific heat and entropy of the battery by measuring the voltage, current and temperature according to the SOC of the battery to be shorted based on the measurement method described in FIG. 31. can do.
  • the battery short circuit characteristic prediction apparatus may be provided with input parameter information related to a short circuit of the battery.
  • the input parameter information may include information about the capacity, mass, load resistance, and line resistance of the battery.
  • the battery short-circuit characteristic predicting apparatus may automatically divide a predetermined initial SOC and a final SOC section (S320).
  • the apparatus for predicting short circuit characteristics of a battery may set the SOC division number of the battery to 1000.
  • the battery short circuit characteristic prediction device may calculate a temperature change for a short circuit of the battery for each SOC section (S330).
  • the battery short circuit characteristic prediction apparatus may input the input parameter information regarding the initial condition of the short circuit of the battery into Equation 17 described above.
  • the input parameter information may be an initial temperature, capacity, mass, load resistance and line resistance of the battery.
  • the apparatus for predicting a battery short-circuit characteristic may input the open circuit voltage, internal resistance, specific heat, and entropy according to the state of charge (SOC) of the battery in Equation 17 to calculate a temperature change for a short circuit of the battery for each SOC section.
  • the battery short circuit characteristic prediction apparatus calculates the average entropy for the section between the initial SOC and the final SOC, and divides the section between the initial SOC and the final SOC into a predetermined number of divisions to the SOC of each divided section.
  • the temperature change value (T 2 ) of the corresponding SOC section can be obtained by applying Equation 17 to the first SOC section among the divided SOC sections.
  • the battery short circuit characteristic prediction apparatus may calculate (predict) voltage and current changes for a short circuit of a battery in a corresponding SOC period using Equations 24 and 25 described above.
  • the apparatus for predicting a battery short circuit characteristic may determine whether a final SOC period is reached (S340).
  • the battery short circuit characteristic predicting device may move to the next SOC section and calculate a temperature change for the short circuit of the battery (S350).
  • the battery short circuit characteristic prediction apparatus may calculate a temperature change for the second SOC section that is divided by inputting the result value T 2 calculated in the first SOC section that is divided as an input value of Equation 17 again.
  • the temperature change value T 2 calculated in the divided first SOC section may be input again as a new input value in the divided second SOC section, and a new open circuit voltage in the divided second section.
  • Internal resistance, specific heat and entropy can be calculated
  • new temperature change value (T 3 ) in the divided second section can be calculated using the new open circuit voltage, internal resistance, specific heat and entropy.
  • the battery short circuit characteristic prediction apparatus may calculate (predict) voltage and current changes for the short circuit of the battery in the following SOC period using Equations 24 and 25 described above.
  • 34A to 34C are graphs showing actually measured voltage / current / temperature changes of a corresponding battery according to a change in the size of a load resistance during a short circuit of the battery.
  • FIG. 34A is a graph actually measuring voltage / current / temperature changes for a short circuit of a battery when the load resistance is Om ⁇ .
  • a lithium ion battery (3.6V, 103Ah) was charged with SOC 100% and fastened with an electronic external short circuit with a line resistance of 0.91m ⁇ to form a short circuit cell having an external resistance of 0.91m ⁇ in total.
  • the open circuit voltage of the battery was measured as 4.09V
  • the closed circuit voltage and current of the battery immediately after the short circuit were measured as 2.17V and 1,044A, respectively, and the maximum current and closed circuit voltage were 1,634A at 174ms. And 1.57V.
  • the surface temperature of the battery measured by the thermocouple increased from the initial average temperature of 20.25 ° C to the maximum average temperature of 27.27 ° C from 68 seconds of elapsed time.
  • the measurement time interval was 1 ms.
  • the time difference between the highest current and the highest temperature is due to the difference in time it takes for the heat generated between the electrodes to transfer to the cell surface.
  • Temp. Showing the position of the thermocouple in FIG. 34A.
  • x denotes the x-axis from 0 to 1, starting from the end of the anode terminal to the end of the cathode terminal in a rectangular cell with a thin stack of electrode plates
  • y is the far end of the electrode terminal. It is the expression showing the y-axis from 0 to 1 starting from the end of the electrode terminal.
  • Temp. (0.5,0.5) represents the thermocouple temperature at the center of the cell. During the elapsed time, the temperature of the (+) and (-) electrode terminals was almost unchanged, the temperature at the center was the highest, and the temperature at the far side from the electrode terminal was lower than the center.
  • Fig. 34B is a graph actually measuring voltage / current / temperature changes for a short circuit of a battery when the load resistance is 2 m ?.
  • a lithium ion battery (3.6V, 103Ah) was charged with SOC 100% and fastened with an electronic external short circuit with a line resistance of 0.91m ⁇ to construct a short circuit cell having an external resistance of 2.91m ⁇ in total.
  • the open circuit voltage of the battery was measured to be 4.09 V as shown in Fig. 34A.
  • the maximum current was measured at 2.41 V and 940 A, respectively, of the closed circuit voltage and current of the battery.
  • the surface temperature of the battery measured with a thermocouple was measured at an initial average temperature of 20.2 ° C and a maximum average temperature of 116.42 ° C at an elapsed time of 548 seconds (9 minutes and 8 seconds).
  • the maximum temperature is the Temp. (0.174, 0778), the elapsed time was measured from 9 minutes 1 second to 191.92 ° C.
  • Temp. On the negative electrode terminal side. (0.826, 0778) was measured from 8 minutes 45 seconds to 146.71 ° C. The distance from the center and terminal of the battery showed a modest increase in temperature.
  • the highest temperature measured at the cell surface was measured from 541 seconds to 191.92 ° C, indicating that the internal temperature of the cell was higher than 191.92 ° C at the time of 360 seconds when the current was continuously high.
  • the very important fact that can be drawn from the conclusion is that the battery of the experiment showed a very high stability due to the heat dissipation gradually without causing the internal short circuit by the fuse despite the surface temperature of the battery rising to 191.92 °C due to the external short circuit. have.
  • FIG. 34C is a graph actually measuring voltage / current / temperature changes for a short circuit of a battery when the load resistance is 5 m ⁇ .
  • a lithium ion battery (3.6V, 103Ah) was charged with SOC 100% and fastened with an electronic external short circuit with a line resistance of 0.91m ⁇ to form a short circuit battery circuit having a total external resistance of 5.91m ⁇ .
  • the open-circuit voltage of the battery was measured to be 4.09 V as shown in FIGS. 34A and 34B.
  • the maximum current was measured with the closed circuit voltage and current of the cells as 2.787V and 735A.
  • a flat current and voltage section was displayed until the elapsed time of about 610 seconds, and the average current and voltage were measured to be 390A and 2.937V. It is measured that the current and voltage rapidly decrease at the elapsed time of 610 seconds (that is, 10 minutes and 10 seconds), so that the intense discharge is terminated at the elapsed time of about 650 seconds (that is, 10 minutes and 50 seconds) and the residual residual discharge continues. Became.
  • the surface temperature of the battery measured with a thermocouple was measured at an initial average temperature of 18.6 ° C and a maximum average temperature of 70.23 ° C. The highest temperatures were measured at 88.26 ° C and 79.91 ° C, respectively, at the (+) and (-) electrode terminals.
  • 35A and 35B are graphs showing a change in voltage / current / temperature of a battery according to time or SOC calculated based on a predefined equation for a short circuit of a battery according to an embodiment of the present invention to be.
  • the short-circuit battery circuit according to the present embodiment is a short-circuit battery circuit having an external resistance of 0.91 m ⁇ in total, and is the same as the configuration of the short-circuit battery circuit of FIG. 34A described above. Therefore, FIGS. 35A and 35B are the results of calculation by thermochemical modeling for the short circuit of FIG. 34A.
  • thermochemical modeling generates heat by applying the open circuit voltage, entropy, and internal resistance derived from the functional relationship with respect to the state of charge and temperature with respect to the equation 17 of the present invention and the lithium ion battery (3.6 V, 103 Ah) subject to an external short circuit. It is a result of calculating the amount of heat absorption and applying the specific heat relationship of the corresponding battery according to the time change so that the relationship between voltage, current and temperature can be compared with the graph of FIG. 4A.
  • the initial current of the short-circuit battery and the battery voltage at this time were calculated to be 1,265A and 1.15V, respectively, compared to the values measured in FIG. 34A (ie, 1,044 A, 2.17V). It can be seen that the results are close. If the short circuit continues under the condition that the battery safety device, the fuse, does not operate, the current and voltage forming the flat area were calculated to be 2kA and 1.8V. The internal resistance of the heating furnace is lowered, resulting in an increase in the voltage and current of the battery even during discharge. The intense discharge was terminated at an elapsed time of about 160 seconds, and the residual discharge proceeded from the elapsed time of about 200 seconds. And, it was calculated that the temperature increased up to 184 ° C in the short circuit starting at the initial temperature of 20 ° C.
  • 36A and 36B are graphs showing a change in voltage / current / temperature of a battery according to time or SOC calculated based on a predefined equation for a short circuit of a battery according to another embodiment of the present invention. to be.
  • the short-circuit battery circuit according to this embodiment is a short-circuit battery circuit having an external resistance of 2.91 m ⁇ in total, which is the same as the configuration of the short-circuit battery circuit of FIG. 34B described above. Accordingly, FIGS. 36A and 36B are the results calculated by thermochemical modeling for the short-circuit cell circuit of FIG. 34B.
  • the initial current of the short-circuit battery and the battery voltage at this time were calculated to be 785A and 2.28V, respectively.
  • the current and voltage forming the flat area were calculated to be 950A and 2.78V.
  • the average current in FIG. 34B which is an experimental result, was 620A, and the voltage was measured to be 2.4V. It was calculated that the intense discharge ended at an elapsed time of about 350 seconds, and the residual discharge proceeded from an elapsed time of about 410 seconds. It was calculated that the temperature increased up to 110.5 ° C with a short circuit starting at the initial temperature of 20 ° C. It can be seen that the calculation results of the intense discharge duration, current, and maximum reaching temperature are close to the experimental results.
  • the difference between the experimental results of FIG. 34B and the thermal chemistry calculation results using the predefined equations is that the calculation of the first heat transfer is not considered, and the second open-circuit voltage and internal resistance sufficiently depend on temperature.
  • the point that is not considered and the change in the open circuit voltage with respect to the third temperature is a strictly nonlinear relationship, but in order to interpret it based on the ordinary scientific understanding, it is summarized by the entropy value represented by the existing thermodynamic relational equation, and the equation is expressed in a linear relationship. This is because it was developed.
  • the accuracy of the temperature change calculation can be improved by applying all practical relationships of the open circuit voltage change to temperature.
  • 37A and 37B are graphs showing voltage / current / temperature changes of a battery according to time or SOC calculated based on a predefined equation for a short circuit of a battery according to another embodiment of the present invention. It is a drawing.
  • the short-circuit battery circuit according to the present embodiment is a short-circuit battery circuit having an external resistance of 5.91 m ⁇ in total, and is the same as the configuration of the short-circuit battery circuit of FIG. 34C described above. Accordingly, FIGS. 37A and 37B are the results calculated by thermochemical modeling for the short-circuit cell of FIG. 34C.
  • the initial current of the short-circuit cell and the cell voltage at this time were calculated to be 495A and 2.927 V, respectively.
  • the current and voltage forming the flat area were calculated to be 527A and 3.11V, respectively.
  • the average current in FIG. 34C an experimental result, was 390 A, and the voltage was measured 2.937 V. It was calculated that the intense discharge ended at an elapsed time of about 620 seconds, and the residual discharge proceeded at an elapsed time after 780 seconds.
  • a short circuit starting at an initial temperature of 18.4 ° C was calculated to increase the temperature up to 84.43 ° C.
  • FIG. 38 is a graph showing a result of calculating a current change for a short circuit of a battery according to various conditions. That is, FIG. 38 is a graph showing the result of calculating the change in current according to the external short-circuit resistance over time by applying the above-described Equation 17 and the characteristic values of the corresponding battery.
  • the external resistances are 0.91, 2.91, 5.91, 20.91, 30.91, and 150.91 m ⁇ , and the results of applying entropy and internal resistance as initial values or when applying them as function values are shown in complex.
  • the maximum current was initially calculated to be the highest 26.95 A, after which it continued to decrease.
  • Table 1 below is a table showing the short circuit termination time and temperature depending on whether entropy and internal resistance change are applied in a short circuit cell having an external resistance of 150.91 m ⁇ .
  • Table 1 when the internal resistance was used as the initial value, the short-circuit termination temperature was slightly lower than when the internal resistance was applied as the change value for temperature. The low contribution due to the presence or absence of internal resistance is due to the low temperature change of the battery as a whole.
  • the short-circuit termination temperature was about 3 ° C higher than when the change of entropy was not applied.
  • Short circuit end time Hour, minute, second
  • Short circuit starting temperature °C
  • Short circuit end temperature °C
  • Table 2 below is a table showing the short-circuit maximum current, short-circuit maximum current time, and short-circuit termination time and temperature depending on whether entropy and internal resistance change are applied in a short-circuit battery circuit with an external resistance of 30.91 m ⁇ .
  • the maximum short-circuit current was shown as 126.3A at an elapsed time of 2 minutes 5-11 seconds.
  • the short-circuit termination temperature was about 12 ° C lower than when the internal resistance was applied as the initial value. This reflects the decrease in internal resistance as the battery temperature increases.
  • the short-circuit termination temperature was about 3 ° C to 4 ° C higher than when the change of entropy was not applied.
  • Table 3 below is a table showing the short-circuit maximum current, short-circuit maximum current time, and short-circuit termination time and temperature depending on whether entropy and internal resistance changes are applied in a short-circuit cell circuit having an external resistance of 20.91 m ⁇ .
  • the maximum short-circuit current was 183A at 1 minute 45 to 51 seconds.
  • the short-circuit termination temperature was about 19 ° C lower than when the internal resistance was applied as the initial value. This reflects the decrease in internal resistance as the battery temperature increases.
  • the short-circuit termination temperature was about 4 ° C higher than when the change of entropy was not applied.
  • Table 4 below is a table showing the short-circuit maximum current, short-circuit maximum current time, and short-circuit termination time and temperature depending on whether entropy and internal resistance change are applied in a short-circuit cell circuit having an external resistance of 5.91 m ⁇ .
  • the maximum short-circuit current was 570A to 583A at an elapsed time of 52 seconds to 1 minute and 25 seconds.
  • the short-circuit termination temperature was about 90 ° C lower than when the internal resistance was applied as the initial value. This reflects the decrease in internal resistance as the battery temperature increases.
  • the short-circuit termination temperature was about 3 to 5 ° C higher than when the change of entropy was not applied.
  • Table 5 below is a table showing the short-circuit maximum current, short-circuit maximum current time, and short-circuit termination time and temperature depending on whether entropy and internal resistance changes are applied in a short-circuit cell circuit having an external resistance of 2.91 m ⁇ .
  • the maximum short-circuit current was about 1019A to 1099A at about 34 seconds to 49 seconds of elapsed time.
  • the short-circuit termination temperature was about 154 ° C to 166 ° C lower than when the internal resistance was applied as the initial value. This reflects the decrease in internal resistance as the battery temperature increases.
  • the short-circuit termination temperature was about 4 to 6 ° C higher than when the change of entropy was not applied.
  • Table 6 below is a table showing the short-circuit maximum current, short-circuit maximum current time, and short-circuit termination time and temperature depending on whether entropy and internal resistance change are applied in a short-circuit cell circuit having an external resistance of 0.91 m ⁇ .
  • the maximum short-circuit current was about 2292 A to 2615 A from about 15 seconds to 19 seconds of elapsed time.
  • the short-circuit termination temperature was about 271 ° C to 274 ° C lower than when the internal resistance was applied as the initial value. This reflects the decrease in internal resistance as the temperature of the battery increases.
  • the short-circuit termination temperature was about 4 to 8 ° C higher than when the change of the entropy was not applied.
  • FIG. 39 is a graph showing a result of calculating a voltage change for a short circuit of a battery according to various conditions. That is, FIG. 39 is a graph showing the result of calculating the change in voltage according to the external short-circuit resistance according to the state of charge (SOC) by applying Equation (17) and the characteristic values of the corresponding battery. As shown in FIG. 39, it can be seen that the lower the external resistance of the short circuit battery circuit, the lower the circuit voltage of the battery is calculated.
  • FIG. 40 is a graph showing a result of calculating a temperature change for a short circuit of a battery according to various conditions. That is, FIG. 40 is a graph showing the result of calculating the temperature change according to the external short-circuit resistance over time by applying the above-described Equation 17 and the characteristic values of the corresponding battery. As shown in FIG. 40, it can be confirmed that the short circuit discharge end time increases as the external resistance of the short circuit battery increases.
  • entropy represents an error level of about 4 ° C. to 8 ° C. in the final temperature rise calculation in the case of short-circuit discharge from 100% to 0% of the charged state.
  • the effect of entropy on the temperature rise of the battery is not very high at a current corresponding to a discharge time of 5 hours or less.
  • FIG. 41 is a graph showing a result of calculating a final temperature of a battery according to a change in external short-circuit resistance. That is, FIG. 41 is a graph showing the results calculated by differently setting the initial temperature to 18 ° C and 35 ° C and giving the battery's state of charge (SOC) differently to 100%, 80%, and 50%.
  • SOC state of charge
  • the trend that the final temperature of the battery increases as the external resistance of the short circuit decreases has the same tendency for all initial temperatures and charge states.
  • the difference in the final temperature due to the difference in the initial temperature was small, and as the temperature decreased to 80% and the charged state in 50%, the difference in the final temperature according to the difference in the initial temperature also increased. You can confirm that.
  • the difference in the final temperature depending on the state of charge is a result of the relationship of the change in internal resistance.
  • the state of charge if the state of charge is high, the internal resistance decreases due to the rapid discharge and heat dissipation of the battery, but when the state of charge is low, the difference in heat generation according to the initial temperature becomes large because the temperature of the battery is not large due to gentle discharge. Will be.
  • the difference in heat generation due to the difference in the charging state is a natural result of the difference in the amount of energy inherent in the battery, and the temperature increases differently.
  • the graph of FIG. 41 is also important in predicting the amount of heat generated depending on the state of charge.
  • the initial charging state is set to a range from 0% to 100%
  • the final charging state is set to a range from 0% to 100% in a similar manner to the method described in FIG. 41 to derive results.
  • the method similar to the method described in FIG. 41 is also useful for predicting an increase in current flow and temperature in a case where different batteries are fastened within a range of 0% to 100%. Can be used. In the case of fastening in parallel connection, current flows from a battery with a high charge state to a battery with a low charge state, and finally, all cells reach equilibrium with a charge state of the same voltage.
  • the concept of the above-described short circuit is a process of applying the battery with a constant voltage of 0V. All constant voltage processes fall into the extended analysis category of this analysis. Therefore, the charging or discharging process in which the constant current and the constant voltage are connected is also a field belonging to the extended application of this analysis.
  • the present invention described above can be embodied as computer readable codes on a medium on which a program is recorded.
  • the computer-readable medium continue to store executable computer program, or may be temporarily stored for a run or download.
  • the medium may be one which can be a variety of recording device or storage means of a single or several hardware combined form, is not limited to the medium to be directly connected to any computer system, there distributed to the network. Examples of the medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magneto-optical media such as floptical disks, And program instructions including ROM, RAM, flash memory, and the like.
  • the media can be recorded to storage media managed as an example for other media, website, etc. supplied to the app store or other retail distributor of various software applications, and servers. Accordingly, the above detailed description should not be construed as limiting in all respects, but should be considered illustrative. The scope of the invention should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
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Abstract

La présente invention concerne un procédé de prédiction des caractéristiques de court-circuit d'une batterie, le procédé consistant : à déduire des informations de caractéristiques uniques en fonction d'un état de charge (SOC) de la batterie ; en cas de court-circuit, à calculer un changement de température associé au court-circuit de la batterie à l'aide des informations de caractéristiques uniques dérivées de la batterie ; et à calculer des changements de tension et de courant associés au court-circuit de la batterie en fonction d'informations concernant le changement de température calculé.
PCT/KR2019/015100 2018-11-12 2019-11-07 Procédé de prédiction de changement de température associé à des états de batterie normale et de court-circuit Ceased WO2020101271A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR1020180138419A KR102558017B1 (ko) 2018-11-12 2018-11-12 배터리의 냉각을 통한 엔트로피 측정 방법 및 이를 이용한 배터리 온도 변화 계산 방법
KR10-2018-0138419 2018-11-12
KR1020190129659A KR102895113B1 (ko) 2019-10-18 2019-10-18 전지의 단락에 대한 전압/전류/온도 변화 계산 방법
KR10-2019-0129659 2019-10-18

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WO2020101271A1 true WO2020101271A1 (fr) 2020-05-22

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112671071A (zh) * 2021-01-07 2021-04-16 Oppo广东移动通信有限公司 充电控制方法、充电控制装置、存储介质与电子设备
CN117949829A (zh) * 2024-01-30 2024-04-30 重庆标能瑞源储能技术研究院有限公司 一种电池模型参数辨识方法、设备、介质及产品
CN118731621A (zh) * 2024-06-14 2024-10-01 西安航科创星电子科技有限公司 一种半导体器件老化测试方法、系统及介质
CN119623050A (zh) * 2024-11-25 2025-03-14 华中科技大学 液态金属电池外短路工况下的温度及热量预测方法、系统及设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000504477A (ja) * 1996-11-21 2000-04-11 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ バッテリー管理システム及びバッテリー・シミュレータ
KR20100043247A (ko) * 2007-07-26 2010-04-28 파나소닉 주식회사 전지의 내부 단락 검지 장치 및 방법, 전지 팩 및 전자 기기 시스템
JP4891315B2 (ja) * 2006-04-25 2012-03-07 日本電信電話株式会社 蓄電池の取り替え判定装置および取り替え判定方法
JP2014526781A (ja) * 2011-09-19 2014-10-06 ナンヤン テクノロジカル ユニヴァーシティー バッテリを試験するための装置およびバッテリを試験するための方法
KR20160075167A (ko) * 2014-12-19 2016-06-29 주식회사 엘지화학 이차전지의 전력 제어 장치 및 방법
KR20170059208A (ko) * 2015-11-20 2017-05-30 한국과학기술원 배터리의 동적 엔트로피 추정 방법

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000504477A (ja) * 1996-11-21 2000-04-11 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ バッテリー管理システム及びバッテリー・シミュレータ
JP4891315B2 (ja) * 2006-04-25 2012-03-07 日本電信電話株式会社 蓄電池の取り替え判定装置および取り替え判定方法
KR20100043247A (ko) * 2007-07-26 2010-04-28 파나소닉 주식회사 전지의 내부 단락 검지 장치 및 방법, 전지 팩 및 전자 기기 시스템
JP2014526781A (ja) * 2011-09-19 2014-10-06 ナンヤン テクノロジカル ユニヴァーシティー バッテリを試験するための装置およびバッテリを試験するための方法
KR20160075167A (ko) * 2014-12-19 2016-06-29 주식회사 엘지화학 이차전지의 전력 제어 장치 및 방법
KR20170059208A (ko) * 2015-11-20 2017-05-30 한국과학기술원 배터리의 동적 엔트로피 추정 방법

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112671071A (zh) * 2021-01-07 2021-04-16 Oppo广东移动通信有限公司 充电控制方法、充电控制装置、存储介质与电子设备
CN117949829A (zh) * 2024-01-30 2024-04-30 重庆标能瑞源储能技术研究院有限公司 一种电池模型参数辨识方法、设备、介质及产品
CN118731621A (zh) * 2024-06-14 2024-10-01 西安航科创星电子科技有限公司 一种半导体器件老化测试方法、系统及介质
CN119623050A (zh) * 2024-11-25 2025-03-14 华中科技大学 液态金属电池外短路工况下的温度及热量预测方法、系统及设备

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