Patent Description:
The present invention relates to a device and a method for estimating an impedance spectrum of a battery, and a system including the same, and more particularly, to a device and a method for estimating an impedance spectrum of a battery, and a system including the same, which estimate a cell-unit battery impedance spectrum value from a pack or module-unit battery impedance spectrum measurement value.

In the case of batteries that are operated or reused, it is most important to diagnose a state.

In general, in order to diagnose the state of the battery, a charging state (SOC) and a lifespan state (SOH) of the battery are checked.

In order to check the charging state (SOC) and a lifespan state (SOH) of the battery, an impedance spectrum of a battery cell is measured by electrical impedance spectroscopy (hereinafter, referred to as EIS) in the related art.

In the measurement of the impedance spectrum of the battery cell using the EIS device in the related art, a battery provided in the form of a pack or a module is disassembled in units of a cell, and the impedance spectrum is measured by connecting an EIS measurement device to anode (+) and cathode (-) leads of the respective decomposed cells, as illustrated in <FIG>.

In general, when disassembling the battery pack to a module unit, it is possible to disassemble nondestructive disassembling by removing and disassembling a bus bar used for connection between the battery modules. However, when disassembling the cell unit in the battery module, the battery module should be disassembled by destructing a welded portion of the cell lead using a laser or ultrasonic, so it is difficult to reassemble the cells to the battery module unless the cell lead is replaced, and the battery cells should be reassembled by disassembling the battery cell in units of parts in order to replace the cell lead.

<CIT> provides a battery management apparatus and method, to construct a battery model optimized for a battery cell by obtaining a parameter of the battery model through a neural network and then repeatedly updating the parameter of the battery model based on a difference between an output value of the battery model that reflects the obtained parameter and an actually measured value, and control charging of the battery based on the optimized battery model.

In order to solve the problem, an object of the present invention is to provide a device for estimating an impedance spectrum of a high-efficiency and low-cost battery, which estimates a cell-unit battery impedance spectrum value from an impedance spectrum measurement value of a pack or module-unit battery assembly.

In order to solve the problem, another object of the present invention is to provide a method for estimating an impedance spectrum of a high-efficiency and low-cost battery, which estimates a cell-unit battery impedance spectrum value from an impedance spectrum measurement value of a pack or module-unit battery assembly.

In order to solve the problem, yet another object of the present invention is to provide a system for estimating an impedance spectrum of a high-efficiency and low-cost battery, which estimates a cell-unit battery impedance spectrum value from an impedance spectrum measurement value of a pack or module-unit battery assembly.

In order to achieve the object, a device for estimating an impedance spectrum of a battery cell according to the present invention includes: a memory; and a processor performing at least one command stored in the memory, in which the at least one command includes a command of instructing acquiring an electrical impedance spectroscopy (EIS) measurement value of a battery assembly, a command of instructing modeling an equivalent circuit model (ECM) of the battery assembly, and determining initial parameter values for the equivalent circuit, based on the EIS measurement value, a command of instructing deriving a first parameter value by converting at least one of the initial parameter values by using a predefined conversion constant, and calculating a first cell voltage value based on the first parameter value, a command of instructing acquiring a second cell voltage value measured by charging or discharging the battery cell, a command of instructing comparing the first cell voltage value and the second cell voltage value, and correcting the conversion constant based on a comparison result, a command of instructing calculating a final parameter value based on the corrected conversion constant, and a command of instructing acquiring an EIS estimation value for the battery cell by applying the final parameter value to the equivalent circuit.

Here, the initial parameter value of the equivalent circuit may include a parameter value of at least one of a resistance, a capacitor, an inductor, and a constant phase element (CPE).

Further, the conversion constant may be a constant for converting the equivalent circuit of the battery assembly into the equivalent circuit of the battery cell.

Meanwhile, the command of instructing calculating the first cell voltage value may include a command of instructing converting the equivalent circuit into an impedance function for a time, and acquiring an internal impedance by applying the initial parameter value to the impedance function, and a command of instructing calculating the first cell voltage value by multiplying the internal impedance by a current value.

In this case, the impedance function may be a function of converting the equivalent circuit into a function for the time by using a predefined differential equation.

Meanwhile, the second cell voltage value may be a cell voltage value measured by discharge pulse current of the battery cell.

Further, the command of instructing correcting the conversion constant may include a command of instructing correcting the conversion constant so that a difference between the first cell voltage value and the second cell voltage value is minimized.

In order to achieve the object, a method for estimating an impedance spectrum of a battery cell according to the present invention includes: acquiring an electrical impedance spectroscopy (EIS) measurement value of a battery assembly; modeling an equivalent circuit model (ECM) of the battery assembly, and determining initial parameter values for the equivalent circuit, based on the EIS measurement value; deriving a first parameter value by converting at least one of the initial parameter values by using a predefined conversion constant, and calculating a first cell voltage value based on the first parameter value; acquiring a second cell voltage value measured by charging or discharging for the battery cell; comparing the first cell voltage value and the second cell voltage value, and correcting the conversion constant based on a comparison result; calculating a final parameter value based on the corrected conversion constant; and acquiring an EIS estimation value for the battery cell by applying the final parameter value to the equivalent circuit.

Here, at least one initial parameter value of the equivalent circuit may include a parameter value of at least one of a resistance, a capacitor, an inductor, and a constant phase element (CPE).

Meanwhile, the calculating of the first cell voltage value may include converting the equivalent circuit into an impedance function for a time, and acquiring an internal impedance by applying the initial parameter value to the impedance function, and calculating the first cell voltage value by multiplying the internal impedance by a current value.

Further, the correcting of the conversion constant may include correcting the conversion constant so that a difference between the first cell voltage value and the second cell voltage value is minimized.

In order to achieve the object a system for estimating an impedance spectrum of the battery cell according to the present invention includes: an electrical impedance spectroscopy (EIS) device measuring an impedance spectrum value of a battery assembly; an impedance estimation device of the battery cell calculating a first cell voltage for a battery cell, and acquiring an EIS estimation value of the battery cell; and a battery charging/discharging measurement device measuring a second cell voltage by charging or discharging for the battery cell, in which the impedance estimation device of the battery cell models an equivalent circuit model (ECM) of the battery assembly, and determines at least one of initial parameter values for the equivalent circuit, based on the EIS device measurement value, derives a first parameter value by converting at least one of the initial parameter values by using a predefined conversion constant, and calculates a first cell voltage value based on the first parameter value, corrects the conversion constant by comparing the calculated first cell voltage value, and the second cell voltage value measured by the battery charging/discharging measurement device, calculates a final parameter value based on the corrected conversion constant, and acquires the EIS estimation value for the battery cell by applying the final parameter value to the equivalent circuit.

According to an embodiment and an experimental example of the present invention, a device and a method for estimating an impedance spectrum of a battery, and a system including the same can provide a device and a method for estimating an impedance spectrum of a high-efficiency and low-cost battery, and a system including the same, which estimate a cell-unit battery impedance spectrum value by acquiring measurement values from an Electrical Impedance Spectroscopy (EIS) device measuring an impedance spectrum value of a pack or module-unit battery assembly and a battery charging/discharging measurement device measuring a specific parameter value by charging or discharging by applying pulse current to the pack or module-unit battery assembly to facilitate reassembly and reduce cost by enabling non-destruction measurement without disassembling the battery into the cell unit.

various modifications and various embodiments and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this does not limit the present invention which is defined by the appended claims. In describing each drawing, reference numerals refer to like elements.

Terms including as first, second, A, B, and the like are used for describing various constituent elements, but the constituent elements are not limited by the terms. The terms are used only to discriminate one element from another element. A term 'and/or' includes a combination of a plurality of associated disclosed items or any item of the plurality of associated disclosed items.

It should be understood that, when it is described that a component is "connected to" or "accesses" another component, the component may be directly connected to or access the other component or a third component may be present therebetween. In contrast, when it is described that a component is "directly connected to" or "directly accesses" another component, it is understood that no element is present between the element and another element.

A singular form includes a plural form if there is no clearly opposite meaning in the context. In the present application, it should be understood that the term "include" or "have"indicates that a feature, a number, a step, an operation, a component, a part or the combination thereof described in the specification is present, but does not exclude a possibility of presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof, in advance.

If not contrarily defined, all terms used herein including technological or scientific terms have the same meanings as those generally understood by a person with ordinary skill in the art. Terms which are defined in a generally used dictionary should be interpreted to have the same meaning as the meaning in the context of the related art, and are not interpreted as an ideal meaning or excessively formal meanings unless clearly defined in the present application.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

<FIG> is a block diagram of a system for estimating an impedance spectrum of a battery cell according to an embodiment of the present invention.

Referring to <FIG>, a system S for estimating an impedance spectrum of a battery cell according to an embodiment of the present invention measures charging or discharging data depending on application of an impedance spectrum and pulse current to a battery assembly to estimate a battery cell-unit impedance spectrum value. Here, the battery assembly may include a battery provided in the form of a pack or a module.

According to the embodiment, more specifically, the system S for estimating an impedance spectrum of a battery cell may include an electrical impedance spectroscopy (EIS) device <NUM>, a charging/discharging measurement device <NUM>, and an impedance spectrum estimation device <NUM>.

In this case, the electrical impedance spectroscopy (EIS) device <NUM> may measure an impedance for the battery assembly, the charging/discharging measurement device <NUM> may measure cell voltage of the battery for the battery assembly, and the impedance spectrum estimation device <NUM> may estimate the battery cell-unit impedance spectrum value based on the measurement values measured from the electrical impedance spectroscopy (EIS) device <NUM> and the charging/discharging measurement device <NUM>.

Hereinafter, a feature for each component of the system S for estimating an impedance spectrum of a battery cell will be described in more detail with reference to the drawing.

<FIG> illustrates an image of an electrical impedance spectroscopy (EIS) device according to an embodiment of the present invention.

Referring to <FIG>, the electrical impedance spectroscopy (EIS) device <NUM> is connected to a battery assembly provided in units of a pack or a module to measure the impedance spectrum of the battery assembly.

According to an embodiment, the electrical impedance spectroscopy (EIS) device <NUM> is connected to the anode (+) and cathode (-) leads of the battery pack or module to measure the impedance spectrum of the battery pack or module.

Thereafter, the electrical impedance spectroscopy (EIS) device <NUM> may transmit an impedance spectrum measurement value of the battery pack or module to the impedance spectrum estimation device <NUM> to be described below.

The electrical impedance spectroscopy (EIS) device in the related art measures the impedance spectrum of the battery cell by connecting the battery assembly provided in units of the pack or module to battery cells disassembled in units of the cell, but should destruct a welding portion of a cell lead at the time of disassembling the battery into the cell unit to be disadvantageous in that reassembling after measurement is difficult.

However, the system S for estimating the impedance spectrum of the battery cell according to an embodiment of the present invention may provide a system S for estimating the impedance spectrum of the high-efficiency and low-cost battery cell, which measures the impedance spectrum of the pack or module-unit battery assembly using the electrical impedance spectroscopy (EIS) device <NUM> and estimates the battery cell-unit impedance spectrum value by correcting the measured impedance spectrum to facilitate reassembly by non-destruction measurement, and reduce cost.

<FIG> illustrates an image of a battery charging/discharging measurement device according to an embodiment of the present invention.

Referring to <FIG>, the battery charging/discharging measurement device <NUM> may be connected to the battery assembly provided in the units of the pack or module.

Thereafter, the battery charging/discharging measurement device <NUM> performs charging or discharging of the battery applying pulse current to the battery to measure the cell voltage of the battery.

According to an embodiment, the battery charging/discharging measurement device <NUM> is connected to anode (+) and cathode (-) leads of the battery assembly and applies the pulse current to the pack or module-form battery assembly, thereby measuring the cell voltage depending on battery charging or discharging.

Thereafter, the battery charging/discharging measurement device <NUM> may transmit a cell voltage measurement value depending on the battery charging or discharging to the impedance spectrum estimation device <NUM> to be described below.

<FIG> is a block diagram of a device for estimating an impedance spectrum according to an embodiment of the present invention.

Referring to <FIG>, the device <NUM> for estimating the impedance spectrum according to an embodiment of the present invention receives the impedance spectrum measurement value and the cell voltage measurement value for the pack or module-form battery assembly measured by the electrical impedance spectroscopy (EIS) device <NUM> and the battery charging/discharging measurement device <NUM> to estimate the cell-unit battery impedance spectrum.

When the device <NUM> for estimating an impedance spectrum of a battery cell is described in more detail for each hardware component, the impedance spectrum estimation device <NUM> may include a memory <NUM>, a processor <NUM>, a transceiving device <NUM>, an input interface device <NUM>, an output interface device <NUM>, and a storage device <NUM>.

According to an embodiment, respective components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> included in the impedance spectrum estimation device <NUM> are connected to each other by a bus <NUM> to communicate with each other.

Among the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of the impedance spectrum estimation device <NUM>, the memory <NUM> and the storage device <NUM> may be constituted by at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory <NUM> and the storage device <NUM> may be constituted by at least one of a read only memory (ROM) and a random access memory (RAM).

Among them, the memory <NUM> may include at least one instruction executed by the processor <NUM>.

According to an embodiment, at least one instruction may include a command of instructing acquiring an electrical impedance spectroscopy (EIS) measurement value of the battery assembly, a command of instructing modeling an equivalent circuit model (ECM) of the battery assembly based on the EIS measurement value, and determining initial parameter values for the equivalent circuit, a command of instructing deriving a first parameter value by converting at least one of the initial parameter values by using a predefined conversion constant, and calculating a first cell voltage value based on the first parameter value, a command of instructing acquiring a second cell voltage value measured by charging or discharging for the battery cell, a command of instructing comparing the first cell voltage value and the second cell voltage value, and correcting the conversion constant based on a comparison result, a command of instructing calculating a final parameter value based on the corrected conversion constant, and a command of instructing acquiring an EIS estimation value for the battery cell by applying the final parameter value to the equivalent circuit.

The processor <NUM> may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor that perform the methods according to embodiments of the present invention.

The processor <NUM> may execute at least one program command stored in the memory <NUM> as described above.

Hereinabove, the system for estimating the impedance spectrum of the battery according to an embodiment of the present invention is described. Hereinafter, a method for estimating the impedance spectrum of the battery cell depending on a processor operation of the impedance spectrum estimation device which is one of the components of the system for estimating the impedance spectrum of the battery will be described in more detail.

<FIG> is a flowchart for describing a method for measuring an impedance spectrum of a battery cell according to an embodiment of the present invention.

Referring to <FIG>, the processor <NUM> in the device <NUM> for estimating the impedance spectrum of the battery cell may acquire the impedance spectrum measurement value for the pack or module-unit battery assembly (S1000).

According to an embodiment, the processor <NUM> may receive the impedance spectrum value (EIS measurement value) measured by the pack or module-unit battery assembly from the electrical impedance spectroscopy (EIS) device <NUM>.

<FIG> is a Nyquist Plot graph showing an impedance measurement result for each frequency of a pack or module-unit battery assembly using an electrical impedance spectroscopy (EIS) device according to an embodiment of the present invention.

Referring to <FIG>, the impedance spectrum measurement value of the battery assembly (pack or module) acquired by the processor <NUM> may be represented as an impedance output value depending on a frequency. Here, Z' may be a real number value Z_re of the impedance and Z" may be an imaginary number value Z_im of the impedance.

Thereafter, the processor <NUM> may model the equivalent circuit of the battery assembly which is the pack or module unit (equivalent circuit model (ECM), S2000) based on the acquired EIS measurement value, and determine at least one initial parameter value of the modeled equivalent circuit (S3000). A method for modeling the equivalent circuit of the battery, and determining the initial parameter value of the modeled equivalent circuit will be described in more detail with reference to <FIG> below.

<FIG> is an equivalent circuit diagram of a battery assembly acquired based on the impedance measurement result in <FIG>.

Referring to <FIG>, the processor <NUM> may model the equivalent circuit of the battery to have the same impedance as the impedance spectrum measurement value of the battery assembly which is the pack or module unit.

According to an embodiment, amplitude and phase components representing output characteristics of the impedance spectrum may be expressed by at least one combination of a resistance, a capacitor, and an inductor. In other words, the pack or module-unit battery equivalent circuit model may be expressed as at least one parameter of resistances R0, R1, R2, R3, and R4, capacitors C1, C2, C3, and C4, an inductor L1, and a Constant Phase Element (CPE). Here, the CPE may be an impedance parameter that makes an intermediate impedance characteristic value of the capacitor and the resistance. For example, the battery equivalent circuit model (ECM) may be expressed as a sum of an impedance P1 depending on an electrolyte, an impedance P2 of the EIS device, an impedance P3 depending on of an SEI layer, an impedance P4 depending on electric charge movement between an electrode and an electrolytic solution interface, and a Warburg impedance coefficient P5. Here, the impedance P2 of the EIS device may include a resistance generated by a cable of a measurement device.

Thereafter, the processor <NUM> may determine the initial parameter value of the modeled equivalent circuit.

More specifically, the processor <NUM> may determine the initial parameter value of at least one of the resistance, the capacitor, the inductor, and the CPE in the equivalent circuit model of the battery as in [Table <NUM>] below based on the impedance spectrum measurement value of the battery which is the pack or module unit.

According to an embodiment, the processor <NUM> may infer values of variables based on the impedance measurement result graph for each frequency in <FIG> and the resulting equivalent circuit model in <FIG>. Thereafter, the processor <NUM> acquires the impedance measurement result graph for each frequency for the infer values of the variables and compares the acquired impedance measurement result value with the impedance measurement result graph for each frequency according to <FIG> to determine values of variables showing a similar pattern to the graph in <FIG> as the initial parameter value.

Referring back to <FIG>, the processor <NUM> divides the initial parameter value by a conversion constant n_Factor to acquire a battery cell-unit first parameter value as in [Table <NUM>] below (S4000).

Here, the conversion constant n-factor may be a constant for converting the initial parameter value acquired based on the pack or module-unit battery assembly into the batter cell unit. According to an embodiment, an initial value of the conversion factor n-Factor may be defined based on the number of battery cells included in the battery assembly (pack or module). For example, as in [Table <NUM>] below, some initial values R1, R2, and R3 of the conversion constants n-factor may be defined based on the number of battery cells (<NUM> battery cells) included in the module.

Meanwhile, as in [Table <NUM>] below, since the inductor L1 and the capacitors C1, C2, C3, and C4 slightly influence a change of a value of the impedance R (see [Equation <NUM>] below), the conversion constant n-factor may not be defined.

Further, the conversion constant may be corrected according to a comparison result of the first cell voltage value and the second cell voltage value in step S8000 to be described below. As a result, an initial value of the conversion constant may not be defined as an accurate value. However, as in [Table <NUM>] above, it is preferable that the conversion constant is defined as an approximate value for converting the assembly-unit parameter into the battery cell unit.

In an embodiment, the initial value of the conversion constant may be input by an administrator or defined as a prestored value corresponding to the number of battery cells.

Thereafter, the processor <NUM> may calculate an internal impedance function according to the time of the battery (S5000).

More specifically, the processor <NUM> may organize the equivalent circuit (ECM, see <FIG>) of the battery assembly (pack or module) into a function for the time by using a differential equation.

For example, when the method in which the processor <NUM> organizes RC parallel components P2, P3, and P4 in the equivalent circuit into the function for the time is described in more detail, the processor <NUM> may organize the RC parallel component into [Equation <NUM>] for current I by using the law of ohm (V = IR).

Thereafter, the processor <NUM> may express V(t) as E(t) based on [Equation <NUM>] extracted from [Equation <NUM>], and organize V(t) into [Equation <NUM>] for E(t). <MAT><MAT>.

Thereafter, the processor <NUM> organizes [Equation <NUM>] into an equation for the impedance R to obtain [Equation <NUM>]<MAT>.

As such, when the processor <NUM> also organizes an LR parallel component in the equivalent circuit model according to <FIG> like the RC parallel component by using the differential equation, the processor <NUM> may acquire the impedance function for the time from the equivalent circuit model as in [Equation <NUM>] below.

Thereafter, the processor <NUM> may apply the battery cell-unit first parameter value to the impedance function. In this case, W<NUM> as a Warburg impedance may be related to a diffusion speed of ions, and may be in inverse proportion to a square root of the frequency. As a result, the processor <NUM> may calculate an internal impedance of the cell-unit battery.

Thereafter, the processor <NUM> may calculate a fist cell voltage value by multiplying the internal impedance of the battery by a current value (S6000). In other words, the internal impedance of the battery may serve as an internal resistance value of the battery.

Further, the processor <NUM> may acquire a second cell voltage value measured by pulse current of the battery (S7000). Here, the second cell voltage value may be a cell voltage value measured by applying discharge pulse current to the pack or module-unit battery assembly from the battery charging/discharging measurement device <NUM>.

<FIG> is a graph of comparing a first cell voltage value calculated by using an impedance function to which a first parameter is applied and a second cell voltage value measured by applying discharge pulse current to a battery assembly in order to describe a method for estimating an impedance of a battery cell according to an experimental example of the present invention.

Referring to <FIG>, since the first cell voltage value is calculated by using a conversion constant defined based on the number of cells generally accommodated inside the battery assembly (pack or module), as a result of comparing the first cell voltage value and the second cell voltage value, there is a minute difference between the first cell voltage value and a second cell voltage value actually measured by applying the discharge pulse current.

Therefore, the processor <NUM> may correct the conversion constant n-factor so that the difference between the first cell voltage value and the second cell voltage value is minimized for each cell for calculation of a more precise impedance of the battery cell (S8000).

Here, the conversion constant n-factor may be a value divided to estimate at least one initial parameter constituting the equivalent circuit of the pack or module-unit battery assembly by a cell-unit value as described above. In other words, the processor <NUM> may acquire a more precise battery cell-unit final parameter value by correcting the conversion constant applied to the initial parameter of the equivalent circuit model by a value to minimize the difference between the first cell voltage value and the second cell voltage value (S9000).

For example, when the battery assembly (pack or module) is constituted by <NUM> cells, the processor <NUM> may correct the equivalent circuit parameter value for each battery cell as in [Table <NUM>] below.

<FIG> is a graph of comparing a third cell voltage value calculated by using an equivalent circuit model to which a final parameter value is applied and a second cell voltage value measured by applying discharge pulse current to a battery assembly in order to describe a method for estimating an impedance of a battery cell according to an experimental example of the present invention.

Referring to <FIG>, a third cell voltage may be a value calculated by multiplying the internal impedance acquired by applying the final parameter to the impedance function by the current value according to an embodiment of the present invention.

According to an embodiment, it may be identified that by a result of comparing the third cell voltage and the second cell voltage value measured by inputting actual discharge pulse current, the third cell voltage value calculated by using the final parameter value acquired by correcting the conversion constant is similar to the second cell voltage value measured by applying the actual discharge pulse current.

Referring back to <FIG>, the processor <NUM> individually applies the corrected battery cell-unit final parameter value to the equivalent circuit model to estimate the impedance spectrum for each battery cell (S10000).

According to an embodiment, the processor <NUM> may acquire the impedance spectrum estimation value for each battery cell by substituting the impedance spectrum measurement value acquired from the pack or module-unit battery assembly into the corrected equivalent circuit model to which the corrected final parameter value is applied. In this case, the corrected final parameter value may also be converted into the impedance spectrum value (Zre and Zim), and used.

Hereinabove, the device and the method for estimating the impedance spectrum of the battery according to the embodiment and the experimental example of the present invention, and the system including the same are described.

According to an embodiment and an experimental example of the present invention, a device and a method for estimating an impedance spectrum of a battery, and a system including the same can a device and a method for estimating an impedance spectrum of a high-efficiency and low-cost battery, and a system including the same, which estimate a cell-unit battery impedance spectrum value by acquiring measurement values from an Electrical Impedance Spectroscopy (EIS) device measuring an impedance spectrum value of a pack or module-unit battery assembly and a battery charging/discharging measurement device measuring a specific parameter value by charging or discharging by applying pulse current to the pack or module-unit battery assembly to facilitate reassembly and reduce cost by enabling non-destruction measurement without disassembling the battery into the cell unit.

The operation of the method according to the embodiment and the experimental example of the present invention may be implemented as a computer readable program or code in a computer readable recording medium. The computer readable recording medium includes all kinds of recording devices storing data which may be deciphered by a computer system. Further, the computer readable recording media may store and execute programs or codes which may be distributed in the computer system connected through a network and read by a computer in a distribution method.

Further, the computer readable recording medium may include a hardware device particularly configured to store and perform a program command, such as a ROM, a RAM, a flash memory, etc. An example of the program command includes a high-level language code executable by a computer by using an interpreter and the like, as well as a machine language code created by a compiler.

Some aspects of the present invention are described in a context of the device, but a description depending on the method corresponding thereto may also be represented, and here, the block or device corresponds to a method step or a feature of the method step. Similarly, the aspects described in the context of the method may also be represented as a feature of a corresponding block or item, or a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device such as a microprocessor, a programmable computer, or an electronic circuit, for example. In some embodiments, at least one of the most important method steps may be performed by such a device.

Claim 1:
A device (<NUM>) for estimating an impedance spectrum of a battery cell, the device comprising:
a memory (<NUM>); and
a processor (<NUM>) performing at least one command stored in the memory,
wherein the at least one command includes
a command of instructing acquiring an electrical impedance spectroscopy, EIS, measurement value of a battery assembly,
a command of instructing modeling an equivalent circuit model (ECM) of the battery assembly, and determining initial parameter values for the equivalent circuit, based on the EIS measurement value,
a command of instructing deriving a first parameter value by converting at least one of the initial parameter values by using a predefined conversion constant, and calculating a first cell voltage value based on the first parameter value,
a command of instructing acquiring a second cell voltage value measured by charging or discharging for the battery cell,
a command of instructing comparing the first cell voltage value and the second cell voltage value, and correcting the conversion constant based on a comparison result,
a command of instructing calculating a final parameter value based on the corrected conversion constant, and
a command of instructing acquiring an EIS estimation value for the battery cell by applying the final parameter value to the equivalent circuit.