METHOD AND DEVICE WITH CHARGING CONTROL

A processor-implemented method with charging control includes: estimating respective step degradation amounts in charging steps of a first charging interval for each of first candidate current patterns of charging a battery from a first state of charge (SOC) level to a second SOC level during the first charging interval; determining an interval degradation amount in the first charging interval for each of the first candidate current patterns, based on the estimated step degradation amounts; and selecting a first representative current pattern indicating a minimum degradation amount from among the first candidate current patterns, based on the determined interval degradation amounts.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 USC § 119(a) of Korean Patent Application No. 10-2021-0079309 filed on Jun. 18, 2021, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

The following description relates to a method and device with charging control.

2. Description of Related Art

A constant current-constant voltage (CC-CV) charging method may charge a battery until it reaches a preset low current value after charging the battery up to a certain voltage with a constant current. A multi-step charging method that may charge a battery in multiple steps while changing a charging current value. The multi-step charging method may minimize battery degradation in the case of fast charging. For the multi-step charging method, a battery state may be estimated, and the battery state may be estimated using various methods. For example, the battery state may be estimated using a battery simulation model, for example, an electric circuit model or an electrochemical model. The electric circuit model may be a circuit model including resistors and capacitors representing a voltage value that varies as a battery is charged or discharged. The electrochemical model may be a model that models internal physical phenomena of a battery, such as, for example, a battery ion concentration, a potential, and the like.

SUMMARY

In one general aspect, a processor-implemented method with charging control includes: estimating respective step degradation amounts in charging steps of a first charging interval for each of first candidate current patterns of charging a battery from a first state of charge (SOC) level to a second SOC level during the first charging interval; determining an interval degradation amount in the first charging interval for each of the first candidate current patterns, based on the estimated step degradation amounts; and selecting a first representative current pattern indicating a minimum degradation amount from among the first candidate current patterns, based on the determined interval degradation amounts.

The first candidate current patterns may correspond to different combinations of charging current values respectively for the charging steps of the first charging interval.

The estimating of the step degradation amounts may include estimating the step degradation amounts in the charging steps for each of the first candidate current patterns using a simulation model of the battery, and the determining of the interval degradation amounts may include determining an interval degradation amount of each of the first candidate current patterns by accumulating the step degradation amounts of each of the first candidate current patterns in the first charging interval.

The first charging interval may include a first charging step and a second charging step, and the first candidate current patterns may include a first pattern of applying a first current value during the first charging step and applying a second current value during the second charging step.

The estimating of the step degradation amounts may include: estimating a first step degradation amount of the first pattern based on the first current value; and estimating a second step degradation amount of the first pattern based on the second current value, and the determining of the interval degradation amounts may include determining a first interval degradation amount of the first pattern by accumulating the first step degradation amount and the second degradation amount.

The simulation model may be an electrochemical model.

The method may include removing data associated with remaining current patterns excluding the first representative current pattern from among the first candidate current patterns.

The method may include selecting a second representative current pattern of charging the battery from the second SOC level to a third SOC level during a second charging interval, based on the first representative current pattern.

A battery state value that is based on the first representative current pattern may be used to determine second candidate current patterns for the second charging interval and determine an interval degradation amount of each of the second candidate current patterns.

In the determining of the second candidate current patterns, remaining first current patterns excluding the first representative current pattern from among the first candidate current patterns may be excluded.

The step degradation amounts in the charging steps for each of the first candidate current patterns may be estimated using a simulation model of the battery, and the simulation model may be updated based on a degradation state of the battery.

The method may include: determining a reference dataset based on the first representative current pattern; and controlling charging in each charging step for the battery based on the determined reference dataset.

The controlling of the charging may include: estimating an internal state of the battery using a simulation model of the battery; and controlling a charging current based on the reference dataset and the internal state.

The method may include updating the reference dataset based on a degradation state of the battery.

In another general aspect, one or more embodiments include a non-transitory computer-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform any one, any combination, or all operations and methods described herein.

In another general aspect, a device with charging control includes: a processor configured to: estimate respective step degradation amounts in charging steps of a first charging interval for each of first candidate current patterns of charging a battery from a first state of charge (SOC) level to a second SOC level during the first charging interval; determine an interval degradation amount in the first charging interval for each of the first candidate current patterns, based on the estimated step degradation amounts; and select a first representative current pattern indicating a minimum degradation amount from among the first candidate current patterns, based on the determined interval degradation amounts.

The first candidate current patterns may correspond to different combinations of charging current values respectively for the charging steps of the first charging interval.

The processor may be configured to: for the estimating of the step degradation amounts, estimate the step degradation amounts in the charging steps for each of the first candidate current patterns, using a simulation model of the battery; and for the determining of the interval degradation amounts, determine the interval degradation amount of each of the first candidate current patterns by accumulating the step degradation amounts of each of the first candidate current patterns in the first charging interval.

The processor may be configured to select a second representative current pattern of charging the battery from the second SOC level to a third SOC level during a second charging interval, based on the first representative current pattern, and a battery state value that is based on the first representative current pattern may be used to determine second candidate current patterns for the second charging interval and determine an interval degradation amount of each of the second candidate current patterns.

In the determining of the second candidate current patterns, remaining current patterns excluding the first representative current pattern from among the first candidate current patterns may be excluded.

The device may include a memory storing instructions that, when executed by the processor, configure the processor to perform the estimating of the respective step degradation amounts, the determining of the interval degradation amount, and the selecting of the first representative current pattern.

In another general aspect, a processor-implemented method with charging control includes: estimating, for charging a battery from a first state of charge (SOC) to a second SOC over a first charging interval, battery degradation amounts each corresponding to a respective candidate current pattern; determining, as a current pattern of the first interval, one of the candidate current patterns corresponding to a minimum of the battery degradation amounts; and determining, for charging the battery from the first SOC to a third SOC over a plurality of charging intervals including the first interval, a final current pattern to include the determined current pattern of the first interval.

The determining of the final current pattern may include estimating a current pattern of a subsequent charging interval based on the determined current pattern of the first interval.

The determining of the current pattern of the first interval may include deleting the candidate current patterns from a memory except for the determined current pattern of the first interval.

Each of the current patterns for the first charging interval may be a pattern of charging the battery based on two or more charging currents over the first charging interval.

The first charging interval may include a plurality of charging steps, and two or more of the candidate current patterns may include different charging currents for one or more of the charging steps.

The method may include charging the battery based on the final charging current pattern.

DETAILED DESCRIPTION

The terminology used herein is for describing various examples only and is not to be used to limit the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term “and/or” includes any one and any combination of any two or more of the associated listed items. As used herein, the terms “comprises,” “includes,” and “has” specify the presence of stated integers, steps, features, numbers, operations, members, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other integers, steps, features, numbers, operations, members, elements, and/or combinations thereof. The use of the term “may” herein with respect to an example or embodiment (for example, as to what an example or embodiment may include or implement) means that at least one example or embodiment exists where such a feature is included or implemented, while all examples are not limited thereto.

Throughout the specification, when an element, such as a layer, region, or substrate, is described as being “on,” “connected to,” or “coupled to” the other element, it may be directly “on,” “connected to,” or “coupled to” the other component, or there may be one or more other elements intervening therebetween. In contrast, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there can be no other elements intervening therebetween. Likewise, expressions, for example, “between” and “immediately between” and “adjacent to” and “immediately adjacent to” may also be construed as described in the foregoing.

Also, in the description of example embodiments, detailed description of structures or functions that are thereby known after an understanding of the disclosure of the present application will be omitted when it is deemed that such description will cause ambiguous interpretation of the example embodiments. Hereinafter, examples will be described in detail with reference to the accompanying drawings, and like reference numerals in the drawings refer to like elements throughout.

FIG.1illustrates an example of a charging control device and an example of a battery. Referring toFIG.1, a charging control device110may control charging of a battery120. The charging control device110may generate a reference dataset for charging the battery120and/or control the charging of the battery120based on the reference dataset. In a non-limiting example, the charging control device110includes the battery120.

The charging control device110may use a multi-step charging method. The reference dataset may include control parameters for multi-step charging. For example, the reference dataset may include a charging limit condition and a charging current value for each charging step and may be provided in the form of a lookup table (LUT). The charging limit condition may include conditions associated with a negative electrode potential, a cell voltage, a state of charge (SOC), a positive electrode potential, a positive electrode lithium concentration, a negative electrode lithium concentration, and/or the like. For example, in one charging step, the battery120may be charged with a charging current value of the charging step. When the charging limit condition of the charging step is satisfied, the battery120may be charged with a charging current value of a subsequent charging step.

The charging control device110may derive a charging current sequence that minimizes degradation of the battery120, while satisfying a given charging target, for example, to charge the battery120from an SOC level of 0% to 50% for ten minutes, to charge the battery120from an SOC level of 0% to 80% for 30 minutes, and the like. The charging control device110may detect a pattern indicating a minimum degradation amount among various current patterns that may be derived by combining charging current values for each step. The charging control device110may calculate respective step degradation amounts in charging steps for each current pattern, accumulate the step degradation amounts of each current pattern, and estimate a degradation effect of each current pattern.

The charging control device110may estimate a state (e.g., an SOC, an internal state, a degradation state, etc.) of the battery120in various ways. The charging control device110may use a simulation model, such as, for example, an electrochemical thermal (ECT) model. Although a non-limiting example of controlling charging using the ECT model will be described hereinafter, this is provided merely as an example. For example, other methods such as a current integration method and a method using another simulation model such as an electric circuit model may be used.

The ECT model may be a model that models an internal physical phenomenon of a battery, for example, a battery ion concentration, a potential, and the like. The ECT model may simulate an internal state of the battery120using various ECT parameters and governing equations. For example, such parameters of the ECT model may indicate a shape (e.g., a thickness, a radius, etc.), an open circuit potential (OCP), and physical properties (e.g., an electrical conductivity, an ionic conductivity, a diffusion coefficient, etc.). The governing equations may include an electrochemical reaction occurring between an electrode and an interface of an electrolyte based on these parameters, a physical conservation equation associated with the electrode, a concentration of the electrolyte, and conservation of electrical charges. The charging control device110may estimate a state and/or a degradation amount of the battery120based on operation data (e.g., a voltage, a current, a temperature, etc.) and the ECT model of the battery120.

As the battery120continues operating, a cell of the battery120may be degraded and a state of the cell may thereby change. Such a change in the cell state may reduce the accuracy in SOC estimation performed using the ECT model. The charging control device110may update the ECT model based on a degradation state of the battery120to maintain or increase the accuracy in the estimation. The updating of the ECT model may include updating the parameters of the ECT model. The charging control device110may update the reference dataset using the updated ECT model to maintain a charging current pattern to be in an optimal state.

FIG.2illustrates an example of multi-step charging. Referring toFIG.2, a charging profile200may include a plurality of charging points201through222. The charging points201through222may indicate specific SOC levels at specific times. For example, the charging point211may indicate an SOC level SOC1at a time t3, and the charging point212may indicate an SOC level SOC2at the time t3. Through battery charging, an SOC of a battery may reach the charging points201through222.

A path to reach each of the charging points201through222may vary depending on a charging current value. For example, a path from a starting point to the charging point211may include a first path through the charging points201and202and a second path through the charging points203and204. When a current value increases, a slope of a path, that is, an SOC change amount based on a time (e.g., an SOC rate of change), may increase. For example, a charging current value of a path from the starting point to the charging point203may be greater than a charging current value of a path from the starting point to the charging point201. Each path may form a current pattern based on a sequence of charging current values.

A charging control device may search for an optimal path based on a charging step corresponding to a unit time. A charging step may be divided by an interval between times adjacent to each other, for example, t0and t1. The charging control device may set a charging current value for each charging step as a unit. For example, the charging control device may determine a charging path by setting a first charging current value for a first charging step and setting a second charging current value for a second charging step. In this example, the first charging current value and the second charging current value may be the same value or different values.

The charging control device may determine an optimal path for each charging interval. One or more charging steps may constitute a single charging interval. In other words, a charging interval may include one or more charging steps. In the example ofFIG.2, one charging interval may include three charging steps. However, examples are not limited to the example ofFIG.2. For example, one charging interval may include two charging steps or four or more charging steps. In addition, all charging intervals may include the same number of charging steps, or at least a portion of the charging intervals may include different numbers of charging steps. For example, the charging control device may set first three charging steps t0through t3as an initial charging interval, and set an optimal path for each of the final charging points211and212of the initial charging interval. Subsequently, the charging control device may set a charging interval for each charging steps (e.g., t3-t4, t4-t5, t5-t6, . . . ) and determine an optimal path for each charging interval. For another example, the charging control device may set three charging steps (e.g., t0-t3, t4-t6, t7-t9, . . . ) as a charging interval.

The charging control device may derive a final path to a final target point, for example, 80% charging for 30 minutes, while partially searching for an optimal path for each charging interval. The charging control device may estimate an SOC and a charging path while adjusting a simulation condition (for example, a charging current value and a charging time or charging step) of a battery simulation model. In addition, the charging control device may determine a degradation amount of each path based on a battery state using the simulation model. The charging control device may search for an optimal path based on the degradation amount.

The charging control device may determine various current patterns based on a charging current value, and determine, to be a representative current pattern (or an optimal current pattern) at a charging point, a current pattern that indicates a minimum degradation amount from among current patterns reaching the charging point. For example, when a first current pattern passing through the charging points201and202and a second current pattern passing through the charging points203and204are present for the charging point211, the current pattern among the first current pattern and the second current pattern that indicates a lower degradation amount between the first current pattern and the second current pattern may be determined to be a representative current pattern for the charging point211. A representative current pattern for the charging point212may also be determined in a similar way as the foregoing.

When the representative current pattern for each charging point is determined, the charging control device may remove data associate with remaining current patterns excluding the representative current pattern. For example, the charging control device may delete the data associated with the remaining current patterns from a memory. To determine current patterns for subsequent target points, for example, the charging points221and222, the charging control device may calculate a degradation amount from the previous charging points211and212based on representative current patterns of the previous charging points211and212. The number of cases according to different current patterns of the previous charging points211and212(e.g., the remaining current patterns that are not the representative current patterns) may not be used to determine the current patterns for the subsequent charging points221and222. Accordingly, the charging control device of one or more embodiments may reduce the amount of calculation and improve memory efficiency.

FIG.3illustrates an example of deriving candidate current patterns by combining charging currents for each charging step. Referring toFIG.3, a plurality of charging points311,312, and313may be defined based on a time t1by referring to a charging profile310. A period between a time t0and a time t1may correspond to a first charging step. For example, each charging step may correspond to an amount of time (for example, 30 seconds, one minute, or three minutes). The charging point311may indicate a state in which an SOC level of a battery reaches SOC, at the time t1when a first charging current I1is applied to the battery during the first charging step between t0and t1. The charging point312may indicate a state in which the SOC level of the battery reaches SOC2at the time t1when a second charging current I2is applied to the battery during the first charging step between t0and t1. The charging point313may indicate a state in which the SOC level of the battery reaches SOC3at the time t1when a third charging current I3is applied to the battery during the first charging step between t0and t1. As a current value increases, a slope of a path (that is, an SOC change amount based on a time) may increase. For example, when I2is greater than I1by a factor of 2 times and I3is greater than I1by a factor of 3 times, SOC2may be greater than SOC1by a factor of 2 times and SOC3may be greater than SOC1by a factor of 3 times.

Referring to the charging profile320, a plurality of charging points may be defined at a time t2based on I1through I3. For example, a charging point321may be determined by applying I2to the charging point311or applying I1to the charging point312, and a charging point322may be determined by applying I2to the charging point312or applying I1to the charging point313. As described above, charging points may be determined for each charging step based on charging current values. For example, a charging current may have current values at intervals of 0.1 C from 1 C to 1.8 C (however, examples are not limited thereto, and the current values may be measured in any unit of current such as amperes A). In this example, nine charging points may be defined at the time ti, dissimilar to the foregoing example.

A charging control device may determine various charging paths that pass through charging points (for example, the charging points311through322) while changing a charging current value for each charging step. These charging paths may respectively correspond to current patterns. The current patterns may correspond to different combinations of charging current values for charging steps of a charging interval. For example, charging paths to the charging point321may correspond to current patterns [I1I2] and [I2I1], and charging paths to the charging point322may correspond to current patterns [I3I1], [I2I2], and [I1I3]. The charging control device may determine a degradation amount of each current pattern, and determine an optimal current pattern based on the determined degradation amount. Herein, a candidate for selecting an optimal current pattern may be referred to as a candidate current pattern, and the optimal current pattern may be referred to as a representative current pattern.

FIGS.4A and4Billustrate examples of determining a step degradation amount and an interval degradation amount.FIG.4Aillustrates an example of an operation in an interval from a time t0to a time t2. A charging control device may determine step degradation amounts of each candidate current pattern. A step degradation amount described herein may indicate an amount of degradation represented in a unit of a charging step. In addition, an interval degradation amount described herein may indicate an amount of degradation represented in a unit of a charging interval. The charging control device may determine the step degradation amounts of each candidate current pattern based on an internal state of a battery that is estimated using a simulation model. For example, as illustrated in a charging profile401, the charging control device may estimate step degradation amounts in a first charging step from t0to t1from respective applications of I1, I2, and I3for charging points of the time t1, and estimate step degradation amounts in a second charging step from t1to t2from respective applications of I1, I2, and I3for charging points of the time t2.

The charging control device may determine an interval degradation amount of each candidate current pattern by accumulating, along a charging interval, the step degradation amounts of each candidate current pattern, and determine a representative current pattern for each charging point based on the interval degradation amount of each candidate current pattern. For example, as illustrated inFIG.4A, the first charging step from t0to t1and the second charging step from t1to t2may constitute an initial charging interval, and the charging control device may determine representative current patterns for charging points of t2based on an interval degradation amount of each candidate current pattern in the initial charging interval. Although the following description will focus on the non-limiting example in which two charging steps constitute an initial charging interval, three or more charging steps may constitute one charging interval.

Charging paths leading to a charging point410may include a first current pattern [I1I3], a second current pattern [I2I2], and a third current pattern [I3I1]. The charging control device may determine an interval degradation amount of the first current pattern by accumulating a step degradation amount based on application of I1during the first charging step from t0to t1and a step degradation amount based on application of I3during the second charging step from t1to t2. Similarly, the charging control device may determine an interval degradation amount of the second current pattern and an interval degradation amount of the third current pattern. The determined interval degradation amounts may be represented as Jt1,SOC1+Lt1,SOC1,I3, Jt1,SOC2+Lt1,SOC2,I2, and Jt1,SOC3+Lt1,SOC3,I1. Jt1,SOC1, Jt1,SOC2, and Jt1,SOC3may represent the step degradation amounts in the first charging step from t0to t1. Lt1,SOC1,I3, Lt1,SOC2,I2, and Lt1,SOC3,I1may represent the step degradation amounts in the second charging step from t1to t2. For example, Jt1,SOC1may represent a step degradation amount as the battery at an initial point reaches a charging point (t1, SOC1), and Lt1,SOC1,I3may represent a step degradation amount as a charging current value I3is applied to the battery at the charging point (t1, SOC1). When a starting point is different even with the same charging current value, different step degradation amounts may be exhibited, and L may thus include information about the starting point.

In one example, the charging control device may derive a degradation amount based on Equation 1 below, for example.

Based on Equation 1, a side reaction current based on an internal state of a battery may be calculated. A side reaction may be considered as corresponding to degradation of the battery, and thus a degradation amount may be derived from the side reaction current that indicates an amount of the side reaction occurring per unit time. In Equation 1 above, jsideLidenotes an anode side reaction current. ηsidedenotes an anode overpotential with respect to a side reaction. R denotes an ideal gas constant, and T denotes a temperature. αa,sideand αc,sidedenote charge transfer coefficients with respect to reduction-oxidation. nsideF denotes a quantity of electrical charges of a side reaction, and asdenotes an active surface area of an anode. i0,sidedenotes an exchange current density with respect to an anode side reaction. i0,sidemay be represented as Equation 2 below, for example.

In Equation 2 above, cs,surfdenotes a lithium concentration of an electrode surface. cEC,Rsdenotes an electrolyte concentration of the electrode surface, and ksidedenotes a kinetic rate constant with respect to a side reaction. A remaining portion excluding cs,surfin Equation 2 may be represented by keff, which may correspond to a degradation rate coefficient. In a case of calculating and comparing degradation amounts for respective charging control conditions in a certain degradation state, keffmay be assumed to be the same and thus be disregarded. When keffis derived, a degradation amount may be calculated inversely from Equation 1. The charging control device may estimate an internal state of a battery through a simulation model (for example, an ECT model) and derive a side reaction current from the internal state by applying a value of the estimated internal state to Equation 1. For example, parameter values such as ηside, T, and cs,surfmay be determined through the simulation model. The side reaction current may correspond to each step degradation amount.

The charging control device may determine a candidate current pattern indicating a minimum interval degradation amount to be a representative current pattern for the charging point410. A degradation amount at the charging point410based on the representative current pattern may be represented as min[(Jt1,SOC1+Lt1,SOC1,I3), (Jt1,SOC2+Lt1,SOC2,I2), (Jt1,SOC3+Lt1,SOC3,I1)]. The charging control device may determine a representative current pattern for another charging point of t2such as a charging point420in a similar way described above.

FIG.4Billustrates an example of an operation after t2. When representative current patterns of respective charging points of a certain charging interval are determined, remaining candidate current patterns excluding the representative current patterns may be excluded to determine a current pattern for a subsequent charging interval. The remaining candidate current patterns may be deleted from a memory. For example, candidate current patterns of charging points430of txmay be determined based on representative current patterns of the charging points410and420. In this example, remaining candidate current patterns of the charging points410and420may be excluded. In this example, x may have various values. When an interval degradation amount is calculated for each charging step and a representative current pattern is derived for each charging step, x may be 3 (x=3). When a degradation amount is calculated for every two charging steps and a representative current pattern is derived for every two charging steps, x may be 4 (x=4).

The charging control device may derive a final current pattern that reaches a final target point (for example, charging a battery from an SOC level of 0% to 50% for 10 minutes, charging a battery from an SOC level of 0% to 80% for 30 minutes, and the like) while searching for, or determining, a representative current pattern for each charging interval. The charging control device may determine a reference dataset based on the final current pattern. The reference dataset may include a charging limit condition and a charging current value for each charging step. The charging control device may charge the battery based on the reference dataset, and update and use the reference dataset in a situation such as when the battery is degraded.

FIG.5illustrates an example of controlling a charging current based on a reference dataset. Referring toFIG.5, a charging control device may control charging in each charging step of a battery based on a reference dataset510. For example, the charging control device may adjust a charging current in each charging step based on the reference dataset510. A charging profile520may represent a change in charging current based on a lapse of a charging time. The charging control device may charge the battery with a charging current value matched to each charging step based on the reference dataset510. When a charging limit condition for each charging step is satisfied, the battery may be charged with a charging current value matched to a subsequent charging step.

When charging is repeated, the battery may be degraded. In addition, fast charging may accelerate such degradation. Charging or fast charging based on the reference dataset510of one or more embodiments may greatly reduce a rate at which degradation progresses, compared to charging or fast charging based on a typical current pattern. Such a rate difference may increase further as the number of repetitions of a charging and discharging cycle increases.

FIG.6illustrates an example of deriving a reference dataset while increasing a charging step. Operations601through611to be described hereinafter with reference toFIG.6may be performed sequentially or non-sequentially. For example, the sequence of operations601through611may be changed and/or at least two of operations601through611may be performed in parallel.

Referring toFIG.6, in operation601, a charging control device may apply a current of preset values to a battery at an initial SOC during a first charging step from 0 to Δt. The charging control device may estimate a result of applying the current using a simulation model of the battery, rather than actually applying a current to the battery.

In operation602, the charging control device may calculate a cumulative degradation amount for each SOC. In operation603, the charging control device may store a battery state value of the battery and the cumulative degradation amount for each SOC. Operations602and603may be performed at Δt after the first charging step from 0 to Δt elapses. Each SOC may correspond to each charging point of Δt, and a range of SOCs may be dependent on a range of charging current values. For example, Δt may be one minute, and a charging current may have current values from 1 C through 1.8 C at intervals of 0.1 C therebetween. In this example, nine charging points may be defined for a time t1. By applying each charging current to an ECT model, a state of the battery may be estimated through the ECT model, and the battery state value may indicate the state of the battery. The charging control device may store battery state values for respective SOCs, and then use the stored battery state values to derive a subsequent current pattern. Thus, the charging control device of one or more embodiments may maintain continuity of the battery and improve accuracy of data associated with, for example, a degradation amount and the like.

In operation604, N may be initialized to 2 (N=2). In operation605, the charging control device may apply the current of preset values to the battery at each SOC during an Nth charging step from (N−1)Δt to NΔt. Currently, N is 2 (N=2), and thus the Nth charging step from (N−1)Δt to NΔt may be a second charging step from Δt to 2Δt. As described above, the charging control device may use the simulation model.

In operation606, the charging control device may calculate a cumulative degradation amount of each candidate current pattern. In operation607, the charging control device may store a battery state value corresponding to a representative current pattern and a cumulative degradation amount of the representative current pattern. Operations606and607may be performed at 2Δt after the second charging step from Δt to 2Δt elapses. The charging control device may calculate a cumulative degradation amount of each candidate current pattern using a battery state value at each SOC that is stored in operation603, and select a representative current pattern indicating a minimum degradation amount from among candidate current patterns. In operation608, the charging control device may delete information of remaining current patterns excluding the representative current pattern from the candidate current patterns.

In operation609, the charging control device may compare N and NF. NFdenotes a total number of charging steps. When N is less than NF, the charging control device may increase N by 1 in operation610, and perform operation605. When N is greater than NF, the charging control device may determine a reference dataset in operation611. The charging control device may control charging in each charging step of the battery based on the reference dataset. As illustrated inFIG.6, the charging control device may calculate an interval degradation amount while increasing N by 1. In this example, a charging interval may include one charging step. However, when a charging interval includes a plurality of charging steps, a cumulative degradation amount and a representative current pattern may be derived in a unit of two or more charging steps.

FIG.7illustrates an example of charging a battery by updating a battery degradation state and a reference dataset. Operations701through710to be described hereinafter with reference toFIG.7may be performed sequentially or non-sequentially. For example, the sequence of operations701through710may be changed and/or at least two of operations701through710may be performed in parallel.

Referring toFIG.7, in operation701, a charging control device may enter a charging mode. For example, when a battery is connected to a wired or wireless charger, the charging control device may perform operation701. In operation702, the charging control device may determine a reference dataset. When the reference dataset that is generated previously is stored in a memory, the charging control device may load the reference dataset from the memory. The reference dataset may be generated through operations described above with reference toFIGS.1through7. In operation703, the charging control device may charge the battery based on the reference dataset. For example, the charging control device may control a charging current based on a charging limit condition.

In operation704, the charging control device may estimate an internal state of the battery, and charge the battery in operation703based on the internal state of the battery. The charging control device may estimate the internal state of the battery using a simulation model, and control the charging current based on the reference dataset and the internal state. For example, the charging control device may estimate the internal state of the battery using an ECT model, and apply a charging current matched to each charging step to the battery while determining whether the charging limit condition of each charging step is satisfied or not.

In operation705, the charging control device may update a degradation state of the battery. For example, the charging control device may update the simulation model based on operation data of the battery. The charging control device may define a degradation parameter indicating the degradation state of the battery based on an ECT parameter of the ECT model, and update the degradation parameter such that the degradation state of the battery is applied thereto. The degradation parameter may include, for example, a surface resistance of an anode, a capacity of a cathode active material, an electrode balance shift of the anode and the cathode, and the like. The degradation parameter may vary according to a degradation model. The charging control device may estimate the internal state based on the degradation state of the battery in operation704. For example, the charging control device may apply the degradation state of the battery to the ECT parameter. The charging control device may update the reference dataset based on the degradation state.

In operation707, the charging control device may determine whether a reference dataset update condition is satisfied or not. The update condition may include, for example, a condition that a state of health (SOH) decreases to be less than a threshold value, a condition that a degradation amount exceeds a threshold value, and a condition that a device usage time exceeds a threshold value. Alternatively, the reference dataset may be updated each time the degradation parameter is updated. When the update condition is satisfied, the charging control device may derive a new reference dataset in operation709The charging control device may derive the new reference dataset through operations described above with reference toFIGS.1through7. The charging control device may then update the reference dataset to the new reference dataset in operation710. When the update condition is not satisfied, the charging control device may maintain the reference dataset in operation708. The charging control device may then determine to use the reference dataset or the new reference dataset in operation702.

FIG.8illustrates an example of a charging control device. Referring toFIG.8, a charging control device800may include a processor810(e.g., one or more processors) and a memory820(e.g., one or more memories). The memory820may be connected to the processor810, and store therein instructions executable by the processor810and data to be processed by the processor810or data processed by the processor810. The memory820may include a non-transitory computer-readable medium, for example, a high-speed random-access memory (RAM) and/or a nonvolatile computer-readable storage medium (e.g., one or more disk storage devices, flash memory devices, or other nonvolatile solid-state memory devices).

The processor810may execute instructions for performing any or all of the operations described herein with reference toFIGS.1through7and9through12. For example, the processor810may estimate step degradation amounts in respective charging steps of a first charging interval for each of first candidate current patterns of charging a battery from a first SOC level to a second SOC level during the first charging interval, determine an interval degradation amount in the first charging interval for each of the first candidate current patterns based on the estimated step degradation amounts, and select a first representative current pattern indicating a minimum degradation amount from among the first candidate current patterns based on the determined interval degradation. For a more detailed description of the charging control device800, reference may be made to what is described herein with reference toFIGS.1through7and9through12.

FIG.9illustrates an example of an electronic device including a charging control device. Referring toFIG.9, an electronic device900may include a battery910and a charging control device920. The charging control device920may be provided as at least a portion of a battery management system (BMS) of the electronic device900. The battery910may provide power to the electronic device900, and the charging control device900may generate a reference dataset for charging the battery910and/or control the charging of the battery910based on the reference dataset.

The charging control device920may generate the reference dataset in an on-device manner. Alternatively, the charging control device920may generate the reference dataset using a server. For example, the charging control device920may generate the reference dataset using a resource of the server, or receive the reference dataset generated by the server. The charging control device920may store and/or synchronize the reference dataset, a simulation model, and the like in the server, and use the data and/or model in the server as needed. For a more detailed description of the electronic device900, reference may be made to what is described herein with reference toFIGS.1through8and10through12.

FIG.10illustrates an example of a battery management server including a charging control device. Referring toFIG.10, a charging control device1011may be included in a battery management server1010. The charging control device1011may generate a reference dataset based on information associated with a battery1021, and an electronic device1020may control the battery1021by receiving the reference dataset. In this case, the electronic device1020may include a separate BMS configured to control the battery1021. Between the charging control device1011and the battery1021, a communicator and the BMS may perform needed functions. The electronic device1020may be run by power provided by the battery1021. For a more detailed description of the battery management server1010and the electronic device1020, reference may be made to what is described herein with reference toFIGS.1through9,11, and12.

FIG.11illustrates an example of an electronic device including various components. Referring toFIG.11, an electronic device1100may include a processor1110(e.g., one or more processors), a memory1120(e.g., one or more memories), a camera1130, a storage device1140, an input device1150, an output device1160, a network interface1170, and a battery1180, which may communicate with one another through a communication bus1190. For example, the electronic device1100may be provided as at least a portion of a mobile device (e.g., a mobile phone, a smartphone, a personal digital assistant (PDA), a netbook, a tablet computer, a laptop computer, etc.), a wearable device (e.g., a smart watch, a smart band, smart eyeglasses, etc.), a computing device (e.g., a desktop, a server, etc.), a home appliance (e.g., a television (TV), a smart TV, a refrigerator, etc.), a security device (e.g., a door lock, etc.), and a vehicle (e.g., an autonomous vehicle, a smart vehicle, etc.). The electronic device1100may structurally and/or functionally include the charging control device110ofFIG.1, the charging control device800ofFIG.8, the electronic device900ofFIG.9, the battery management server1010ofFIG.10, and/or the electronic device1020ofFIG.10.

The processor1110may execute functions and instructions in the electronic device1100. The processor1110may process instructions stored in the memory1120or the storage device1140. The processor1110may perform the operations described herein with reference toFIGS.1through10, and12. The memory1120may store data for controlling charging of the battery1180. The memory1120may include a computer-readable storage medium or a computer-readable storage device. The memory1120may store instructions to be executed by the processor1110, and related information while software and/or application is being executed by the processor1100.

The camera1130may capture an image and/or a video. The camera1130may be a three-dimensional (3D) camera including depth information of objects. The storage device1140may include a computer-readable storage medium or a computer-readable storage device. The storage device1140may store a greater amount of information than the memory1120and store the information for a long period of time. The storage device1140may include, for example, a magnetic hard disk, an optical disc, a flash memory, a floppy disc, or a nonvolatile memory of other types known in relevant technical fields.

The input device1150may receive an input from a user through a traditional input method using a keyboard and a mouse or through a new input method using a touch input, a voice input, and an image input. The input device1150may include, for example, a keyboard, a mouse, a touchscreen, a microphone, or any other device that may detect an input from a user and transfer the detected input to the electronic device1100. The output device1160may provide an output of the electronic device1100to a user through a visual, auditory, or tactile channel. The output device1160may include, for example, a display, a touchscreen, a speaker, a vibration generator, or any other device that may provide an output of the electronic device1110to a user. The network interface1170may communicate with an external device through a wired or wireless network. The battery1180may be a secondary battery such as a lithium-ion battery. For a more detailed description of the electronic device1100, reference may be made to what is described herein with reference toFIGS.1through10, and12.

FIG.12illustrates an example of a charging control method. Operations1210through1230to be described hereinafter with reference toFIG.12may be performed sequentially or non-sequentially. For example, the sequence of operations1210through1230may be changed and/or at least two of operations1210through1230may be performed in parallel.

Referring toFIG.12, in operation1210, a charging control device may estimate step degradation amounts in respective charging steps of a first charging interval for each of first candidate current patterns of charging a battery from a first SOC level to a second SOC level during the first charging interval. The first candidate current patterns may correspond to different combinations of charging current values for the charging steps of the first charging interval.

In operation1220, the charging control device may determine an interval degradation amount in the first charging interval for each of the first candidate current patterns based on the step degradation amounts. Operation1210may include estimating the step degradation amounts in the charging steps for each of the first candidate current patterns using a simulation model of the battery. Operation1220may include determining the interval degradation amount of each of the first candidate current patterns by accumulating the step degradation amounts of each of the first candidate current patterns along the first charging interval. The simulation model may be, for example, an ECT model.

For example, the first charging interval may include a first charging step and a second charging step, and the first candidate current patterns may include a first pattern of applying a first current value during the first charging step and applying a second current value during the second charging step. In this example, operation1210may include estimating a first step degradation amount of the first pattern based on the first current value, and estimating a second step degradation amount of the first pattern based on the second current value. In this example, operation1220may include determining a first interval degradation amount of the first pattern by accumulating the first step degradation amount and the second step degradation amount.

In operation1230, the charging control device may select a first representative current pattern indicating a minimum degradation amount from among the first candidate current patterns based on the interval degradation amount. The charging control device may remove data associated with remaining current patterns excluding the first representative current pattern from the first candidate current patterns.

The charging control device may select a second representative current pattern of charging the battery from the second SOC level to a third SOC level during a second charging interval based on the first representative current pattern. The charging control device may use a state value of the battery that is based on the first representative current pattern to determine second candidate current patterns in the second charging interval and determine an interval degradation amount of each of the second candidate current patterns. When determining the second candidate current patterns, the charging control device may exclude the remaining current patterns excluding the first representative current pattern from the first candidate current patterns.

The charging control device may estimate the step degradation amounts in the charging steps for each of the first candidate current patterns using the simulation model of the battery, and update the simulation model based on a degradation state of the battery. The charging control device may determine a reference dataset based on the first representative current pattern, and control charging of the battery in each of the charging steps based on the reference dataset. The charging control device may estimate an internal state of the battery using the simulation model, and control a charging current based on the reference dataset and the internal state. The charging control device may update the simulation model and the reference dataset based on the degradation state of the battery. For a more detailed description of the charging control method, reference may be made to what is described above with reference toFIGS.1through12.