KR102538419B1 - Method of measuring internal resistance of battery by current cut-off and method of measuring state of charge using same - Google Patents

Abstract

Disclosed are a method for measuring the internal resistance of a battery by a current cut-off method and a method for measuring the remaining capacity of a battery using the same. The internal resistance measuring method of the battery includes (a) measuring an initial cut-off voltage (V ₀ ) of the battery when the current (I ₀ ) of the battery is cut off while charging or discharging the battery; (b) measuring a first voltage (V ₁ ) of the battery when a first time elapses after the current is cut off; (c) measuring a second voltage (V ₂ ) of the battery when a second time elapses after the current is cut off; And (d) an internal including ohmic resistance and polarization resistance using the cut-off initial voltage (V ₀ ), the first voltage (V ₁ ) and the second voltage (V ₂ ). By including the step of calculating the resistance, the ohmic resistance and polarization resistance of the battery can be measured, and the remaining capacity of the battery can be measured using this.

Description

Method for measuring internal resistance of battery by current cut-off method and method for measuring residual capacity of battery using the same

The present invention relates to a method for measuring the internal resistance of a battery by a current cut-off method and a method for measuring the remaining capacity of a battery using the same, and more particularly, by cutting off the current after charging or discharging the battery and measuring the voltage over a certain period of time. It relates to a method of measuring internal resistance and using it to measure remaining capacity of a battery.

It is important to understand the characteristics of the resistance component of the battery in order to understand the degree of deterioration of battery packs for electric vehicles and ESS and to accurately identify the cause of deterioration. Representative methods for measuring the internal resistance of a battery include a current blocking method and an AC impedance method.

The AC impedance measurement method measures the resistance value of a battery at a specific frequency to determine its characteristics. Equipment for simultaneously inputting alternating current as much as the number of is required, which complicates the equipment configuration and increases cost.

On the other hand, the current blocking method has a relatively simple analysis device compared to the AC impedance measurement method, and can quickly measure resistance within a few seconds by observing a voltage change that appears instantaneously when current is cut off. In addition, the current blocking method has the advantage of being able to measure the internal resistance without additional equipment because it is possible to measure the voltage of each unit cell in connection with the BMS of the battery pack for electric vehicles and ESS.

However, since the current blocking method can measure only the ohmic resistance, there is a limit to identifying the cause of performance deterioration and predicting the state of the battery pack.

Therefore, it is necessary to develop a method for identifying the cause of performance deterioration of a battery pack and predicting its state.

An object of the present invention is to solve the above problems, and to provide a method capable of separately measuring ohmic resistance and polarization resistance inside a battery.

Another object of the present invention is to provide a method for identifying the cause of performance deterioration of a battery pack and predicting its condition.

According to one aspect of the present invention, (a) measuring an initial cut-off voltage (V ₀ ) of the battery when the current (I ₀ ) of the battery is cut off while charging or discharging the battery; (b) measuring a first voltage (V ₁ ) of the battery when a first time elapses after the current is cut off; (c) measuring a second voltage (V ₂ ) of the battery when a second time elapses after the current is cut off; And (d) an internal including ohmic resistance and polarization resistance using the cut-off initial voltage (V ₀ ), the first voltage (V ₁ ) and the second voltage (V ₂ ). There is provided a method for measuring the internal resistance of a battery including; calculating the resistance.

In addition, the ohmic resistance is electrically generated resistance, and the electrically generated resistance may include at least one selected from the group consisting of electrode internal resistance, electrolyte internal resistance, and contact resistance.

In addition, the polarization resistance is resistance generated from an electrochemical reaction, and the resistance generated from the electrochemical reaction may include at least one selected from the group consisting of charge transfer resistance, ion diffusion resistance, and activation resistance.

In addition, the first voltage (V ₁ ) is a voltage obtained by recovering the ohmic voltage (V _ohmic ) loss caused by the ohmic resistance in the cut-off initial voltage (V ₀ ), and the second voltage (V ₂ ) is the first voltage The polarization voltage (V _pol ) loss caused by the polarization resistance at (V ₁ ) may be a recovered voltage.

Also, the voltage at which the polarization voltage loss is recovered may be an open circuit voltage (V _oc ).

In addition, the first time may be greater than 0 seconds or less than 1 second (0<t ₁ (sec) ≤ 1).

Also, the second time period may be greater than 1 second to less than 3,600 seconds (1<t ₂ (sec) ≤ 3,600).

In addition, the step (d) may include (d-1) calculating an ohmic resistance using the cut-off initial voltage (V ₀ ) and the first voltage (V ₁ ); and (d-2) calculating polarization resistance using the first voltage (V ₁ ) and the second voltage (V ₂ ).

In addition, in the step (d-1), the ohmic resistance may be calculated using Equation 1 below.

[Equation 1]

Ohmic resistance = (｜V ₁ - V ₀ ｜)/I ₀

In Equation 1 above,

V ₁ is a first voltage;

V ₀ is the cut-off initial voltage,

I ₀ is the current at break.

In addition, in the step (d-2), the polarization resistance may be calculated using Equation 2 below.

[Equation 2]

Polarization resistance = (｜V ₂ - V ₁ ｜)/I ₀

In Equation 2 above,

V ₂ is a second voltage;

V ₁ is a first voltage;

I ₀ is the current at break.

In addition, the method for measuring the internal resistance of the battery may further include, after the step (d-2), (d-3) calculating the total internal resistance of the battery by adding the ohmic resistance and the polarization resistance. .

Also, the battery may be a lithium secondary battery.

According to another aspect of the present invention, an apparatus for measuring internal resistance of a battery using the method for measuring internal resistance of a battery is provided.

According to another aspect of the present invention, (1) measuring the initial capacity of the battery before charging and discharging; (2) measuring the internal resistance of the battery using the method for measuring the internal resistance of the battery; and (3) measuring a state of charge (SOC) of the battery using the internal resistance, wherein the internal resistance includes ohmic resistance and polarization resistance. A method is provided.

In addition, the method for measuring the remaining capacity of the battery may further include, prior to the step (2), (2') charging and discharging the battery singly or multiple times.

In addition, the step (3) may be to measure the remaining capacity of the battery using the internal resistance and Equation 3 below.

[Equation 3]

Battery remaining capacity [Ah] = α - β × R _ohmic - γ × R _pol

In Equation 3 above,

α is a constant with units of Ah.

β and γ are constants each independently having units of Ah/Ω,

R _ohmic is the ohmic resistance,

R _pol is the polarization resistance.

In addition, the α, β, and γ may be independently obtained by linear regression.

In addition, the method for measuring the remaining battery capacity may further include, after the step (3), (4) estimating the remaining life of the battery from the remaining battery capacity.

In the method for measuring the internal resistance of a battery according to the present invention, the ohmic resistance and polarization resistance inside the battery can be separately measured by charging or discharging the battery using the current blocking method, then cutting off the current and measuring the voltage over a certain period of time.

In addition, the method for measuring the remaining capacity of a battery according to the present invention includes a method for measuring the internal resistance of the battery, so that the cause of performance deterioration of the battery pack can be identified and the state can be predicted.

Since these drawings are for reference in explaining exemplary embodiments of the present invention, the technical spirit of the present invention should not be construed as being limited to the accompanying drawings.
1 is a graph of voltage loss (overvoltage) occurring at electrodes during battery charging.
2 is a graph of open-circuit voltage (V _OC ) and terminal voltage (V _t ) observed during battery charging.
3 is a graph of voltage loss (overvoltage) occurring at electrodes during battery discharge.
4 is a graph of open-circuit voltage (V _OC ) and terminal voltage (V _t ) observed during battery discharge.
5 shows a change in voltage when the current is cut off during battery charging.
6 illustrates a change in voltage when current is cut off during battery discharge.
7 shows the pouch battery and materials used in the examples.
FIG. 8 is an observation of a change in voltage during current cut-off and battery idle time after discharging the charged battery (pouch battery of FIG. 7) to 3V.
FIG. 9 shows the total internal resistance of the battery for each cycle measured according to an embodiment of the present invention, and the capacity and operating temperature of the battery for each cycle.
10 shows the ohmic resistance, polarization resistance, and total internal resistance of the battery for each cycle measured according to an embodiment of the present invention, and the operating temperature of the battery for each cycle.
11 illustrates a correlation between battery internal resistance (ohmic resistance, polarization resistance, and total internal resistance) measured according to an embodiment of the present invention and battery capacity.
12 shows predicted remaining capacity of a battery and measured values according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

However, the following description is not intended to limit the present invention to specific embodiments, and in describing the present invention, if it is determined that the detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. .

Terms used herein are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, or combination thereof described in the specification, but one or more other features or It should be understood that the presence or addition of numbers, steps, operations, elements, or combinations thereof is not precluded.

Also, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention.

In addition, when a component is referred to as being “formed” or “layered” on another component, it may be formed or laminated directly on the front or one side of the surface of the other component, but intermediate It should be understood that other components may be further present.

Hereinafter, a method for measuring the internal resistance of a battery according to the current blocking method and a method for measuring the remaining capacity of a battery using the method according to the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

1 is a graph of voltage loss (overvoltage) occurring at electrodes during battery charging, and FIG. 2 is a graph of open circuit voltage (V _OC ) and terminal voltage (V _t ) observed during battery charging.

Referring to FIG. 1 , the horizontal axis represents the charge capacity (Ah), the vertical axis represents the potential inside the battery, and the component of the voltage loss of the battery being charged is caused by the resistance component generated from the positive electrode and the negative electrode. As shown in FIG. 2, a charging voltage higher than the open-circuit voltage of the battery is measured by the voltage loss generated at each electrode. The measured terminal voltage (V _t ) is the battery's open-circuit voltage (V _oc ), the ohmic voltage (V _ohmic ) loss caused by the ohmic resistance (R _ohmic ), and the polarization voltage (V ) caused by the polarization resistance (R _pol ). _pol ) loss and can have the relationship of Equation 4 below.

[Equation 4]

V _t = V _oc + V _ohmic + V _pol

3 is a graph of voltage loss (overvoltage) occurring at electrodes during battery discharge, and FIG. 4 is a graph of open-circuit voltage (V _OC ) and terminal voltage (V _t ) observed during battery discharge.

Referring to FIGS. 3 and 4, even when the battery is discharged, a voltage loss occurs due to a resistance component similarly to the case of charging, and the observed terminal voltage (V _t ) may have the relationship of Equation 5.

[Equation 5]

V _t = V _oc - V _ohmic - V _pol

5 shows a change in voltage when current is cut off during battery charging, and FIG. 6 shows a change in voltage when current is cut off during battery discharge.

Referring to FIGS. 5 and 6 , it can be seen that the voltage of the battery from which the current is cut off recovers to the open-circuit voltage (V _oc ) over time. When the current is cut off, the sudden voltage change in the initial unit of tens to hundreds of microseconds means that the ohmic voltage (V _ohmic ) loss generated by the ohmic resistance (R _ohmic ) recovers linearly as soon as the current is cut off. After the initial rapid voltage change, the loss of polarization voltage (V _pol ) caused by electrochemical reactions such as charge transfer resistance (R _ct ), ion diffusion resistance (R _d ), and activation resistance slowly recovers sequentially over several minutes to several tens of minutes. It reaches the open-circuit voltage (V _oc ).

Ohmic resistance (R _ohmic ) and polarization resistance (R _pol ) can be calculated. For example, by detecting the first voltage (V ₁ ) immediately before current blocking, the second voltage (V ₂ ) after 500 ms of current blocking, and the third voltage (V ₃ ) after 10 min, the first voltage (V ₁ ) An ohmic voltage (V _ohmic ) loss may be calculated using a difference between V and the second voltage (V ₂ ). In addition, the polarization voltage (V _pol ) loss may be calculated as a difference between the second voltage (V ₂ ) and the third voltage (V ₃ ).

[Equation 6]

R = V/I

In Equation 6 above,

R is resistance, V is voltage, and I is current.

Referring to Figures 5 and 6, the present invention includes (a) measuring an initial cut-off voltage (V ₀ ) of the battery when the current (I ₀ ) of the battery is cut off while charging or discharging the battery; (b) measuring a first voltage (V ₁ ) of the battery when a first time elapses after the current is cut off; (c) measuring a second voltage (V ₂ ) of the battery when a second time elapses after the current is cut off; And (d) an internal including ohmic resistance and polarization resistance using the cut-off initial voltage (V ₀ ), the first voltage (V ₁ ) and the second voltage (V ₂ ). It provides a method for measuring the internal resistance of a battery including; calculating the resistance.

In addition, the ohmic resistance may be electrically generated resistance, and the electrically generated resistance may include at least one selected from the group consisting of electrode internal resistance, electrolyte internal resistance, and contact resistance.

Further, the polarization resistance may be resistance generated from an electrochemical reaction, and the resistance generated from the electrochemical reaction may include at least one selected from the group consisting of charge transfer resistance, ion diffusion resistance, and activation resistance.

In addition, the first voltage (V ₁ ) is a voltage obtained by recovering the ohmic voltage (V _ohmic ) loss caused by the ohmic resistance in the cut-off initial voltage (V ₀ ), and the second voltage (V ₂ ) is the first voltage The polarization voltage (V _pol ) loss caused by the polarization resistance at (V ₁ ) may be a recovered voltage.

Also, the voltage at which the polarization voltage loss is recovered may be an open circuit voltage (V _oc ).

In addition, the first time may be greater than 0 seconds to less than 1 second (0<t ₁ (sec) ≤ 1), preferably 0.3 seconds. When the first time (t ₁ ) is 0 seconds or less, a second voltage having the same value as the first voltage is obtained, and the voltage recovered from the ohmic voltage loss caused by the ohmic resistance cannot be known, which is undesirable and may exceed 1 second. In this case, not only the voltage in which the ohmic voltage loss caused by the ohmic resistance is recovered, but also the voltage in which the polarization voltage loss caused by the polarization resistance is recovered, so it is difficult to derive an accurate value.

In addition, the second time (t ₂ ) may be greater than 1 second to 3,600 seconds or less (1<t ₂ (sec) ≤ 3,600), preferably 600 to 3,600 seconds (600 ≤ t ₂ (sec) ≤ 3,600 ) can be. If the second time is longer than 1 second, not only the voltage recovered from the polarization voltage loss caused by the polarization resistance but also the voltage recovered from the ohmic voltage loss caused by the ohmic resistance is measured together, making it difficult to derive an accurate value. If it exceeds, it is undesirable because most of the voltage loss is recovered, and since the change in voltage value is insignificant, no meaningful results are obtained over time.

In addition, the step (d) may include (d-1) calculating an ohmic resistance using the cut-off initial voltage (V ₀ ) and the first voltage (V ₁ ); and (d-2) calculating polarization resistance using the first voltage (V ₁ ) and the second voltage (V ₂ ).

In addition, the ohmic resistance may be calculated using Equation 1 below.

[Equation 1]

Ohmic resistance = (｜V ₁ - V ₀ ｜)/I ₀

In Equation 1 above,

V ₁ is a first voltage;

V ₀ is the cut-off initial voltage,

I ₀ is the current at break.

In addition, in the step (d-2), the polarization resistance may be calculated using Equation 2 below.

[Equation 2]

Polarization resistance = (｜V ₂ - V ₁ ｜)/I ₀

In Equation 2 above,

V ₂ is a second voltage;

V ₁ is a first voltage;

I ₀ is the current at break.

In addition, the method for measuring the internal resistance of the battery may further include, after the step (d-2), (d-3) calculating the total internal resistance of the battery by adding the ohmic resistance and the polarization resistance. .

Also, the battery may be a lithium secondary battery.

The present invention provides a device for measuring internal resistance of a battery using the method for measuring internal resistance of a battery.

The present invention includes (1) measuring an initial capacity of a battery before charging and discharging; (2) measuring the internal resistance of the battery using the method for measuring the internal resistance of the battery; and (3) measuring a state of charge (SOC) of the battery using the internal resistance, wherein the internal resistance includes ohmic resistance and polarization resistance. provides a way

In addition, the method for measuring the remaining capacity of the battery may further include, prior to the step (2), (2') charging and discharging the battery singly or multiple times.

In addition, the step (3) may be to measure the remaining capacity of the battery using the internal resistance and Equation 3 below.

[Equation 3]

Battery remaining capacity [Ah] = α - β × R _ohmic - γ × R _pol

In Equation 3 above,

α is a constant with units of Ah.

β and γ are constants each independently having units of Ah/Ω,

R _ohmic is the ohmic resistance,

R _pol is the polarization resistance.

In addition, the α, β, and γ may be independently obtained by linear regression. Specifically, α, β, and γ vary depending on the type and size of the battery, and their values can be obtained through a linear regression method.

In addition, the method for measuring the remaining battery capacity may further include, after the step (3), (4) estimating the remaining life of the battery from the remaining battery capacity.

[Example]

Hereinafter, a preferred embodiment of the present invention will be described. However, this is for illustrative purposes and the scope of the present invention is not limited thereby.

Example 1: Measuring the internal resistance of a battery

7 shows the pouch battery and materials used in the examples. A 24 A-class pouch battery as shown in FIG. 7 was subjected to continuous charge and discharge experiments under the charge and discharge conditions shown in Table 1 below, and the continuous experiments were conducted by adjusting the operating temperature of the battery during the cycle.

cycle section operating voltage range charging current discharge current operating temperature 1 to 580 3.0 to 4.2V 24 A (1 C) 48 A (2 C) 40~45℃ 580 to 1,000 30 ~ 40 ℃ 1,000 to 1,167 43 ~ 44 ℃

FIG. 8 is an observation of a change in voltage during current cut-off and battery idle time after discharging the charged battery (pouch battery of FIG. 7) to 3V.

Referring to FIG. 8, when the discharge applied current (I ₀ ) of the battery is blocked and changed to 0, the voltage (V ₀ ) observed in the battery is quickly recovered and changed to the voltage (V ₁ ) after 0.3 seconds and after 10 minutes It can be seen that the voltage (V ₂ ) rises to a level of 90% or more of the open-circuit voltage. At this time, the internal ohmic resistance (R _ohmic ) can be calculated through Equation 1 below by measuring the amount of change in applied current and voltage, and the internal polarization resistance (R _pol ) can be calculated through Equation 2.

[Equation 1]

Ohmic resistance = (｜V ₁ - V ₀ ｜)/I ₀

[Equation 2]

Polarization resistance = (｜V ₂ - V ₁ ｜)/I ₀

In Equations 1 and 2 above,

V ₂ is the voltage measured 10 minutes after the current is cut off;

V ₁ is the measured voltage after 0.3 seconds of current interruption,

V ₀ is the voltage measured when the current is cut off,

I ₀ is the discharge applied current.

Example 2: Confirmation of relationship between internal resistance measurement of battery for each cycle and discharge capacity of battery

FIG. 9 shows the total internal resistance of the battery for each cycle measured according to an embodiment of the present invention, and the capacity and operating temperature of the battery for each cycle.

Referring to FIG. 9 , it can be seen that the total internal resistance of the battery for each cycle measured according to the embodiment increases or decreases according to the operating temperature of the battery and gradually increases as deterioration progresses. In addition, it can be confirmed that the discharge capacity of the battery has a negative correlation with the measured total internal resistance of the battery.

FIG. 10 shows the ohmic resistance, polarization resistance, and total internal resistance of the battery for each cycle measured according to the embodiment of FIG. 9 and the operating temperature of the battery for each cycle.

Referring to FIG. 10 , it can be seen that the total internal resistance decreases due to the activation of the battery in the initial cycle. After about 50 cycles, it can be seen that the ohmic resistance (R _ohmic ) of the battery increases linearly as the cycle progresses, and the amount of change according to the change in operating temperature of the battery is not large. On the other hand, in the case of the polarization resistance (R _pol ), it can be seen that the deterioration rate changes faster than the ohmic resistance and changes sensitively to the battery operating temperature. Therefore, it can be predicted that the performance of the battery of the above embodiment is degraded due to deterioration of the lithium ion insertion/desorption or ion diffusion rate due to deterioration occurring at the electrode.

Example 3: Battery state prediction based on internal resistance data

11 illustrates a correlation between battery internal resistance (ohmic resistance, polarization resistance, and total internal resistance) measured according to an embodiment of the present invention and battery capacity.

Referring to FIG. 11 , it can be seen that internal resistance and discharge capacity have a strong negative correlation. Therefore, the life of the battery according to the resistance was predicted by linear regression using the internal resistance of the battery.

In Example 2, based on the battery capacity and battery internal resistance data of the 50 to 150 cycle period, the linear regression method was used to calculate the correlation coefficient between the battery health state and the ohmic resistance and polarization resistance, and Equation 7 below was derived.

[Equation 7]

Battery remaining capacity [Ah] = α - β × R _ohmic - γ × R _pol

In Equation 7 above,

α is 26.2255 Ah.

β is 0.5368 Ah/mΩ;

γ is 0.7765 Ah/mΩ;

R _ohmic is the ohmic resistance,

R _pol is the polarization resistance.

12 shows predicted remaining battery capacity and measured values according to an embodiment of the present invention. In detail, the remaining capacity of the battery according to the embodiment of the present invention is the result of estimating the state of health of the battery for a total of 1,167 cycles based on Equation 3 and the ohmic resistance and polarization resistance measured according to the embodiment of the present invention.

Referring to FIG. 12 , it was confirmed that the average absolute error (MAPE) of the battery remaining capacity predicted according to an embodiment of the present invention compared to the measured value was 0.51%, which is a significant estimated value.

The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (18)

(1) measuring the initial capacity of the battery before charging and discharging;
(2) measuring the internal resistance of the battery using a method for measuring the internal resistance of the battery; and
(3) measuring a state of charge (SOC) of the battery using the internal resistance;
The internal resistance includes ohmic resistance and polarization resistance,
The step (3) is to measure the remaining capacity of the battery using the internal resistance and Equation 3 below,
The method for measuring the internal resistance of the battery in step (2) is
(a) measuring an initial cut-off voltage (V ₀ ) of the battery when the current (I ₀ ) of the battery is cut off while charging or discharging the battery;
(b) measuring a first voltage (V ₁ ) of the battery when a first time elapses after the current is cut off;
(c) measuring a second voltage (V ₂ ) of the battery when a second time elapses after the current is cut off; and
(d) Internal resistance including ohmic resistance and polarization resistance using the cut-off initial voltage (V ₀ ), the first voltage (V ₁ ) and the second voltage (V ₂ ) Calculating; Method for measuring remaining battery capacity, including:
[Equation 3]
Battery remaining capacity [Ah] = α - β × R _ohmic - γ × R _pol
In Equation 3 above,
α is a constant with units of Ah.
β and γ are constants each independently having units of Ah/Ω,
R _ohmic is the ohmic resistance,
R _pol is the polarization resistance. According to claim 1,
The ohmic resistance is electrically generated resistance,
The method for measuring remaining capacity of a battery, characterized in that the electrically generated resistance includes at least one selected from the group consisting of internal resistance of an electrode, internal resistance of an electrolyte, and contact resistance. According to claim 1,
The polarization resistance is resistance generated in an electrochemical reaction,
A method for measuring remaining capacity of a battery, characterized in that the resistance generated in the electrochemical reaction includes at least one selected from the group consisting of charge transfer resistance, ion diffusion resistance, and activation resistance. According to claim 1,
The first voltage (V ₁ ) is a voltage obtained by recovering the loss of the ohmic voltage (V _ohmic ) generated by the ohmic resistance at the initial cut-off voltage (V ₀ );
The second voltage (V ₂ ) is a battery residual capacity measuring method, characterized in that the voltage at which the polarization voltage (V _pol ) loss generated by the polarization resistance in the first voltage (V ₁ ) is recovered. According to claim 4,
A method for measuring remaining capacity of a battery, characterized in that the voltage at which the polarization voltage loss is recovered is an open-circuit voltage (V _oc ). According to claim 1,
The remaining battery capacity measuring method, characterized in that the first time (t ₁ ) is more than 0 seconds to less than 1 second (0 <t ₁ (sec) ≤ 1). According to claim 1,
The second time period (t ₂ ) is greater than 1 second to less than 3,600 seconds (1 <t ₂ (sec) ≤ 3,600) Characterized in that the remaining battery capacity measuring method. According to claim 1,
The step (d)
(d-1) calculating an ohmic resistance using the cut-off initial voltage (V ₀ ) and the first voltage (V ₁ ); and
(d-2) calculating polarization resistance using the first voltage (V ₁ ) and the second voltage (V ₂ ); a method for measuring remaining capacity of a battery, characterized in that it comprises a. According to claim 8,
In the step (d-1), the battery remaining capacity measuring method, characterized in that the ohmic resistance is calculated using Equation 1 below:
[Equation 1]
Ohmic resistance = (｜V ₁ - V ₀ ｜)/I ₀
In Equation 1 above,
V ₁ is a first voltage;
V ₀ is the cut-off initial voltage,
I ₀ is the current at break. According to claim 8,
In the step (d-2), the polarization resistance is calculated using Equation 2 below, characterized in that the battery remaining capacity measuring method:
[Equation 2]
Polarization resistance = (｜V ₂ - V ₁ ｜)/I ₀
In Equation 2 above,
V ₂ is a second voltage;
V ₁ is a first voltage;
I ₀ is the current at break. According to claim 8,
The method for measuring the internal resistance of the battery after the step (d-2),
(d-3) obtaining a total internal resistance of the battery by summing the ohmic resistance and the polarization resistance. According to claim 1,
Battery remaining capacity measuring method, characterized in that the battery is a lithium secondary battery. An apparatus for measuring remaining capacity of a battery using the method for measuring remaining capacity of a battery according to claim 1 . delete According to claim 1,
The method of measuring the remaining capacity of the battery before the step (2),
(2') charging and discharging the battery singly or plural times; delete According to claim 1,
A method for measuring remaining capacity of a battery, characterized in that the α, β, and γ are independently obtained by a linear regression method. According to claim 1,
The method for measuring the remaining capacity of the battery after step (3),
(4) estimating the remaining life of the battery from the remaining battery capacity.

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