WO2016126075A1 - Method for determining resistance factor of secondary battery, and apparatus and method for estimating charging power using resistance factor - Google Patents

Abstract

The method for determining a resistant factor of a secondary battery according to the present invention determines, as a resistance factor corresponding to the temperature and state of charge of a secondary battery, a primary differential value for an initial charge I-V profile calculated from a current of an intersecting point meeting a boundary line at which an end-of-charge I-V profile according to a change of the size of a charging current has been set as a charging upper limit, when the secondary battery is at a predetermined temperature and state of charge. In addition, the apparatus and method for estimating charging power according to the present invention estimates charging power corresponding to the temperature and state of charge of a secondary battery while the secondary battery is being charged using a resistance factor predetermined according to the temperature and state of charge of the secondary battery.

Description

Method for determining resistance factor of a secondary battery, apparatus and method for estimating charge output using the resistance factor

This application is a priority application for Korean Patent Application No. 10-2015-0016275, filed February 2, 2015 and Korean Patent Application No. 10-2016-0012520, filed February 1, 2016. All the contents disclosed in the specification and drawings of this application are incorporated in this application by reference.

The present invention relates to an apparatus and method for determining a resistance factor of a secondary battery and estimating charge output using the resistance factor.

Applications of high performance secondary batteries require estimation of charge power corresponding to the state of charge (SOC) of the secondary battery.

For example, in hybrid electric vehicles (HEV) and electric vehicles (EV), the vehicle controller requires continuous up-to-date information from the battery management system (BMS) regarding the charge output of the secondary battery.

In the art, the output calculation technique of the secondary battery called the HPPC (Hybrid Pulse Power Characterization) method is widely known.

The HPPC method is described in the Partnership for New Generation Vehicles (PNGV) Battery Test Manual (3rd edition, February 2001) published by the Idaho National Engineering and Environment Laboratory of the US Department of Energy.

The HPPC method only estimates the output of the secondary battery by considering the operation design limit (V _min , V _max ) with respect to the voltage of the secondary battery. Therefore, this method does not consider the design state of the state of charge (z) and the current of the secondary battery.

Here, the state of charge is a relative ratio of the remaining capacity based on the capacity when the secondary battery is fully charged. The state of charge is indicated by the parameter SOC or z. To express the state of charge as a percentage, use the parameter SOC. In addition, the parameter z is used to represent the state of charge as a number between 0-1.

The HPPC method simply models the voltage of the secondary battery by the following equation (1).

<Equation 1>

V = OCV (z) + R × I

Here, OCV (z) is an open circuit voltage (OCV) of the secondary battery corresponding to the state of charge of the secondary battery, and R is a constant representing the resistance of the secondary battery.

The open voltage can be determined experimentally from a predefined SOC-OCV lookup table. That is, by mapping the open voltage corresponding to the state of charge in the lookup table, an OCV (z) value can be obtained.

1 specifically illustrates the concept of determining the charge output of a secondary battery using the HPPC method.

As shown in FIG. 1, when the secondary battery having a charged state of z _k is charged with a constant current having a size of I _ch for a predetermined time (eg, 10 sec), the charging end voltage V _ch of the secondary battery is measured as soon as the charge is completed. do. Here, the charging end voltage may vary depending on the size of the charging current and the charging time.

Then, the R _ch value corresponding to the slope of the IV profile is determined from Equation 1, and the first order V = OCV (z _k ) + R _ch * I for the IV profile is determined using the determined R _ch value. . Then, extrapolation is applied to the determined equation to determine the current value when the upper limit voltage V _limit is reached. The current thus determined is the maximum charging current I _{max, ch} .

In the HPPC method, when the maximum charging current I _{max, ch} is determined, the charging output P ^c is determined by the following equation (2).

<Equation 2>

P ^c = V _limit × I _{max, ch} = V _limit × [(V _limit -OCV (z _k )) ÷ R _ch ]

However, the HPPC method does not set an operating design limit for charging current. If the maximum charging current I _{max, ch} of the secondary battery determined by the HPPC method is larger than the upper limit charging current that the secondary battery can actually output, the charging output is determined to be larger than the performance of the secondary battery. In this case, the secondary battery may be charged under excessive conditions. In particular, in the case of lithium secondary batteries, overcharging provides a cause for the explosion of the battery.

Therefore, there is a need in the art for a new charge output estimation technique that can overcome the above-mentioned problems with the HPPC method.

SUMMARY OF THE INVENTION The present invention has been made under the background of the prior art, and an object thereof is to provide a method for experimentally determining a resistance factor of a secondary battery that can be used in a new charging output estimation method and configuring a resistance factor lookup table. .

Another object of the present invention is to provide an apparatus and method for estimating the charging output of a secondary battery with a safety margin within a charging upper limit condition using the resistance factor lookup table.

In accordance with an aspect of the present invention, a method of determining a resistance factor of a secondary battery includes: (a) a plurality of charging initial voltage data and a plurality of charging end voltages according to a change in magnitude of a charging current according to a temperature and a charging state of a secondary battery; Measuring data and storing the data in a memory; (b) determining a charging end I-V profile from the plurality of charging end voltage data and determining an intersection point at which the charging end I-V profile meets a boundary corresponding to a charging upper limit current or a charging upper limit voltage preset as a charging upper limit condition; (c) determining a charging initial I-V profile from the plurality of charging initial voltage data and determining a first derivative value for the charging initial I-V profile calculated based on the current value of the intersection; And (d) determining the determined primary differential value as a resistance factor corresponding to the temperature and state of charge of the secondary battery.

Preferably, the method for determining a resistance factor according to the present invention comprises the steps of: defining a resistance factor lookup table in the memory to map the resistance factor of the secondary battery by the temperature and state of charge of the secondary battery; And storing the determined resistance factor in the defined resistance factor lookup table.

According to one aspect, the charging initial voltage data is the voltage data measured within 1 second after the charging current is applied to the secondary battery, the charging end voltage data is when the application of the charging current to the secondary battery is finished It may be measured voltage data.

According to another aspect, the step (a), the step of maintaining a constant temperature of the secondary battery; Conducting a charging test for applying a plurality of charging currents having different sizes to the secondary battery for each state of charge of the secondary battery; And measuring and storing a charge initial voltage and a charge end voltage of the secondary battery each time a respective charging current is applied.

Preferably, the charging test may be stopped when the magnitude of the charging current applied to the secondary battery is greater than the charging upper limit current or the charging end voltage of the secondary battery measured most recently is greater than the charging upper limit voltage.

According to another aspect of the present invention, there is provided a charge output estimating apparatus for a secondary battery, including: a storage unit in which a resistance factor lookup table capable of referring to a predetermined resistance factor for each temperature and charge state of a secondary battery is stored in advance; A sensor unit measuring a charging current and a temperature of the secondary battery when the secondary battery is being charged; And determining a state of charge of the secondary battery, determining a resistance factor corresponding to the determined state of charge and the measured temperature with reference to the resistance factor lookup table, and determining the secondary battery from the determined resistance factor and the measured charging current. And a control unit for estimating the charging output.

Preferably, the resistance factor is the initial charge IV calculated from the current value of the intersection point where the charge end IV profile according to the change of the magnitude of the charge current meets the boundary set as the charge upper limit when the secondary battery has a predetermined temperature and state of charge It can be the first derivative value for the profile.

Preferably, the boundary line may be a boundary line indicating the charge upper limit current and the charge upper limit voltage.

According to one aspect, the charging initial IV profile, when a plurality of different charging current is applied to the secondary battery, the correlation between the charging current applied to the secondary battery and the voltage measured immediately after the corresponding charging current is applied It may be a graph to define.

Preferably, the plurality of voltage data constituting the initial charging I-V profile may be voltage data measured within 1 second after each charging current is applied to the secondary battery.

According to another aspect, the charging end IV profile is a correlation between the charging current applied to the secondary battery and the voltage measured when the application of the charging current is terminated when a plurality of different charging currents are applied to the secondary battery. It may be a graph defining a relationship.

Advantageously, said control unit may be configured to store said estimated charging output in said storage unit.

Optionally, the control unit can be connected with a display unit and can display the estimated charging output via the display unit.

Optionally, the control unit can be connected with a communication interface and can transmit the estimated charging output to the outside via the communication interface.

According to another aspect of the present invention, there is provided a method of estimating a charge output of a secondary battery, the method including: providing a resistance factor lookup table capable of referring to a predetermined resistance factor for each temperature and state of charge of a secondary battery; Measuring a charging current and a temperature of the secondary battery when the secondary battery is being charged; Determining a state of charge of the secondary battery; Determining a resistance factor corresponding to the determined state of charge and the measured temperature with reference to the resistance factor lookup table; And estimating the charging output of the secondary battery from the determined resistance factor and the measured charging current.

Preferably, the resistance factor is the initial charge IV calculated from the current value of the intersection point where the charge end IV profile according to the change of the magnitude of the charge current meets the boundary set as the charge upper limit when the secondary battery has a predetermined temperature and state of charge It can be the first derivative value for the profile.

The method of estimating the charge output of the secondary battery according to the present invention may further include storing, displaying or transmitting the estimated charge output.

According to one aspect of the invention, it is possible to easily determine the resistance factor used to estimate the charging output of the secondary battery within the safety margin.

According to another aspect of the present invention, the charging output of the secondary battery can be reliably estimated with a safety margin from the charging upper limit condition of the secondary battery.

According to another aspect of the present invention, it is possible to prevent the voltage or the charging current of the secondary battery from excessively increasing during the charge control process of the secondary battery.

The following drawings appended hereto illustrate one embodiment of the present invention, and together with the following description serve to further understand the spirit of the present invention, the present invention is limited only to those described in such drawings. It should not be interpreted.

1 illustrates an I-V profile for explaining a problem when an upper limit for the charging current is not set when determining the charging output of a secondary battery using the HPPC method.

2 is a schematic diagram of a resistance factor determination system according to an exemplary embodiment of the present invention.

3 is a flowchart illustrating a flow of a resistance factor determination method using the resistance factor determination system of FIG. 2.

4 is a flowchart illustrating an operation S140 in detail in the flowchart of FIG. 3.

5 is a charge test by the charge test algorithm of FIG. 4 when the state of charge of a lithium secondary battery including lithium metal oxide (LiNi _x Mn _y Co _z O ₂ ) and graphite (graphite) in a positive electrode and a negative electrode is 20% Graphs showing the results of plotting the initial charging IV profile and the end charging IV profile by using the charging initial voltage data and the charging end voltage data obtained by the following.

FIG. 6 illustrates a charging initial IV profile and an end charging IV using charging initial voltage data and charging end voltage data obtained by performing a charging test by the charging test algorithm of FIG. 4 when the state of charge of the lithium secondary battery is 70%. These graphs show the results of plotting profiles.

FIG. 7 illustrates a maximum charge current I _{max, ch} obtained by using an intersection point where a charge end IV profile corresponding to each charge state meets an upper charge limit condition when the state of charge of the lithium secondary battery changes from 0% to 100%. This is a graph plotting the change pattern of).

8 is a schematic configuration diagram of an apparatus for estimating charge output of a secondary battery according to an exemplary embodiment of the present disclosure.

9 is a flowchart illustrating a method of estimating a charge output of a secondary battery according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own applications. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one embodiment of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them in the present invention point of view. It should be understood that there may be variations and examples.

In the embodiments described below, the secondary battery refers to a lithium secondary battery. Here, the lithium secondary battery is a generic term for a secondary battery in which lithium ions act as operating ions during charging and discharging to induce an electrochemical reaction in the positive electrode and the negative electrode.

On the other hand, even if the name of the secondary battery is changed depending on the type of electrolyte or separator used in the lithium secondary battery, the type of packaging material used to package the secondary battery, the internal or external structure of the lithium secondary battery, the lithium ion is used as the working ion. All secondary batteries should be interpreted as being included in the category of the lithium secondary battery.

The present invention is also applicable to secondary batteries other than the lithium secondary battery. Therefore, even if the operating ion is not a lithium ion, any secondary battery to which the technical idea of the present invention can be applied should be construed as being included in the scope of the present invention regardless of its type.

In addition, a secondary battery is not limited by the number of elements which comprise it. Thus, a secondary battery may include a single cell including an assembly of an anode / membrane / cathode and an electrolyte in one package, an assembly of a single cell, a plurality of assemblies connected in series and / or in parallel, and a plurality of modules in series and / or It is to be understood that packs connected in parallel, battery systems in which multiple packs are connected in series and / or in parallel, and the like.

Embodiments described first below relate to a method of determining a resistance factor used to estimate a charge output of a secondary battery.

In order to determine the resistance factor used when estimating the charge output of the secondary battery, a resistance factor determination system 10 as shown in FIG. 2 may be provided.

In the resistance factor determination system 10 according to an embodiment of the present invention, the secondary battery B is charged or discharged to charge the secondary battery B at a predetermined charging current for a predetermined time or adjust the state of charge of the secondary battery B to a desired value. Device 20.

Preferably, the charging and discharging device 20 charges or discharges the secondary battery B for a predetermined time with a constant current having various sizes.

The charging and discharging device 20 includes a charging unit capable of charging the secondary battery B, and a discharge unit capable of discharging the secondary battery B. FIG.

The charging unit may comprise a charging circuit known in the art, and similarly the discharge unit may comprise a discharge circuit known in the art.

The resistance factor determination system 10 further includes a charging initial voltage and a set charging time immediately after the secondary battery B starts to be charged while the secondary battery B is being charged by the charging / discharging device 20 for a predetermined time. And a voltage measuring device 30 capable of measuring the charge termination voltage when it is finished.

In one example, when the secondary battery B is charged for 10 seconds, the initial charge voltage is a voltage measured within 1 second after the start of the charging current, for example, 0.1 second and the end charging voltage is the charge current. Refers to the voltage measured after the start of flow, for example after 10 seconds have elapsed.

The initial charging voltage and the end charging voltage mean the voltage measured at the beginning of the charge and the second half of the charge, and thus the timing at which the initial charge voltage and the end charge voltage are measured is not limited to the above, and can be changed as many as possible. .

Preferably, the voltage measuring device 30 may include a volt meter or voltage measuring circuit known in the art.

The resistance factor determination system 10 further includes a current measuring device 35 capable of measuring the current of the secondary battery B while the secondary battery B is charged or discharged by the charging / discharging device 20 for a predetermined time. More).

In one example, the current measuring device 35 measures the current of the secondary battery (B) at time intervals while the secondary battery (B) is being charged or discharged, the computing device 40 which will be described later the measured current value Can be provided as

Preferably, the current measuring device 35 may include a current meter or a current measuring circuit known in the art.

Preferably, the resistance factor determination system 10 further includes a computing device 40. The computing device 40 is connected to the charging and discharging device 20, the voltage measuring device 30, and the current measuring device 35, and controls each device according to an embodiment of the present invention. .

The computing device 40 may set a plurality of charging current magnitudes, a charging time, and the like, to be applied when the secondary battery B is charged at the request of the system operator. To this end, the computer device 40 may provide the system operator with a graphical user interface for inputting various setting values.

The computing device 40 may also receive a charging initial voltage and a charging end voltage from the voltage measuring device 30 while the secondary battery B is being charged.

The computing device 40 may also receive the current measurement value of the secondary battery B from the current measurement device 35 at intervals while the secondary battery B is being charged or discharged.

Preferably, the computing device 40 includes a resistance factor determination program 60 capable of determining the resistance factor of the secondary battery B in an automated manner, and a program including control logic of the resistance factor determination program 60. The memory 50 may store data generated in a process of executing code and the control logic and predefined data referenced in estimating a resistance factor.

Preferably, the computing device 40 may include a microprocessor that executes predefined control logics of the resistance factor determination program 60.

In the following description, it is noted in advance that the function performed by the resistance factor determination program 60 is performed by a microprocessor from a hardware point of view.

FIG. 3 is a flowchart sequentially illustrating a method of determining a resistance factor used for estimating charge output of a secondary battery B using the resistance factor determination system 10 illustrated in FIG. 2.

Referring to FIG. 3, first, a secondary battery B for determining a resistance factor is mounted in the resistance factor determination system 10 by a system operator (S100), and the resistance factor determination program 60 is calculated by the computing device 40. ) Is driven (S110).

Here, the secondary battery B is preferably a battery in a BOL (Beginning Of Life) state.

When the resistance factor determination program 60 completes driving, the resistance factor determination program 60 visually outputs a charging condition setting interface having a graphical user interface (GUI) for inputting charging conditions to a system operator through a monitor of the computing device 40. (S110).

For example, the system operator may use the charging condition setting interface to apply to the secondary battery a charge state interval (0 to 100%) and a charge state interval (5%) to perform a charge test. A plurality of charge current magnitudes (50A, 100A, 150A, 200A, 225A, 275A, etc.), time (10sec) when the charge current is applied to the secondary battery (B), timing information at which the charge initial voltage and the charge end voltage are measured (0.1 sec and 10 sec) and the like can be set.

Subsequently, the resistance factor determination program 60 receives charging setting information from the system operator through the charging condition setting interface and stores the charging setting information in the memory 50 (S120).

Subsequently, the resistance factor determination program 60 may include a charge upper limit setting interface including a GUI for inputting a charge upper limit condition including a charge upper limit current (I _{limit, ch} ) and a charge upper limit voltage (V _{limit, ch} ). Displayed on the monitor of the computing device 40 and receives the charge upper limit condition from the system operator and stored in the memory 50 (S130)

For example, the system operator, by using the charging upper limit setting interface, and set the upper limit charge current (I _{limit, ch)} as 240A, may set the charging upper limit voltage (V _{limit, ch)} to 4.16V.

Subsequently, the resistance factor determination program 60 controls the charging / discharging device 20 and the voltage measuring device 30 with reference to the charge setting information stored in the memory 50 to thereby differ from each other according to the state of charge of the secondary battery B. As a charging response characteristic for a plurality of charging currents having a magnitude, the charging initial voltage and the charging end voltage are measured, and the measured charging initial voltage and the charging end voltage are received from the voltage measuring device 30 and stored in the memory 50. (S140).

4 is a flowchart illustrating a process of measuring a charging initial voltage and a charging end voltage in a plurality of charging current conditions for each state of charge of a secondary battery according to an exemplary embodiment of the present invention.

In FIG. 4, I _ch represents the charging current applied to the secondary battery B, and V _i and V _f represent the charging initial voltage and the charging end voltage measured while the secondary battery B is being charged, respectively.

Referring to FIG. 4, first, the resistance factor determination program 60 controls the voltage measuring device 30 and the temperature adjusting device 70 to measure the open voltage and the temperature of the secondary battery B (S141). The charging state corresponding to the measured opening voltage and temperature is determined by referring to the OCV-SOC lookup table stored in advance in step 50 (S142).

For reference, the OCV-SOC lookup table includes charge state information corresponding to an open voltage and a temperature of the secondary battery B.

Next, the resistance factor determination program 60 determines whether the state of charge determined in step S142 is an initial value (S143). For example, the initial value may be 0%.

If the state of charge is not the initial value, the resistance factor determination program 60 may determine the discharge condition including the magnitude of the discharge current and the discharge time required to adjust the state of charge of the secondary battery B to the initial value. Determining by using, and controlling the charging and discharging device 20 to discharge the secondary battery (B) according to the determined discharge conditions to adjust the state of charge of the secondary battery (B) to the initial value (S144) and the process to step S145 To fulfill.

Here, when the capacity of the secondary battery B to be discharged in order to adjust the state of charge of the secondary battery B to an initial value is Q (Ah), after determining the magnitude of the discharge current as the primary, the Q value is the magnitude of the current. Divide by value to determine discharge time. The magnitude of the discharge current may be preset.

On the other hand, if the state of charge of the secondary battery (B) corresponds to the initial value, the resistance factor determination program 60 immediately proceeds to step S145.

Subsequently, the resistance factor determination program 60 controls the charging / discharging device 20 to apply the charging current I _ch having the smallest size among the preset charging currents to the secondary battery B for a preset time. The secondary battery B is charged (S145).

In addition, the resistance factor determination program 60 controls the voltage measuring device 30 while the secondary battery B is being charged to measure the charging initial voltage _Vi and the charging end voltage V _f at a preset timing. Then, the charging initial voltage V _i and the charging end voltage V _f measured from the voltage measuring device 30 are received and stored in the memory 50 (S146).

As a specific example, when the secondary battery B is charged for 10 seconds, the resistance factor determination program 60 may charge initial voltage V _i and end of charge voltage of the secondary battery B at the timing of 0.1 second and 10 seconds. The voltage measuring device 30 can be controlled so that V _f can be measured.

Subsequently, the resistance factor determination program 60 determines that the magnitude of the charging current I _ch applied as the charging condition of the secondary battery B or the charging end voltage V _f measured in step S146 are out of the preset charging upper limit condition. It is determined whether or not (S147).

Here, when the magnitude of the charging current (I _ch ) is larger than the set charging upper limit current (I _{limit, ch} ) or the magnitude of the measured charging end voltage (V _f ) is larger than the charging upper limit voltage (V _{limit, ch} ), the charging current The magnitude of (I _ch ) or the charge termination voltage (V _f ) are outside the charge upper limit conditions.

If it is determined as NO in step S147, the resistance factor determination program 60 controls the charging / discharging device 20 to discharge the secondary battery B so that the secondary battery B is in a state before the charging current is applied. The state of charge is returned (S148).

In this case, the magnitude and the discharge time of the discharge current may be adjusted to be substantially the same as the magnitude and the charge time of the charge current applied when the secondary battery B is charged.

Subsequently, the resistance factor determination program 60 increases the size of the charge current I _{ch to} be applied to the secondary battery B to the next larger size than before by referring to the charge setting information stored in the memory 50. In operation S149, the charging / discharging device 20 is controlled to charge the secondary battery B with a larger charging current I _ch than before (S150), and the voltage measuring device 30 is controlled while charging is performed. The initial voltage V _i and the charge termination voltage V _f are measured and stored in the memory 60 (S151).

Here, the timing at which the measured charge initial voltages (V _i) and the charging end voltage (V _f) is substantially the same timing to be applied in step S146 and.

When the step S151 is finished, the resistance factor determination program 60 proceeds to step S147.

Thus, the resistance factor determining program 60, the charging current (I _ch) is applied to the secondary battery (B) increasing in accordance with the terms of the size pre-set in the charging current (I _ch) secondary battery (B) to be applied to the Steps S148 to S151 are repeated until the magnitude of the charge termination voltage V _f measured as a magnitude or a charge response characteristic deviates from the charge upper limit condition.

On the other hand, if it is determined as YES in step S147, the resistance factor determination program 60 ends the charging test when the state of charge of the secondary battery B is the initial value, and the process proceeds to step S152.

In step S152, the resistance factor determination program 60 is set to the upper limit value of the current state of charge before setting the charge test in a state in which the state of charge of the secondary battery B on which the charge test is performed is increased by a predetermined width. Is 100% or more.

If it is determined as YES in step S152, the resistance factor determination program 60 completes the charging test for the secondary battery (B) and proceeds to step S160 of FIG.

On the other hand, if NO in step S152, the resistance factor determination program 60 increases the state of charge of the secondary battery B by a predetermined width ΔSOC with reference to the charge setting information stored in the memory 50 (S153). By controlling the charge / discharge device 20 to charge the secondary battery B, the state of charge of the secondary battery B is adjusted to the state of charge determined in step S153 (S154). The magnitude and the charging time of the charging current applied to the secondary battery B in step S154 may be determined by the ampere counting method using the SOC value determined in step S153.

Herein, when the capacity of the secondary battery B to be charged is Q '(Ah) in order to adjust the state of charge of the secondary battery B to the SOC value determined in step S153, the size of the charging current is determined to be primary and Q is determined. The charge time can be determined by dividing the value by the magnitude of the current. The magnitude of the charging current may be set in advance.

Subsequently, the resistance factor determination program 60 transfers the process to step S145, whereby the magnitude of the charge current I _ch or the charge end voltage V _f with respect to the state of charge of the secondary battery B adjusted in step S153. The charging initial voltage (V _i ) and the charging end voltage (V _f ) are increased while increasing the magnitude of the charging current (I _ch ) applied to the secondary battery (B) according to the preset condition until the deviation from the preset charging upper limit condition. The above process of measuring and storing the data in the memory 50 is repeated again.

The resistance factor determination program 60 may repeat steps S145 to S151 until the state of charge of the secondary battery B becomes 100%, and when the state of charge of the secondary battery B reaches 100% or more, The charging test performed for each state of charge of the battery B is completed, and the process proceeds to step S160 of FIG. 3.

Hereinafter, for convenience of description, when the state of charge of the secondary battery B is SOC _p and the magnitude of the charging current is I _{ch (k)} , which is the k th size among m preset sizes, the memory 50 is measured. The charging initial voltage (V _i ) and the charging end voltage (V _f ) stored in each of the following will be displayed as follows.

Initial Charging Voltage: V _{i, @ SOCp} (I _{ch (k)} ) [k = 1,... , m]

Charge end voltage: V _{f , @ SOCp} (I _{ch (k)} ) [k = 1,… , m]

In addition, when the magnitude of the charge current I _ch applied to the secondary battery B and the voltage of the secondary battery B are defined as X coordinates and Y coordinates, respectively, the initial charge data and the charge end voltage data may be defined as follows. It can be defined as the coordinate data of.

Initial Charging Data: (I _{ch (k)} , V _{i, @ SOCp} (I _{ch (k)} )) [k = 1,... , m]

Charging end data: (I _{ch (k)} , V _{f , @ SOCp} (I _{ch (k)} )) [k = 1,... , m]

The I-V profile plotted by the plurality of charging initial voltage data and the plurality of charging end voltage data may be defined as a charging initial I-V profile and a charging end I-V profile, respectively.

FIG. 5 illustrates a lithium secondary battery including lithium metal oxide (LiNi _x Mn _y Co _z O ₂ ) and graphite in a positive electrode and a negative electrode and having a capacity of 26 Ah using the charging test algorithm of FIG. 4. These graphs show the results of plotting the charging initial IV profile and the charging termination IV profile by measuring the initial charging voltage (V _i ) and the charging termination voltage (V _f ) while increasing the magnitude of the current.

In the experiment for obtaining the graph of FIG. 5, the state of charge of the lithium secondary battery was equally adjusted to 20% before the charging current was applied to the lithium secondary battery.

On the IV profile illustrated in FIG. 5, the X coordinate of the marked position is the magnitude of the charging current I _ch applied to the secondary battery B, and the Y coordinate is the value when the corresponding charging current I _ch is applied. The charging initial voltage V- _i or the charging end voltage V _f is indicated.

In FIG. 5, the dotted line indicates the charge upper limit condition, the vertical dotted line indicates the charge upper limit current (I _{limit, ch} ), and the horizontal dotted line indicates the charge upper limit voltage (V _{limit, ch} ).

As shown, the charge initial IV profile and the charge end IV profile have the same Y intercept. For reference, the Y segment corresponds to the open voltage measured when the charging current I _ch is not applied to the secondary battery B. The open circuit voltage is uniquely determined according to the state of charge of the secondary battery B. FIG.

Since the charging initial IV profile (dotted line) is a plot of the voltage measured according to the magnitude of the charging current I _ch immediately after the charging current I _ch is applied to the secondary battery B, for example, 0.1 second or later, Located below the ending IV profile.

When applied to the charging current (I _ch) The secondary battery (B), because the voltage is a charging current (I _ch) flow is gradually increased until it stops, so the more late the time of measuring the voltage measurement of the voltage is high.

On the other hand, the magnitude of the current at the intersection where the end of charge IV profile (solid line) meets the charge upper limit condition corresponds to the maximum charging current (I _{max, ch} ) that can be applied to the secondary battery (B), and this current value is the secondary battery ( It can be uniquely determined according to the state of charge of B).

Referring to FIG. 5, it can be seen that the maximum charging current (I _{max, ch} ) that can be applied to the lithium secondary battery having a 20% state of charge is equal to the upper _limit charging current I _{limit, ch} set as the boundary condition.

FIG. 6 illustrates an initial charging IV profile and an end of charging using the initial charging voltage data and the end charging voltage data obtained by performing the charging test by the algorithm illustrated in FIG. 4 when the state of charge of the lithium secondary battery described above is 70%. These graphs show the results of plotting the IV profile.

In Fig. 6, the maximum charge current I _{max, ch} that can be applied to the secondary battery B whose charge end IV profile (solid line) meets the charge upper limit condition, i.e., the state of charge is 70%. Is smaller than the charge upper limit current (I _{limit, ch} ) set as the charge upper limit condition. End point of charge IV intersection point (solid line) meets the upper charge limit condition V = V _{limit, ch} This is because it is on a straight line.

FIG. 7 illustrates the maximum charge current I _max obtained by using an intersection point where the charge end IV profile corresponding to each charge state meets the charge upper limit condition when the state of charge of the lithium secondary battery is changed from 0% to 100%. A plot of the change pattern of _ch ).

As shown, the maximum charging current (I _{max, ch} ) that can be applied to the secondary battery (B) is constant in a low state of charge of the lithium secondary battery, but when the state of charge increases to 40% or more, the secondary battery (B). It can be seen that the maximum charging current (I _{max, ch} ) that can be applied to) gradually decreases.

The reason why the graph as shown in FIG. 7 is obtained is that in the charging state section in which the maximum charging current I _{max, ch} is constant, the charging end IV profile intersects the line of I = I _{limit, ch} corresponding to the vertical line of the upper limit of charging condition, and the maximum This is because the charging end IV profile intersects the V = V _{limit, ch} straight line corresponding to the horizontal line of the upper charging limit condition in the charging state section in which the charging current I _{max, ch} gradually decreases.

3 again, the resistance factor determination program 60 according to the present invention uses the charging initial voltage data and the charging end voltage data stored in the memory 50 for each state of charge of the secondary battery B. The resistance factor R _{ch @ SOC} can be determined for each state of charge.

In addition, the resistance factor determination program 60 stores the resistance factor information for each charging state in the form of a lookup table in the form of a lookup table so that the resistance factor R _{ch @ SOC} can be mapped by the charging state of the secondary battery B. Can be stored. Hereinafter, the lookup table is defined as a resistance factor lookup table.

Specifically, the resistance factor determination program 60 determines the charging end I-V profile (solid line graphs of FIGS. 5 and 6) from the charging end voltage data stored in the memory 50 for each charging state (S160).

Subsequently, the resistance factor determination program 60 calculates an X coordinate at a point where each end-of-charge IV profile determined in step S160 intersects with a charge upper limit condition (a horizontal dotted line or a vertical dotted line in FIGS. 5 and 6). The maximum charging current I _{max, ch} of the secondary battery B is determined for each charging state of (B) (S170).

Subsequently, the resistance factor determination program 60 determines a charging initial IV profile (dashed line graphs of FIGS. 5 and 6) corresponding to each charging state from the charging initial voltage data stored in the memory 50 for each charging state (see FIG. 5 and FIG. 6). S180).

Subsequently, the resistance factor determination program 60 determines, for each state of charge _, the first derivative value dV / dI of the initial charge IV profile determined in step S180 based on the maximum charging current I _{max, ch} determined in step S170. _{@ Imax, ch} may be calculated and the calculated value may be determined as the resistance factor R _{ch @ SOC} of the secondary battery B (S190).

In the graph illustrated in FIG. 5, the resistance factor R _{ch @ 20 %} when the state of charge of the lithium secondary battery is 20% is the first derivative value for the dotted line profile calculated when the charge current corresponds to l _{limit, ch} . dV / dI).

Similarly, in the graph illustrated in FIG. 6, the resistance factor R _{ch @ 70 %} when the state of charge of the lithium secondary battery is 70% is the primary for the dotted line profile calculated when the charge current corresponds to l _{max, ch} . Corresponds to the derivative value (dV / dI).

Subsequently, the resistance factor determination program 60 may store the resistance factor R _{ch @ soc} determined for each state of charge of the secondary battery B in the resistance factor lookup table defined in the memory 50 (S200).

Preferably, the resistance factor lookup table has a data structure capable of mapping the resistance factor R _{ch @ soc} of the secondary battery B by the state of charge of the secondary battery B.

On the other hand, the resistance factor determination system 10 according to the present invention is a temperature control device 70 for maintaining a constant temperature of the secondary battery (B) during the charging test for each state of charge of the secondary battery as shown in FIG. ) May be further included.

In this case, the resistance factor determination program 60 controls the temperature controller 70 when the charge test is performed according to the algorithm shown in FIG. 4 to set the temperature of the secondary battery B to a value set by the system operator. You can keep it constant.

Preferably, the temperature control device 70 is connected to the computing device 30, the air-cooled cooling fan to lower the temperature of the secondary battery (B) and the heater to increase the temperature of the secondary battery (B) and the secondary battery ( A temperature sensor for measuring the temperature of B) and a temperature setting value are provided from the resistance factor determination program 60. The temperature of the secondary battery B is measured using the temperature sensor, and the cooling fan or the heater is controlled. It may include a controller for controlling the temperature of the secondary battery (B) to the temperature set value. In addition, the temperature control device 70 measures the temperature of the secondary battery B at the request of the resistance factor determination program 60 using a temperature sensor and provides the measured temperature value to the computing device 30. can do.

In addition, the resistance factor determination program 60 may repeatedly perform the steps disclosed in FIG. 4 with respect to a plurality of temperature conditions, and the resistance factor R _{ch @ SOC} of the secondary battery corresponding to each state of _{charge is} also determined by the secondary battery ( Can be determined according to the temperature of B).

Specifically, the resistance factor determination program 60 uses the temperature controller 70 to maintain the temperature of the secondary battery B constant under the condition set by the system operator, while charging initial voltage data for each state of charge of the secondary battery. And the charging end voltage data may be measured and stored in the memory 50. The process may be repeated for a plurality of temperature conditions set by the system operator, and the initial charging voltage data and the charging initial voltage data may be charged according to the state of charge of the secondary battery. The termination voltage data may be measured and stored in the memory 50.

In addition, the resistance factor determination program 60 may determine the resistance factor R _{ch @ SOC} corresponding to the state of charge of the secondary battery B by temperature using the charging initial voltage data and the charging end voltage data stored in the memory 50. Can be.

In addition, the resistance factor determination program 60 defines a resistance factor lookup table for each temperature in the memory 50, and the resistance factor R _{ch @ SOC} for each charging state determined according to the temperature conditions is added to the resistance factor lookup table defined for each temperature. Can be stored.

The plurality of temperature values for which the resistance factor R _{ch @ SOC} is to be determined may be preset by the system operator. To this end, the charging condition setting interface provided by the resistance factor determination program 60 may further include a GUI that allows a system operator to set a plurality of temperature values. In addition, the resistance factor determination program 60 may store a plurality of temperature values set by the system operator in the memory 50.

The resistance factor R _{ch @ SOC} of the secondary battery B described so far can be used to estimate the charging output of the secondary battery B in real time.

8 is a block diagram schematically illustrating a configuration of an apparatus 100 for estimating charge output of a secondary battery according to an exemplary embodiment of the present disclosure.

Referring to FIG. 8, the charging output estimating apparatus 100 includes a sensor unit 110 and a control unit 120, and is electrically connected to the secondary battery B while the secondary battery B is being charged. The charge output of the secondary battery B can be estimated.

The secondary battery B is electrically connected to the charger 130. The charger 130 is included in a device on which the secondary battery B is mounted. For example, the charger 130 may be a charging unit included in an electric vehicle or a hybrid vehicle.

Preferably, the charging unit may supply the regeneration charging current generated when the electric vehicle or the hybrid vehicle is decelerated to the secondary battery B under the control of the charger controller 180 described later.

Preferably, the charging output estimating apparatus 100 may include a storage unit 140. The storage unit 140 is not particularly limited as long as it is a storage medium capable of recording and erasing information.

As an example, the storage unit 140 may be a RAM, a ROM, or a register, but is not limited thereto.

Preferably, the storage unit 140 may be connected to the control unit 120 via, for example, a data bus so as to be accessible by the control unit 120.

The storage unit 140 also stores and / or updates and / or erases and / or programs containing various control logics performed by the control unit 120 and / or data generated when the control logic is executed. send.

The storage unit 140 may be logically divided into two or more, and is not limited to being included in the control unit 120.

Preferably, the storage unit 140 stores a resistance factor lookup table that defines the resistance factor R _{ch @ SOC} for each state of charge of the secondary battery B.

In a more preferred example, the resistance factor lookup table may be defined for each temperature of the secondary battery (B). In this case, the resistance factor R _{ch @ SOC} may be mapped by the temperature of the secondary battery B and the state of charge.

The resistance factor lookup table is previously defined using the algorithm described with reference to FIGS. 3 and 4, and a method for generating it through experiments has been described above. In addition, when storing the resistance factor lookup table generated through the experiment in the storage unit 140, conventional data replication techniques may be used.

The sensor unit 110 is electrically coupled to send and receive electrical signals with the control unit 120.

The sensor unit 110, under the control of the control unit 120, is input to the secondary battery B or a voltage applied between the positive electrode and the negative electrode of the secondary battery B at a time interval, or the secondary battery B The current output from the temperature and the temperature of the secondary battery B are repeatedly measured and the measured voltage, current and temperature are provided to the control unit 120. Here, the voltage, current and temperature may be measured at the same time point or at different time points.

The sensor unit 110 may include a voltage measuring unit for measuring the voltage of the secondary battery B, a current measuring unit for measuring the current of the secondary battery B, and a temperature of the secondary battery B. It may include a temperature measuring unit for.

In an example, the voltage measuring unit may include a conventional voltage measuring circuit 111 capable of measuring the voltage of the secondary battery B based on the ground GND. In addition, the current measuring unit may include a sense resistor 112 for measuring the magnitude of the current. In addition, the temperature measuring unit may include a thermocouple 113 for measuring the temperature of the secondary battery.

The control unit 120 may estimate the state of charge of the secondary battery B after receiving the measurement results of the voltage, current, and temperature of the secondary battery B from the sensor unit 110.

In an example, the control unit 120 may estimate the state of charge of the secondary battery B by ampere counting. That is, the control unit 120 may estimate the state of charge of the secondary battery B by integrating the current measured by the sensor unit 110 over time.

In order to estimate the state of charge of the secondary battery B by the current integration method, an initial value of the state of charge is required. The initial value of the state of charge may be determined by measuring the open voltage of the secondary battery B.

That is, the control unit 120 controls the sensor unit 110 before the operation of the secondary battery B to measure the open voltage and temperature, and the OCV-SOC lookup table stored in the storage unit 140. The charging state corresponding to the measured opening voltage and temperature may be determined as an initial value. The OCV-SOC lookup table has a data structure capable of mapping charge states by open voltage and temperature.

In another example, the control unit 120 may estimate the state of charge of the secondary battery B using an extended Kalman filter. At this time, the voltage, current, and temperature measured by the sensor unit 110 may be used. Techniques for estimating state of charge using an extended Kalman filter are well known in the art. As an example, the techniques disclosed in US7446504, US7589532, etc. may be utilized, and the contents disclosed in the above documents may be incorporated as part of the present invention.

The control unit 120 may estimate the charge output using the resistance factor lookup table stored in the storage unit 140 while the secondary battery B is being charged.

That is, the control unit 120 identifies the resistance factor lookup table corresponding to the measured temperature of the secondary battery B, and _selects the resistance factor R _{ch @ SOC} corresponding to the state of charge estimated from the identified resistance factor lookup table. The charge output of the rechargeable battery B may be estimated by the following equation 3 using the determined resistance factor R _{ch @ SOC} and the measured current of the rechargeable battery B.

<Equation 3>

P _ch = R _{ch @ SOC} × I ²

In the above equation, P ^ch is the charging output of the secondary battery B, R _{ch @ SOC} is the resistance factor corresponding to the temperature and state of charge of the secondary battery B, and I is the measurement of the secondary battery B Current corresponds to the magnitude of the charging current.

Since the charging output calculated by Equation 3 is calculated using a current that is easy to measure, there is an advantage that the error is small. In addition, while the secondary battery B is being charged, accurate voltage measurement is difficult due to the internal resistance of the secondary battery B and the polarization voltage. Therefore, a method of calculating the charging output using the current is more preferable.

The charging output calculated by Equation 3 is a resistance factor R _{ch @ SOC} determined in advance using a voltage response characteristic that appears at the initial stage of charging when the charging current measured by the sensor unit 110 is applied to the secondary battery B. It was determined using.

Therefore, when the charging of the secondary battery B is controlled based on the charging output, it is possible to prevent the voltage or the charging current of the secondary battery B from exceeding the charge upper limit condition.

That is, since excessive charging current is applied to the secondary battery B or the secondary battery B may be prevented from being charged in an overvoltage state, safer charging control is possible.

The control unit 120 may store the estimated charge output of the secondary battery B and the change history of the charge output in the storage unit 140.

In another aspect, the charge output estimating apparatus 100 may further include a display unit 150. The display unit 150 is not particularly limited as long as it can display the charging output estimated by the control unit 120 using a GUI interface such as numbers, letters, and graphics.

As an example, the display unit 150 may be a liquid crystal display, an LED display, an OLED display, an E-INK display, a flexible display, or the like.

The display unit 150 may be directly or indirectly connected to the control unit 120. When the latter method is adopted, the display unit 150 may be located in an area physically separated from the area in which the control unit 120 is located. A third control unit is interposed between the display unit 150 and the control unit 120 to receive the information to be displayed on the display unit 150 from the control unit 120. The display unit 150 can be displayed. To this end, the third control unit and the control unit 120 may be connected to exchange data.

In another aspect, the charge output estimating apparatus 100 may further include a communication interface 160. The communication interface 160 supports transmission and reception of data between the control unit 120 and the charger controller 180 that controls the operation of the charger 130.

In this example, the control unit 120 may transmit the estimated charging output of the secondary battery B to the charger controller 180. Then, the charger controller 180 may control the charging operation of the secondary battery B using the charging output of the secondary battery B within a charging upper limit condition with a certain safety margin.

The control unit 120 may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, or the like, which are known in the art, to execute the various control logics described above. It may include. In addition, when the control logic is implemented in software, the control unit 120 may be implemented as a set of program modules. In this case, the program module may be stored in a memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor through various well known computer components. In addition, the memory may be included in the storage unit 140 of the present invention. In addition, the memory refers to a device that stores information regardless of the type of device, and does not refer to a specific memory device.

It is apparent that the control logics of the above-described control unit 120 may constitute a process of the method of estimating the charge output of the secondary battery according to the embodiment of the present invention.

9 is a flowchart illustrating a sequential flow of a method of estimating charge output of a secondary battery according to an exemplary embodiment of the present invention.

First, in step S200, the control unit 120 loads the resistance factor lookup table from the storage unit 140. The resistance factor lookup table defines the resistance factor R _{ch @ SOC} of the secondary battery for each charging state. Preferably, the resistance factor lookup table may be defined separately according to temperature conditions.

Subsequently, the control unit 120 measures the voltage, current, and temperature of the secondary battery through the sensor unit 110 in step S210, stores the stored value in the storage unit 140, and estimates the state of charge of the secondary battery in step S220. .

Subsequently, the control unit 120 identifies, in step S230, the resistance lookup factor table corresponding to the measured temperature and uses the identified resistance factor lookup table to determine the resistance factor R _{ch @ SOC} corresponding to the estimated state of _charge . Decide

Subsequently, the control unit 120 estimates the charge output P ^ch of the secondary battery using the resistance factor R _{ch @ soc} and the measured charge current I determined using the above equation (3).

Optionally, the control unit 120 may store the estimated charging output in the storage unit 140, display it on the display unit 150, or transmit it externally through the communication interface 160 in step S250.

At least one of various control logics of the control unit 120 may be combined, and the combined control logics may be written in a computer readable code system and stored in a computer readable recording medium. The recording medium is not particularly limited as long as it is accessible by a processor included in the computer. In one example, the recording medium includes at least one selected from the group consisting of a ROM, a RAM, a register, a CD-ROM, a magnetic tape, a hard disk, a floppy disk, and an optical data recording device. In addition, the code system may be distributed and stored and executed in a networked computer. In addition, functional programs, code and code segments for implementing the combined control logics can be easily inferred by programmers in the art to which the present invention pertains.

In describing the various embodiments of the present invention, elements designated as 'unit' should be understood to be functionally separated elements rather than physically separated elements. Thus, each component may be selectively integrated with other components or each component may be divided into subcomponents for efficient execution of control logic (s). However, it will be apparent to those skilled in the art that the integrated or divided components should also be interpreted as being within the scope of the present invention, provided that the functional identity can be recognized even if the components are integrated or divided.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

According to one aspect of the invention, it is possible to easily determine the resistance factor used to estimate the charging output of the secondary battery within the safety margin.

According to another aspect of the present invention, the charging output of the secondary battery can be reliably estimated with a safety margin from the charging upper limit condition of the secondary battery.

According to another aspect of the present invention, it is possible to prevent the voltage or the charging current of the secondary battery from excessively increasing during the charge control process of the secondary battery.

Claims (19)

1. (a) measuring a plurality of charging initial voltage data and a plurality of charging end voltage data according to the change of the magnitude of the charging current according to the temperature and the charging state of the secondary battery and storing them in the memory;

   (b) determining a charging end I-V profile from the plurality of charging end voltage data and determining an intersection point at which the charging end I-V profile meets a boundary corresponding to a charging upper limit current or a charging upper limit voltage preset as a charging upper limit condition;

   (c) determining a charging initial I-V profile from the plurality of charging initial voltage data and determining a first derivative value for the charging initial I-V profile calculated based on the current value of the intersection; And

   and (d) determining the determined primary differential value as a resistance factor corresponding to a temperature and a state of charge of the secondary battery.
2. The method of claim 1,

   Defining a resistance factor lookup table in the memory such that the resistance factor of the secondary battery can be mapped by the temperature and state of charge of the secondary battery; And

   And storing the determined resistance factor in the defined resistance factor lookup table.
3. The method of claim 1,

   The initial charging voltage data is voltage data measured within 1 second after the charging current is applied to the secondary battery,

   The charging end voltage data is a voltage factor measurement method of the secondary battery, characterized in that the voltage data measured when the application of the charging current to the secondary battery is finished.
4. According to claim 1, wherein the step (a),

   Maintaining a constant temperature of the secondary battery;

   Conducting a charging test for applying a plurality of charging currents having different sizes to the secondary battery for each state of charge of the secondary battery; And

   And measuring and storing a charge initial voltage and a charge end voltage of the secondary battery each time a respective charging current is applied to the secondary battery.
5. The method of claim 4, wherein

   When the magnitude of the charging current applied to the secondary battery is greater than the charging upper limit current or the charging end voltage of the secondary battery measured most recently is greater than the charging upper limit voltage, the resistance test of the secondary battery is stopped. How to decide.
6. A storage unit in which a resistance factor lookup table capable of referring to the resistance factor by the temperature and the state of charge of the secondary battery is stored in advance;

   A sensor unit measuring a charging current and a temperature of the secondary battery when the secondary battery is being charged; And

   Determine a state of charge of the secondary battery, determine a resistance factor corresponding to the determined state of charge and the measured temperature with reference to the resistance factor lookup table, and charge the secondary battery from the determined resistance factor and the measured charging current; A control unit for estimating the output;

   When the secondary battery has a predetermined temperature and a state of charge, the resistance factor is calculated for the initial charge IV profile calculated from the current value of the intersection point where the end of charge IV profile according to the change of the magnitude of the charge current meets the boundary set as the upper limit of charge. Charge output estimating apparatus for a secondary battery, characterized in that the first derivative value.
7. The method of claim 6,

   The boundary line is a boundary line indicating the charge upper limit current and the charge upper limit voltage, the charge output estimation device of the secondary battery.
8. The method of claim 6,

   The initial IV profile is a graph defining a correlation between the charging current applied to the secondary battery and the voltage measured immediately after the corresponding charging current is applied when a plurality of different charging currents are applied to the secondary battery. A charge output estimation device for a secondary battery.
9. The method of claim 8,

   And a plurality of voltage data constituting the initial charging I-V profile are voltage data measured within 1 second after each charging current is applied to the secondary battery.
10. The method of claim 6,

    The charging end IV profile defines a correlation between the charging current applied to the secondary battery and the voltage measured when the application of the charging current is terminated when a plurality of charging currents having different sizes are applied to the secondary battery. Charge output estimating apparatus for a secondary battery characterized by the above-mentioned.
11. The method of claim 6,

    And the control unit is configured to store the estimated charging output in the storage unit.
12. The method of claim 6,

    A display unit connected to the control unit,

    And the control unit displays the estimated charge output through the display unit.
13. The method of claim 6,

    Further comprising a communication interface connected with the control unit,

    And the control unit transmits the estimated charge output to the outside through the communication interface.
14. Providing a resistance factor lookup table capable of referring to the resistance factor by temperature and state of charge of the secondary battery;

    Measuring a charging current and a temperature of the secondary battery when the secondary battery is being charged;

    Determining a state of charge of the secondary battery;

    Determining a resistance factor corresponding to the determined state of charge and the measured temperature with reference to the resistance factor lookup table; And

    Estimating a charge output of a secondary battery from the determined resistance factor and the measured charge current;

    When the secondary battery has a predetermined temperature and a state of charge, the resistance factor is calculated for the initial charge IV profile calculated from the current value of the intersection point where the end of charge IV profile according to the change of the magnitude of the charge current meets the boundary set as the upper limit of charge. A charge output estimation method of a secondary battery, characterized in that the first derivative value.
15. The method of claim 14,

    The boundary line is a boundary line indicating the charge upper limit current and the charge upper limit voltage, the charge output estimation method of a secondary battery.
16. The method of claim 14,

    The initial IV profile is a graph defining a correlation between the charging current applied to the secondary battery and the voltage measured immediately after the corresponding charging current is applied when a plurality of different charging currents are applied to the secondary battery. A method of estimating the charge output of a secondary battery characterized by the above-mentioned.
17. The method of claim 16,

    And a plurality of voltage data constituting the initial charging I-V profile are voltage data measured within one second after each charging current is applied to the secondary battery.
18. The method of claim 14,

    The charging end IV profile defines a correlation between the charging current applied to the secondary battery and the voltage measured when the application of the charging current is terminated when a plurality of charging currents having different sizes are applied to the secondary battery. The charging output estimation method of a secondary battery characterized by the above-mentioned.
19. The method of claim 14,

    And storing, displaying, or transmitting the estimated charge output.

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