CN109991552B - Method for estimating residual capacity of battery - Google Patents

Method for estimating residual capacity of battery Download PDF

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CN109991552B
CN109991552B CN201810901017.2A CN201810901017A CN109991552B CN 109991552 B CN109991552 B CN 109991552B CN 201810901017 A CN201810901017 A CN 201810901017A CN 109991552 B CN109991552 B CN 109991552B
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battery
value
overpotential
soc
charging
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CN109991552A (en
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方伟峰
李绮茹
高坡
董学忠
文娟·刘·麦蒂斯
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Microvast Holdings Inc
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Microvast Power Systems Huzhou Co Ltd
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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]
    • G01R31/367—Software therefor, e.g. for battery testing using modelling or look-up tables
    • 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]
    • G01R31/385—Arrangements for measuring battery or accumulator variables
    • G01R31/387—Determining ampere-hour charge capacity or SoC
    • G01R31/388—Determining ampere-hour charge capacity or SoC involving voltage measurements

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Abstract

The invention provides a method for estimating the residual capacity of a battery, which estimates the residual capacity of the battery by utilizing the corresponding relation between the concentration overpotential (or diffusion internal resistance) and the SOC of the battery. The invention utilizes the difference of concentration overpotential (or diffusion internal resistance) caused by the difference of the diffusion coefficient of the reactant or product particles of the electrode material active material particle surface layer under different SOC to establish the corresponding relation between the concentration overpotential (or diffusion internal resistance) and the SOC. In particular, the present invention can avoid estimation errors due to certain electrode materials due to the relatively flat open circuit potential over a certain SOC interval. The estimation method of the residual capacity of the battery provided by the invention has wide application range.

Description

Method for estimating residual capacity of battery
Technical Field
The present invention relates to a method of estimating a remaining capacity of a battery.
Background
Estimation of the remaining capacity of the Battery is one of the most important functions in a Battery Management System (BMS). The BMS feeds back an expectation of future usable time of the battery through an estimation of the SOC of the battery, and the battery user will decide a next operation schedule through this information. It is likely to cause much inconvenience to the user if the battery SOC estimation error is large, and even cause serious unexpected situations such as the electric vehicle being stranded due to the actual shortage of electricity at high speed, etc.
The most commonly used methods for estimating the SOC of the battery at present include an ampere-hour (integral) method and an open circuit voltage method. The ampere-hour method is to estimate the remaining capacity of a battery by accumulating the amount of electricity charged and discharged during the operation of the battery (assuming that the charge is positive and the discharge is negative) and from the initial capacity of the battery. One of the problems with this method is that as the battery running time increases, the errors in measuring and recording charge and discharge continuously accumulate, eventually leading to larger and larger errors in estimated battery SOC. In addition, the conventional ampere-hour method requires the use of, for example, an open circuit voltage method in combination with other methods.
The open circuit voltage method works on the principle that the voltage of the battery under the open circuit condition (i.e., when the passing current is zero) and the SOC have a relatively fixed corresponding relationship. During measurement, the battery needs to be kept still for a period of time (for example, several hours) in advance to enable the inside to reach balance, then the terminal voltage of the battery is recorded, and the SOC of the battery at the moment is obtained by searching the corresponding relation between the battery open-circuit voltage and the SOC at different temperatures which are measured in advance. One potential problem with the open circuit voltage method is: if the open circuit voltage of a battery does not change much within a certain SOC interval (for example, a battery made of an electrode having a phase change during charging and discharging, such as lithium titanate or lithium iron phosphate), the SOC change corresponding to a small change in the open circuit voltage may be very large, and thus the error in estimating the SOC may be very large.
Disclosure of Invention
An object of the present invention is to provide a method for estimating a remaining capacity of a battery, including:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the battery voltage from the discharging or charging cut-off moment to the time when the voltage is stable again is recorded;
detecting that the battery voltage value at the cut-off time of the discharging or charging of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3, and the battery voltage value after all the ohmic overpotential, the electrochemical overpotential and the concentration overpotential disappear is V4;
C. calculating the concentration overpotential of the battery according to the formula of V4-V3, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V4-V3I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, and continuing for the same time as that in the step B; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', the battery voltage value after the ohm overpotential, the electrochemistry overpotential and the concentration overpotential disappear is V4 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV 4 ' -V3 ' |, and calculating the actual internal resistance diffusion of the battery according to the formula Rd ' ═ V4 ' -V3 ' |/I;
F. Δ V, R at different temperatures for the battery preserved by step DdAnd SOC, and finding out the value of delta V' and delta V or R of the battery at the temperature T by using an interpolation methodd' and RdThe SOC value corresponding to the same value.
Another object of the present invention is to provide a method for estimating a remaining capacity of a battery, including:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the battery voltage from the discharging or charging cut-off moment to the time when the voltage is stable again is recorded;
detecting that the battery voltage value at the cut-off time of the discharging or charging of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3, and the battery voltage value after all the ohmic overpotential, the electrochemical overpotential and the concentration overpotential disappear is V4;
C. calculating the concentration overpotential of the battery according to the formula of V4-V3, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V4-V3I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, and continuing for the same time as that in the step B; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', the battery voltage value after the ohm overpotential, the electrochemistry overpotential and the concentration overpotential disappear is V4 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV 4 ' -V3 ' |, and calculating the actual internal resistance diffusion of the battery according to the formula Rd ' ═ V4 ' -V3 ' |/I;
G. according to the delta V, R of the battery charging at different temperatures in the step DdAnd the correspondence between SOC and Δ V, R of battery dischargedAnd the corresponding relation between the SOC and the battery state of charge, the delta V difference value delta V' of the charge and the discharge of the battery under different temperatures and the R of the charge and the discharge under different temperatures are obtaineddDifference Rd"corresponding SOC relationship;
step H. Δ V' and R for charging and discharging the battery obtained according to step Ed', calculating a difference value DeltaV' between charging and discharging of the battery and R of the charging and dischargingd"' difference value;
step I, finding out the value or R of the same delta V '″ and delta V' of the battery at the temperature T by using an interpolation methodd"' and Rd"SOC value corresponding to the same value.
Another object of the present invention is to provide a method for estimating a remaining capacity of a battery, comprising,
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stable again is recorded as V0;
detecting that the battery voltage value at the discharge or charge cut-off time of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, and the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3;
C. calculating the concentration overpotential of the battery according to the formula of V3-V0, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V3-V0I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, continuing for the same time as the step B, and recording the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stabilized again as V0'; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV ═ V3 ' -V0 ' |, and calculating the actual diffusion internal resistance of the battery according to the formula Rd ═ V3 ' -V0 ' |/I;
F. Δ V, R at different temperatures for the battery preserved by step DdAnd SOC, and finding out the value of delta V' and delta V or R of the battery at the temperature T by using an interpolation methodd' and RdThe SOC value corresponding to the same value.
Another object of the present invention is to provide a method for estimating a remaining capacity of a battery, including:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stable again is recorded as V0;
detecting that the battery voltage value at the discharge or charge cut-off time of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, and the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3;
C. calculating the concentration overpotential of the battery according to the formula of V3-V0, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V3-V0I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, continuing for the same time as the step B, and recording the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stabilized again as V0'; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV ═ V3 ' -V0 ' |, and calculating the actual diffusion internal resistance of the battery according to the formula Rd ═ V3 ' -V0 ' |/I;
G. according to the delta V, R of the battery charging at different temperatures in the step DdAnd the correspondence between SOC and Δ V, R of battery dischargedAnd the corresponding relation between the SOC and the battery state of charge, the delta V difference value delta V' of the charge and the discharge of the battery under different temperatures and the R of the charge and the discharge under different temperatures are obtaineddDifference Rd"corresponding SOC relationship;
step H. Δ V' and R for charging and discharging the battery obtained according to step Ed', calculating a difference value DeltaV' between charging and discharging of the battery and R of the charging and dischargingd"' difference value;
step I, finding out the value or R of the same delta V '″ and delta V' of the battery at the temperature T by using an interpolation methodd"' and Rd"SOC value corresponding to the same value.
Step D, obtaining the electrochemical overpotential and the charge transfer internal resistance of the battery measured at different temperatures and different SOC, and obtaining delta V, R at different temperaturesdAnd SOC, the corresponding relation comprises the corresponding relation between delta V and SOC and RdAnd the correspondence between the SOCs.
In the method for estimating the residual capacity of the battery, the SOC of the battery is controlled to reach the preset value, the capacity of the battery can be calibrated firstly, and the calibrated value of the capacity of the battery is marked as X (unit: Ah). Before the SOC of the battery is adjusted, the battery can be fully charged by a constant current and constant voltage method (namely, constant current charging is firstly utilized, when the voltage reaches the upper limit value of the battery voltage, the constant voltage and variable current charging is changed until the current is reduced to a preset value such as C/100, wherein C represents the current multiplying power based on the battery capacity, and the C/100 represents the current X/100 amperes of the battery), then the battery is discharged, and the discharge amount is controlled, so that the SOC of the battery reaches the preset value. Assuming that the preset value of the SOC of the battery is a% (a is a value between 0 and 100), the discharged amount is a.X/100.
In the method for estimating the remaining battery capacity of the present invention, the lower battery limit may be 0% or a value close to 0%, such as 5%, and the upper battery limit may be 100% or a value close to 100%, such as 95%.
The temperature of the battery is controlled to reach the preset temperature, the temperature of the test environment can be firstly adjusted to the required temperature (which can be room temperature or the allowable working temperature of other batteries), and then the battery is placed in the environment until the temperature of the battery reaches the balance, namely, the battery is consistent with the ambient temperature and does not change any more, and the error of the battery can be allowed to be within +/-2 ℃. In actual use, the preset temperature value can be arranged according to needs. Measuring with more temperature values over the operating temperature range of the battery may make the subsequent SOC estimation more accurate.
After the discharge or charge current is cut off, the voltage value of the battery after the ohm overpotential disappears is recorded as V2, namely the voltage value of the battery after the ohm overpotential disappears due to the loss of the current load after the discharge or charge is cut off. The characteristic time scale of ohmic polarization is between 1 microsecond and 1 millisecond. In practical measurement, the voltage rising or falling is a slow process due to the effect of a solid-liquid interface double electric layer in the battery, an obvious platform is arranged after the slow process is finished, and the voltage corresponding to the platform is V2. Namely, the value of V2 is the platform voltage of the first platform after the voltage rises or falls after V1. The schematic diagrams in the case of discharging and charging are shown in fig. 1 and fig. 2, respectively (the horizontal axis represents time, for reference only, and does not represent a true time scale).
It should be noted that the characteristic time magnitudes of the electrochemical polarization and the concentration polarization are much larger than those of the ohmic polarization, so the values here assume that the changes of the electrochemical polarization and the concentration polarization in the time period from V1 to V2 are negligible.
In another embodiment of the present invention, the value-taking point of V3 is determined by the following formula, i.e. the point after V2 when the ratio of the voltage value at that moment to the voltage value with respect to time is less than the preset value C1: dV/dt/| V < C1; the value-taking point of V3 'is determined by the following formula, namely, the point after V2' when the ratio of the voltage value at that moment to the voltage value of the voltage value with respect to time is less than the preset value C1: | dV '/dt' |/V '< C1'.
In another embodiment of the present invention, the value of C1 is 0.001s‐1To 0.5s‐1In between, the value of C1' is 0.001s‐1To 0.5s‐1In the meantime. More preferably, the value of C1 is 0.01s‐1To 0.2s‐1In between, the value of C1' is 0.01s‐1To 0.2s‐1In the meantime.
The cell voltage value after the ohmic overpotential and the electrochemical overpotential were detected to disappear was V3. The value point of V3 is within the characteristic time range of electrochemical polarization after V1 (characteristic time scale between 1 millisecond and 1 second). The invention determines the V3 value taking point through the following formula, namely the point when the ratio of the voltage value at the moment to the voltage value of the voltage value relative to the time is less than the preset value C1 after V2:
|dV/dt|/V<C1
the value of C1 should be noted that, in general, the value of C1 can be selected to be 0.001s‐1To 0.5s‐1In the meantime. If the value of C1 is too large, a large error exists between the final calculated electrochemical overpotential (internal resistance to charge transfer) and the true value, and if the value of C1 is too small, the influence on the acquired data caused by concentration polarization change needs to be considered. Multiple experiments prove that the value of C1 is 0.01s‐1To 0.2s‐1In the meantime, the accuracy of the calculation result can be ensured, and the influence caused by concentration polarization change can be effectively reduced.
It should be noted here that the values here assume negligible changes in concentration polarization over the time period from V2 to V3, since the characteristic time scale of concentration polarization is much greater than that of electrochemical polarization. Which causes errors within an acceptable range.
The cell voltage value after the ohmic overpotential, the electrochemical overpotential, and the concentration overpotential were all disappeared was detected to be V4, i.e., the voltage at which the cell regained equilibrium. The selection of V4 generally needs to wait for more than 1h after the discharge or charge is cut off. In the case where the OCV of the battery is relatively flat (i.e., the OCV varies less between certain SOC), in order to save the measurement time, it may be considered to calculate the voltage value V0 in the equilibrium state before discharge (or charge) instead of V4 (i.e., the approximation described above).
In one embodiment of the invention, the test temperature is from-30 ℃ to 60 ℃.
In practical application, the temperature of the working environment of the battery is generally between-30 ℃ and 60 ℃, and the temperature range is selected for measurement, so that the measured overpotential of the battery can reflect the actual working condition of most batteries, and the battery can be measured at an extreme temperature (for example, above 60 ℃).
In one embodiment of the present invention, the preset current I is selected from any one of values from 0.1C to 30C.
In another embodiment of the present invention, the time of the constant current charging or discharging is selected from any one of 0.01 second to 10 hours. More preferably, the time of the constant current charging or constant current discharging is selected from any one of 1 second to 300 seconds.
The method of the invention is characterized in that the polarization characteristic time magnitudes are different due to different reasons, and the time for each to return to the equilibrium state in the relaxation time after the charge and discharge are different. Generally, the ohmic polarization is mainly due to the polarization formed when current flows through the ohmic resistance on the electrode system, and usually disappears rapidly after the end of charge and discharge, with a characteristic time of between 1 microsecond and 1 millisecond. And the electrochemical polarization is mainly due to polarization caused by charge transport in the interface layer of the electrode active material and the electrolyte. Since this interface layer is usually thin, the time for electrochemical polarization to disappear after completion of charge and discharge is also relatively short, and the characteristic time is usually 1 millisecond to 1 second. The concentration polarization includes concentration polarization in the electrolyte and concentration polarization in the electrode active material. The characteristic time of the former is generally between 1 second and 1000 seconds, while the characteristic time of the latter is generally between 100 seconds and 10000 seconds.
The principle of the present invention for estimating the battery using the linear correspondence between the concentration overpotential (diffusion internal resistance) and the SOC is described below. There are at least two different phases during charge and discharge for active material particles in an electrode where there is a phase change during charge/discharge, and the diffusion rates of reactant (or product) particles in these two phases are generally different. Fig. 3 illustrates a phase distribution of such electrode material particles during charging and discharging and the magnitude of the diffusion coefficient of the particles in the respective phases (the situation illustrated in fig. 3 is merely illustrative of a specific example, and the method described in the present invention is equally applicable to other phase distributions and corresponding particle diffusion coefficient magnitudes).
The electrode material having at least two phases which change during charge and discharge is LixMn2O4，LixNi1/4Mn3/ 4O4，LiCo2O4，Li2Co2O4Having an AB2O4In the form of (A may be Mg, Li, Na, K; B may be Fe, Mn, Ni, Co, Cr, Cu), V2O5,MnO2(alpha,beta,gamma,delta),LiCrO2，LiMPO4(M ═ Fe, Mn, Co, Ni, or a combination thereof), Li3V2(PO4)，Li3FeV(PO4)，LiMSO4F(M＝Fe,Mn,Co,Ni)，Li2MPO4F (Fe, Mn or combinations thereof), Li2MSiO4(M ═ Fe, Mn, Co, or combinations thereof), LiMBO3(M＝Fe,Mn,Co,Ni)，LiTi2(PO4)3，LiMS2(M ═ Ti, V, Cr, Fe, Co, Ni, Cu, or a combination thereof), Li2MnO3，TiO2(rutile, beta, and anatase), Li4Ti5O12，Nb2O5，LiVS2，LiTiS2，Fe2O3,Mn2O3,Mn3O4，MoO2Graphite, Al, Sn, Si alloy, LiTi2(PS4)3And so on. The method provided by the invention is not only suitable for the electrode material with phase change, but also can be used for all electrode materials with certain corresponding relation between concentration overpotential (or diffusion internal resistance) and SOC.
In another embodiment of the invention, the battery voltage is detected using a high speed data acquisition instrument.
In another embodiment of the present invention, the step of data acquisition time of the high speed data acquisition instrument is selected from any value of 0.1 microseconds to 1 second. More preferably, the step of data acquisition time of the high-speed data acquisition instrument is selected from any value of 1 microsecond to 1 millisecond.
During the charging and discharging process of the battery, the surface layer structure of the electrode active material is changed continuously, and the conductivity is changed simultaneously, namely the conductivity is a function of SOC. At a set charge and discharge current, the different conductivities of the surface layers of the active material directly affect the magnitude of the overpotential of the electrochemical reaction. Generally, ohmic polarization, electrochemical polarization, and concentration polarization coexist and are difficult to effectively distinguish during battery charging and discharging. The method used in the invention extracts the electrochemical overpotential by the significant difference of the characteristic time of the three and according to the specific method.
During the charging and discharging process of the battery, the surface layer composition and thickness of the electrode active material are continuously changed, so that the diffusion process of reactant (or product) particles in the electrode active material is also changed simultaneously. Under the set charging and discharging current, the diffusion process directly influences the magnitude of the concentration overpotential (or diffusion internal resistance). Generally, ohmic polarization, electrochemical polarization, and concentration polarization coexist and are difficult to effectively distinguish during battery charging and discharging.
The method used in the invention extracts the overpotential of concentration polarization by the significant difference of the characteristic time of the three and according to the specific method. One advantage of the present invention that the overpotential for concentration polarization is provided is that since the diffusion coefficient of the reactant (or product) particles on the surface layer of the electrode active material particles mainly affects the overpotential (or diffusion internal resistance), the corresponding relationship between the simple overpotential (or diffusion internal resistance) and the SOC can be established to eliminate the influence caused by other measurement errors. Overpotentials such as ohmic polarization are typically affected by the contact resistance between the measurement clip and the electrode terminals.
For two-phase coexisting electrode materials, the open-circuit potential is usually kept at a constant value in the two-phase coexisting region, so that the open-circuit voltage of the battery is relatively flat in a certain SOC region. If an open circuit voltage is used, the estimation is difficult and the error may be large. The method provided by the invention ingeniously utilizes the difference of the diffusion coefficients of reactant (or product) particles on the surface layer of electrode active material particles when the electrode material is at different SOC (state of charge), and establishes the corresponding relation between the concentration overpotential (or diffusion internal resistance) and the SOC to estimate the residual capacity of the battery, thereby avoiding the problems in the prior art.
The SOC is estimated by utilizing the relation between diffusion coefficients of other physical properties of electrode materials, namely, the diffusion coefficients of reactants or product particles on the surface layer of electrode active material particles and the SOC, and the one-to-one correspondence relation between the concentration overpotential (or diffusion internal resistance) and the SOC, so that the possible problems of an open-circuit voltage method can be avoided. The battery SOC estimation method provided by the invention has a wide application range because a phase change process exists in a plurality of electrode materials or a certain corresponding relation exists between the diffusion coefficient of the product particles and the components of the surface layer or the reaction of the surface layer of the active material particles.
Drawings
FIG. 1 is a schematic diagram of a voltage, current and time curve for a battery according to one embodiment of the present invention;
FIG. 2 is a schematic diagram of voltage, current and time curves for a battery according to another embodiment of the present invention;
FIG. 3 is a graph showing the composition of the inner core layer and the surface layer of the electrode active material and the diffusion coefficient of the reactant or product particles according to an embodiment of the present invention;
FIG. 4 is a graph of battery concentration overpotential versus SOC according to one embodiment of the present invention;
FIG. 5 is a graph of battery diffusion internal resistance versus SOC in accordance with an embodiment of the present invention;
FIG. 6 is a graph of battery concentration overpotential versus SOC during discharge in accordance with another embodiment of the present invention;
fig. 7 is a graph of SOC versus battery concentration overpotential during charging in accordance with another embodiment of the present invention.
Detailed Description
Example 1
The main instrument equipment that uses in this embodiment includes the computer, a battery tester for carry out charge-discharge to the battery, and the voltage of a high-speed data acquisition appearance detection battery, other equipment are the accessory of using commonly.
In this embodiment, the measurement object is a lithium ion battery a, the positive electrode of which is a lithium iron phosphate material, the negative electrode of which is a graphite material, and the calibration capacity of which is 50Ah, and the method includes the following steps:
1. and connecting the lithium ion battery A with the measuring equipment.
2. The lithium ion battery A is placed in a thermostatic chamber, and the temperature of the lithium ion battery A is controlled to be 25 ℃.
3. The SOC of the lithium ion battery a was adjusted to 100% in accordance with the rated capacity thereof and reached equilibrium (equilibrium was considered to be reached after standing for at least 1 hour after the charge and discharge current was cut off).
4. The temperature of the lithium ion battery a was adjusted to 25 ℃, and the voltage value of the battery was recorded as V0 (i.e., the current open circuit voltage).
5. The lithium ion battery a was discharged for 10s using 4C current while voltage data was recorded using a battery tester and a high speed data acquisition instrument (time step set to 10 microseconds). Since the initial SOC of the battery is 100%, the SOC change after discharging the battery at 10s of 4C current can be calculated, i.e., (4 × 10/3600 × 100)% -1.11%. The SOC of the battery at the end of the measurement is 100% -1% — 98.89%. When the corresponding relation between the concentration overpotential (or diffusion internal resistance) and the SOC is recorded, the SOC at the end of measurement is taken as a standard. This principle applies to all the following measurement procedures and will not be repeated.
6. Steps 3 to 5 (the initial SOC of the battery test is reduced step by step in step 3) are repeated until all tests are completed, and the initial SOC of the last measurement is 10%.
The following step is the measurement of the concentration overpotential (or diffusion internal resistance) of the above-mentioned battery during charging.
7. The SOC of the lithium ion battery a was adjusted to 5% in accordance with the rated capacity thereof and reached equilibrium (equilibrium was considered to be reached after standing for at least 1 hour after the charge-discharge current was cut off).
8. The temperature of the lithium ion battery a was adjusted to 25 ℃, and the voltage value of the battery was recorded as V0 (i.e., the current open circuit voltage).
9. The lithium ion battery a was charged with 4C current for 10s while the voltage data was recorded using a battery tester and a high speed data acquisition instrument (time step set to 10 microseconds). Since the initial SOC of the battery is 5%, the SOC of the battery at the end of measurement is 5% + 1.11% — 6.11%. When the corresponding relation between the concentration overpotential (or diffusion internal resistance) and the SOC is recorded, the SOC at the end of measurement is taken as a standard.
10. And (4) repeating the steps 7 to 9 (the initial SOC of the battery test needs to be gradually increased in the step 7) until all tests are finished, wherein the initial SOC of the last measurement is 90%, and the temperature of the lithium ion battery A is adjusted to 45 ℃ in the step 4.
Fig. 1 and 2 are schematic diagrams of voltage, current and time curves of a battery measured by a lithium ion battery a using a discharging and charging method, respectively, and the horizontal axis represents time, which is used for reference only and does not represent a true time scale.
Wherein the concentration overpotential is calculated according to the formula Δ V ═ V4-V3|, and the value points of V3 and V4 are shown in fig. 1 (or fig. 2). Specifically, the value-taking point of V3 is determined by the following formula, namely, a point when the ratio of the voltage variation with respect to time to the voltage value at that time is less than the preset value C1: dV/dt/V<C1, in this example, C1 takes 0.05s‐1. The value of V4 is the battery voltage when the battery is restored to the equilibrium state, and in this embodiment, the battery voltage value is obtained after the discharge or charge current is cut off for 1 h. The internal diffusion resistance can be calculated by the formula Δ V ═ V4-V3 |/I.
Fig. 4 shows the relationship between the concentration overpotential and the measurement termination battery SOC during the discharging and charging in this embodiment. It can be seen that as the SOC changes, the concentration overpotential also changes. The principle thereof can be explained by fig. 3 (since the change in the diffusion coefficient of lithium in the negative electrode graphite material is negligible in the present embodiment with respect to the case of lithium iron phosphate of the positive electrode, it will not be discussed as a main factor hereinafter).
Due to Li+In LiFePO4The intercalation and deintercalation process of (a) is a two-phase process. Non-intercalated lithium phase, i.e. FePO4Of the order of 10‐16cm2Less than the lithium insertion phase, i.e. LiFePO4Of the order of 10‐14cm2(the physical properties of the materials prepared by different methods may vary, and the literature values are cited here as a possible mechanism for investigation). Battery in the present embodimentSince the medium lithium iron phosphate is used as the positive electrode material, the surface layer is LiFePO with a high diffusion coefficient in the lithium intercalation process shown in fig. 3(a) during the discharge process4The inner core layer is FePO with low diffusion coefficient4。
During discharge, lithium ions and electrons combine at the particle surface and diffuse inward to the interface of the two phases. As the discharge process advances, i.e., the SOC decreases, the surface layer becomes thicker, and the path of the product particles diffusing inward becomes longer, as shown in fig. 4 in which the discharge process concentration polarization increases with decreasing SOC. The charging process can be explained with the aid of FIG. 3(b), surface FePO at low SOC4The layer (low diffusion coefficient) is thin and the path of particle diffusion is short. With the progress of the charging process, the surface FePO4The layer becomes thicker, the path of particle diffusion becomes longer, resulting in a larger concentration polarization (diffusion resistance), and Li in FePO4Compared with LiFePO4The diffusion coefficient of the phases is small, and the concentration polarization of the charging process is larger than that of the discharging process as a whole, and the results in fig. 4 also corroborate this inference.
Fig. 5 illustrates the relationship between the internal resistance of diffusion during the discharging and charging processes and the measurement termination battery SOC of this embodiment, and the mechanism thereof is the same as that described above, and will not be repeated here.
When the SOC of the battery needs to be acquired, detecting the actual temperature T of the battery, performing constant-current discharging or charging on the battery by using the same preset current I in the step B, and continuing for the same time as that in the step B; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', the battery voltage value after the ohm overpotential, the electrochemistry overpotential and the concentration overpotential disappear is V4 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV 4 ' -V3 ' |, and calculating the actual internal resistance diffusion of the battery according to the formula Rd ' ═ V4 ' -V3 ' |/I;
finally, Δ V, R at different temperatures through the stored batterydAnd SOC, and finding out the value of delta V' and delta V or R of the battery at the temperature T by using an interpolation methodd' and RdThe SOC value corresponding to the same value. The specific procedure will be described in example 2.
Example 2
The apparatus and lithium ion battery a used in this example were the same as those in example 1.
First, refer to the procedure of the discharging process in example 1 (note: the test parameters in step 5 in this embodiment are set to be: charging the lithium ion battery A with 1C current for 5 s; and the temperature of the lithium ion battery A in step 2, step 4 and step 8 is controlled at 10 ℃ or 30 ℃ respectively);
the corresponding relationship between the concentration overpotential Δ V and the SOC of the lithium ion battery a at 10 ℃ and 30 ℃ respectively is obtained, and a curve of the two corresponding relationships is obtained by a curve fitting method, as shown in fig. 6. And secondly, obtaining a corresponding relation curve between the concentration overpotential delta V and the SOC at the temperature of 15 ℃ by a linear interpolation method. The three curves are shown in fig. 7, which are the corresponding relationship between the SOC and the concentration overpotential Δ V at 10 ℃ and 30 ℃ obtained by the test, and the corresponding relationship between the SOC and the concentration overpotential Δ V at 15 ℃ obtained by interpolation. The SOC is taken as the ordinate and the concentration overpotential Δ V is taken as the abscissa here for convenience of the following explanation of the verification process.
This example plans to verify the SOC estimation of cell a at 15 ℃. The specific steps are as follows,
1. and connecting the lithium ion battery A with the measuring equipment.
2. The lithium ion battery A is placed in a thermostatic chamber, and the temperature of the lithium ion battery A is controlled to be 15 ℃.
3. The SOC of the lithium ion battery a was adjusted to 80.14% in accordance with the rated capacity thereof and reached equilibrium (equilibrium was considered to be reached after standing for at least 1 hour after the charge-discharge current was cut off).
4. And adjusting the temperature of the lithium ion battery A to 15 ℃.
5. The lithium ion battery a was discharged for 5s using a 1C current, while voltage data was recorded using a battery tester and a high speed data acquisition instrument (time step set to 10 microseconds). The change in SOC after a discharge of 5s at 1C current can be calculated, i.e., (1 × 5/3600 × 100)% -0.14%. The SOC of the battery at the end of the measurement is 80%.
6. Referring to example 1, the value of the concentration overpotential Δ V' is extracted from step 5. The corresponding SOC value is found from the corresponding relationship curve of SOC and concentration overpotential Δ V' at 15 deg.C in FIG. 7, and is compared with the actual value of 80%.
In the present example, a total of 4 point verifications were performed, and the results are shown in fig. 7. The SOC corresponding to the hollow points is the actual value, namely 80%, 40%, 30% and 10%, the solid points are the corresponding points found on a 15 ℃ curve according to the concentration overpotential delta V', and the SOC values corresponding to the solid points are the estimated values obtained by the method. The difference between the actual and estimated values is also listed in fig. 7. From the error value (difference between the actual SOC and the estimated SOC) in the graph, the SOC estimation method introduced by the invention has higher accuracy.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (15)

1. A method for estimating a remaining capacity of a battery, comprising:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the battery voltage from the discharging or charging cut-off moment to the time when the voltage is stable again is recorded;
detecting that the battery voltage value at the cut-off time of the discharging or charging of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3, and the battery voltage value after all the ohmic overpotential, the electrochemical overpotential and the concentration overpotential disappear is V4;
C. root of herbaceous plantCalculating the concentration overpotential of the battery according to the formula of V4-V3, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V4-V3I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, and continuing for the same time as that in the step B; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', the battery voltage value after the ohm overpotential, the electrochemistry overpotential and the concentration overpotential disappear is V4 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV 4 ' -V3 ' |, and calculating the actual internal resistance diffusion of the battery according to the formula Rd ' ═ V4 ' -V3 ' |/I;
F. Δ V, R at different temperatures for the battery preserved by step DdAnd SOC, and finding out the value of delta V' and delta V or R of the battery at the temperature T by using an interpolation methodd' and RdThe SOC value corresponding to the same value.
2. A method for estimating a remaining capacity of a battery, comprising:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the battery voltage from the discharging or charging cut-off moment to the time when the voltage is stable again is recorded;
detecting that the battery voltage value at the cut-off time of the discharging or charging of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3, and the battery voltage value after all the ohmic overpotential, the electrochemical overpotential and the concentration overpotential disappear is V4;
C. calculating the concentration overpotential of the battery according to the formula of V4-V3, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V4-V3I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, and continuing for the same time as that in the step B; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', the battery voltage value after the ohm overpotential, the electrochemistry overpotential and the concentration overpotential disappear is V4 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV 4 ' -V3 ' |, and calculating the actual internal resistance diffusion of the battery according to the formula Rd ' ═ V4 ' -V3 ' |/I;
G. according to the delta V, R of the battery charging at different temperatures in the step DdAnd the correspondence between SOC and Δ V, R of battery dischargedAnd the corresponding relation between the SOC and the battery state of charge, the delta V difference value delta V' of the charge and the discharge of the battery under different temperatures and the R of the charge and the discharge under different temperatures are obtaineddDifference Rd"corresponding SOC relationship;
H. Δ V' and R for charging and discharging the Battery obtained according to step Ed', calculating a difference value DeltaV' between charging and discharging of the battery and R of the charging and dischargingd"' difference value;
I. interpolation is used to find the value of delta V '″ which is the same as delta V' or R of the battery at the temperature Td"' and Rd"SOC value corresponding to the same value.
3. A method for estimating a remaining capacity of a battery, comprising:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stable again is recorded as V0;
detecting that the battery voltage value at the discharge or charge cut-off time of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, and the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3;
C. calculating the concentration overpotential of the battery according to the formula of V3-V0, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V3-V0I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, continuing for the same time as the step B, and recording the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stabilized again as V0'; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV ═ V3 ' -V0 ' |, and calculating the actual diffusion internal resistance of the battery according to the formula Rd ═ V3 ' -V0 ' |/I;
F. Δ V, R at different temperatures for the battery preserved by step DdAnd SOC, and finding out the value of delta V' and delta V or R of the battery at the temperature T by using an interpolation methodd' and RdThe SOC value corresponding to the same value.
4. A method for estimating a remaining capacity of a battery, comprising:
A. providing a battery, and controlling the SOC of the battery to reach a preset value, wherein the temperature of the battery reaches a preset test temperature;
B. the method comprises the steps that a preset current I is adopted to carry out constant-current discharging or charging on a battery for a preset time, then the battery is cut off, and the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stable again is recorded as V0;
detecting that the battery voltage value at the discharge or charge cut-off time of the battery is V1, the battery voltage value after the ohmic overpotential disappears is V2, and the battery voltage value after the ohmic overpotential and the electrochemical overpotential disappear is V3;
C. calculating the concentration overpotential of the battery according to the formula of V3-V0, and calculating the concentration overpotential of the battery according to the formula of RdCalculating the diffusion internal resistance of the battery according to the absolute value of V3-V0I/I;
D. changing the preset temperature value and the preset SOC value in the step A and repeating the steps A-C to finally obtain the concentration overpotential and the diffusion internal resistance measured at different temperatures and different SOCs to obtain delta V, R at different temperaturesdAnd the correspondence between SOC;
E. detecting the actual temperature T of the battery, discharging or charging the battery at a constant current by using the same preset current I in the step B, continuing for the same time as the step B, and recording the voltage value of the battery from the discharging or charging cut-off moment to the moment when the voltage is stabilized again as V0'; detecting that the battery voltage value at the battery discharging or charging cut-off time is V1 ', the battery voltage value after the ohm overpotential disappears is V2 ', the battery voltage value after the ohm overpotential and the electrochemistry overpotential disappear is V3 ', calculating the actual concentration overpotential of the battery according to the formula DeltaV ═ V3 ' -V0 ' |, and calculating the actual diffusion internal resistance of the battery according to the formula Rd ═ V3 ' -V0 ' |/I;
G. according to the delta V, R of the battery charging at different temperatures in the step DdAnd the correspondence between SOC and Δ V, R of battery dischargedAnd the corresponding relation between the SOC and the battery state of charge, the delta V difference value delta V' of the charge and the discharge of the battery under different temperatures and the R of the charge and the discharge under different temperatures are obtaineddDifference Rd"corresponding SOC relationship;
step H. Δ V' and R for charging and discharging the battery obtained according to step Ed', calculating a difference value DeltaV' between charging and discharging of the battery and R of the charging and dischargingd"' difference value;
step I, finding out the value or R of the same delta V '″ and delta V' of the battery at the temperature T by using an interpolation methodd"' and Rd"SOC value corresponding to the same value.
5. The method according to any one of claims 1 to 4, wherein the value of V2 is the plateau voltage of the first plateau after voltage ramp-up or ramp-down after V1, and the value of V2 'is the plateau voltage of the first plateau after voltage ramp-up or ramp-down after V1'.
6. The estimation method of remaining battery capacity according to claim 5, wherein the value-taking point of V3 is determined by the following formula, namely, a point after V2 when the ratio of the voltage variation with respect to time to the voltage value at that time is less than a preset value C1: dV/dt/| V < C1; the value-taking point of V3 'is determined by the following formula, namely, the point after V2' when the ratio of the voltage value at that moment to the voltage value of the voltage value with respect to time is less than the preset value C1: | dV '/dt' |/V '< C1'.
7. The method according to claim 6, wherein the value of C1 is 0.001s-1To 0.5s-1In between, the value of C1' is 0.001s-1To 0.5s-1In the meantime.
8. The method according to claim 7, wherein the value of C1 is 0.01s-1To 0.2s-1In between, the value of C1' is 0.01s-1To 0.2s-1In the meantime.
9. The method according to any one of claims 1 to 4, wherein a battery is provided, and the SOC of the battery is between 0% and 100%.
10. The method according to any one of claims 1 to 4, wherein the predetermined current I is selected from any one of values from 0.01C to 30C.
11. The method of estimating remaining battery capacity according to any one of claims 1 to 4, wherein the time of the constant-current charging or constant-current discharging is selected from any one of values from 0.01 seconds to 10 hours.
12. The method according to claim 11, wherein the time for constant-current charging or constant-current discharging is selected from any one of 1 second to 300 seconds.
13. The method of estimating remaining battery capacity according to any one of claims 1 to 4, wherein the battery voltage is detected using a high-speed data acquisition instrument.
14. The method of claim 13, wherein the step of voltage data acquisition time is selected from any one of 0.1 μ sec to 1 sec.
15. The method of estimating remaining battery capacity according to claim 14, wherein the voltage data acquisition time step is selected from any one of 1 μ sec to 1 msec.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103389468A (en) * 2012-05-08 2013-11-13 通用汽车环球科技运作有限责任公司 Battery state-of-charge observer
CN103620432A (en) * 2012-03-16 2014-03-05 株式会社Lg化学 Battery state estimation device and method
CN103869252A (en) * 2012-12-12 2014-06-18 通用汽车环球科技运作有限责任公司 Plug-in charge capacity estimation method for lithium iron-phosphate batteries
JP2015197363A (en) * 2014-04-01 2015-11-09 プライムアースＥｖエナジー株式会社 Battery state determination method and battery state determination device
CN105659102A (en) * 2013-10-21 2016-06-08 康奈可关精株式会社 Battery parameter estimation device and parameter estimation method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100823507B1 (en) * 2006-08-29 2008-04-21 삼성에스디아이 주식회사 Battery manegement system and the operating method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103620432A (en) * 2012-03-16 2014-03-05 株式会社Lg化学 Battery state estimation device and method
CN103389468A (en) * 2012-05-08 2013-11-13 通用汽车环球科技运作有限责任公司 Battery state-of-charge observer
CN103869252A (en) * 2012-12-12 2014-06-18 通用汽车环球科技运作有限责任公司 Plug-in charge capacity estimation method for lithium iron-phosphate batteries
CN105659102A (en) * 2013-10-21 2016-06-08 康奈可关精株式会社 Battery parameter estimation device and parameter estimation method
JP2015197363A (en) * 2014-04-01 2015-11-09 プライムアースＥｖエナジー株式会社 Battery state determination method and battery state determination device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
基于充电方式的锂电池SOC校准和估计方法;陈宗海等;《控制与决策》;20140630;第29卷(第6期);第1148-1152页 *
磷酸铁锂电池SOC估算方法研究;时玮 等;《电子测量与仪器学报》;20100831;第24卷(第8期);第769-774页 *

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