Battery management apparatus and operating method of the same

Abstract

A battery management device according to one embodiment disclosed in this document may include an information acquisition unit that acquires information regarding two different phases of a battery active material and a controller that calculates information related to crosstalk between the two different phases based on the information regarding the two different phases of the battery active material.

Description

Technology Field

[0001] The embodiments disclosed in this document relate to a battery management device and a method of operating the same. Background Technology

[0002] Recently, active research and development on secondary batteries has been underway. Here, secondary batteries refer to rechargeable batteries, encompassing conventional Ni / Cd and Ni / MH batteries as well as the more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of significantly higher energy density compared to conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight manner, making them suitable for use as power sources for mobile devices. Recently, their scope of application has expanded to include electric vehicles, drawing attention as a next-generation energy storage medium.

[0003] Battery materials exhibit various behaviors, such as hysteresis, depending on the lithiation / delithiation state. While these diverse behaviors resulting from lithiation / delithiation can be ignored if they do not differ significantly from general behavior, various path dependencies may appear in cases like iron phosphate, where the properties of the lithium-rich phase and lithium-poor phase differ significantly.

[0004] While an algorithm for the diffusion of a single particle from the surface to the core has been proposed, an additional algorithm may be required to simulate the phase transition behavior of two-particle battery active materials. Prior art literature

[65535] Japanese Patent Publication No. JP 2014-120200 (Published June 30, 2014) GK Singh et al., Electrochimica Acta 53 (2008), 7599-7613 The problem to be solved

[0005] One objective of the embodiments disclosed in this document is to provide a battery management device capable of simulating the phase transition behavior of a battery active material and a method of operating the same.

[0006] The present invention provides a battery management device and a method of operation thereof that calculates information related to crosstalk between a lithium-rich phase and a lithium-poor phase by solving an active material concentration conservation equation of the embodiments disclosed in this document.

[0007] The technical problems of the embodiments disclosed in this document are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0008] A battery management device according to one embodiment disclosed in this document may include an information acquisition unit that acquires information regarding two different phases of a battery active material and a controller that calculates information related to crosstalk between the two different phases based on the information regarding the two different phases of the battery active material.

[0009] In one embodiment, the controller can simulate the phase transition of the battery active material by calculating information related to the crosstalk.

[0010] In one embodiment, the two different phases may include a lithium rich phase and a lithium poor phase.

[0011] In one embodiment, the controller can estimate the diffusion coefficient of the crosstalk as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase.

[0012] In one embodiment, the controller can fit the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and voltage curve.

[0013] In one embodiment, the average may include an arithmetic mean or a harmonic mean.

[0014] In one embodiment, the voltage curve may be a voltage curve of a rest period in which there is no applied current to the battery.

[0015] In one embodiment, the controller can calculate information related to the crosstalk based on an active material concentration conservation equation based on lithium concentration and a lithium diffusion coefficient.

[0016] In one embodiment, the active material concentration conservation equation may be [Equation 1].

[0017] [Mathematical Formula 1]

[0018]

[0019]

[0020] In one embodiment, the controller can calculate information related to the crosstalk by solving the active material concentration conservation equation based on boundary conditions related to reaction current density, active material radial coordinates, lithium concentration, lithium diffusion coefficient, effective radius, and surface current density.

[0021] In one embodiment, the boundary conditions may be [Equation 2] to [Equation 8].

[0022] [Mathematical Formula 2]

[0023] , r: coordinates in the direction of the active material radius

[0024] [Mathematical Formula 3]

[0025]

[0026]

[0027] [Mathematical Formula 4]

[0028]

[0029] [Mathematical Formula 5]

[0030]

[0031] [Mathematical Formula 6]

[0032]

[0033]

[0034]

[0035] [Mathematical Formula 7]

[0036]

[0037]

[0038] [Mathematical Formula 8]

[0039]

[0040]

[0041] In one embodiment, information related to the crosstalk may include at least one of the diffusion coefficient of the crosstalk, the flux of the crosstalk, and the diffusion distance of the crosstalk.

[0042] A method of operation of a battery management device according to one embodiment disclosed in this document may include the step of obtaining information regarding two different phases of a battery active material and the step of calculating information related to crosstalk between the two different phases based on the information regarding the two different phases of the battery active material.

[0043] In one embodiment, the two different phases may include a lithium rich phase and a lithium poor phase.

[0044] In one embodiment, the step of calculating information related to crosstalk between two different phases based on information regarding two different phases of the battery active material may include the step of estimating the diffusion coefficient of the crosstalk as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase, and the step of fitting the diffusion coefficient of the crosstalk based on the estimated diffusion coefficient of the crosstalk and the voltage curve. Effects of the invention

[0045] A battery management device and a method of operation thereof according to one embodiment disclosed in this document can simulate the phase transition behavior of an active material.

[0046] A battery management device and a method of operation thereof according to one embodiment disclosed in this document can calculate the diffusion between a lithium-rich phase and a lithium-poor phase by solving an active material concentration conservation equation based on boundary conditions.

[0047] A battery management device and a method of operation thereof according to one embodiment disclosed in this document can estimate a crosstalk diffusion coefficient as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase, and fit the diffusion coefficient based on the estimated crosstalk diffusion coefficient and the voltage curve.

[0048] In addition, various effects that can be identified directly or indirectly through this document may be provided. Brief explanation of the drawing

[0049] FIG. 1 is a block diagram showing a battery management device according to one embodiment disclosed in this document. FIG. 2 is a drawing showing an example of an analytical grid that simulates the phase transition behavior of an active material in a battery management device according to one embodiment disclosed in this document. FIG. 3 is a drawing showing an example of a voltage hysteresis phenomenon according to one embodiment disclosed in this document. FIG. 4 is a flowchart showing the operation method of a battery management device according to one embodiment disclosed in this document. FIG. 5 is a flowchart specifically showing the operation method of a battery management device according to one embodiment disclosed in this document. FIG. 6 is a block diagram showing the hardware configuration of a computing system for performing a method of operation of a battery management device according to one embodiment disclosed in this document. Specific details for implementing the invention

[0050] The embodiments disclosed in this document are described in detail below with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments disclosed in this document, detailed descriptions of related known configurations or functions are omitted if it is determined that such detailed descriptions would hinder understanding of the embodiments disclosed in this document.

[0051] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended only to distinguish the components from other components and do not limit the essence, order, or sequence of the components. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments disclosed in this document belong. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0052] FIG. 1 is a block diagram showing a battery management device according to one embodiment disclosed in this document.

[0053] Referring to FIG. 1, a battery management device (100) according to one embodiment disclosed in this document may include an information acquisition unit (110) and a controller (120).

[0054] The information acquisition unit (110) can acquire information regarding two different phases of the battery active material. For example, the two different phases of the battery active material may include a lithium rich phase and a lithium poor phase. As another example, the information acquisition unit (110) can acquire information regarding the lithium rich phase and information regarding the lithium poor phase. For example, the information acquisition unit (110) can acquire the lithium concentration of the lithium rich phase, the lithium diffusion coefficient of the lithium rich phase, the effective radius of the lithium rich phase, the surface current density of the lithium rich phase, the lithium concentration of the lithium poor phase, the lithium diffusion coefficient of the lithium poor phase, the effective radius of the lithium poor phase, the surface current density of the lithium poor phase, etc. Additionally, the information acquisition unit (110) can acquire the area of ​​the lithium-rich phase, the effective radius of the lithium-rich phase, the current density of the lithium-rich phase, the volume fraction of the lithium-rich phase, the area of ​​the lithium-poor phase, the effective radius of the lithium-poor phase, the current density of the lithium-poor phase, and the volume fraction of the lithium-poor phase.

[0055] According to the embodiment, the lithium-rich phase may include particles such as LiFePO4, and the lithium-poor phase may include particles such as FePO4.

[0056] The controller (120) can calculate information related to crosstalk between the lithium-rich phase and the lithium-poor phase based on information regarding the lithium-rich phase and information regarding the lithium-poor phase. For example, the controller (120) can calculate information related to crosstalk based on an active material concentration conservation equation based on lithium concentration and lithium diffusion coefficient. As another example, crosstalk may be diffusion between different active materials. As yet another example, crosstalk may be diffusion between the lithium-rich phase and the lithium-poor phase in the LFP. According to an embodiment, information related to crosstalk may include the flux of crosstalk, the diffusion coefficient of crosstalk, etc.

[0057] Materials similar to LFP (lithium iron phosphate) may exhibit lithium 2-phase behavior. Materials similar to LFP exhibit an open-circuit voltage (OCV) that changes at a very slow rate during rest or relaxed conditions without applied current, which can be implemented by calculating information related to crosstalk between the 2-phases. According to an embodiment, the controller (120) can simulate the phase transition of lithium by calculating information related to crosstalk between the 2-phases.

[0058] According to the example, the active material concentration conservation equation can be expressed as [Equation 1] below.

[0059] [Mathematical Formula 1]

[0060]

[0061]

[0062] The controller (120) can calculate diffusion by solving the active material concentration conservation equation based on boundary conditions related to reaction current density, active material radial coordinates, lithium concentration, lithium diffusion coefficient, effective radius, and surface current density. For example, the boundary conditions may be as shown in [Equation 2] to [Equation 8] below.

[0063] [Mathematical Formula 2]

[0064] , r: coordinates in the direction of the active material radius

[0065] [Mathematical Formula 3]

[0066]

[0067]

[0068] [Mathematical Formula 4]

[0069]

[0070] [Mathematical Formula 5]

[0071]

[0072] [Mathematical Formula 6]

[0073]

[0074]

[0075]

[0076] [Mathematical Formula 7]

[0077]

[0078]

[0079] [Mathematical Formula 8]

[0080]

[0081]

[0082] The controller (120) can solve the active material concentration conservation equation of [Equation 1] based on conditions satisfying [Equation 2] to [Equation 8].

[0083] Additionally, the controller (120) may additionally consider [Equation 9] to [Equation 12] to calculate values ​​related to the lithium-rich phase and the lithium-poor phase in order to calculate the diffusion.

[0084] [Mathematical Formula 9]

[0085]

[0086]

[0087]

[0088] [Mathematical Formula 10]

[0089]

[0090]

[0091] [Mathematical Formula 11]

[0092]

[0093]

[0094] [Mathematical Formula 12]

[0095]

[0096]

[0097] According to an embodiment, the controller (120) can simulate the phase transition of lithium by calculating information related to crosstalk.

[0098] According to an embodiment, the controller (120) Information related to crosstalk can be produced by calculating .

[0099] According to an embodiment, the controller (120) It can be calculated by fitting based on test data. For example, the controller (120) is the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase. It is possible to estimate the crosstalk diffusion coefficient and calculate it by fitting based on the estimated value and the experimental value.

[0100] According to an embodiment, the controller (120) can estimate the crosstalk diffusion coefficient as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase. For example, the average may include an arithmetic mean and / or a harmonic mean.

[0101] According to an embodiment, the controller (120) can fit the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and the voltage curve. For example, the voltage curve may be a measured value and may be a voltage curve during a rest period (or relaxed period) when there is no applied current to the battery. As another example, since the effect of flattening the distribution of salt in the electrolyte may be significant at the beginning of the rest period, the controller (120) can fit based on the voltage curve after the effect of the electrolyte has been minimized (e.g., after 6 hours).

[0102] According to an embodiment, the controller (120) has a crosstalk flux ( ...can be calculated. For example, the crosstalk flux may be proportional to the concentration gradient of the concentration difference according to the diffusion distance. For example, the crosstalk flux may refer to a unit physical quantity passing through a unit area per unit time. According to an example, the crosstalk flux may refer to the diffusion rate of particles.

[0103] A battery management device (100) according to one embodiment disclosed in this document can simulate diffusion between two particles. For example, the battery management device (100) can simulate a phase transition of an active material by calculating information related to crosstalk between a lithium-rich phase particle and a lithium-poor phase particle.

[0104] A battery management device (100) according to one embodiment disclosed in this document is

[0105] FIG. 2 is a drawing showing an example of an analytical grid that simulates the phase transition behavior of an active material in a battery management device according to one embodiment disclosed in this document.

[0106] Referring to Fig. 2, lithium-rich phase particles and lithium-poor phase particles can be simultaneously included within the computational grid.

[0107] In the phase transition simulation algorithm, the fractions occupied by the lithium-rich phase and the lithium-poor phase can change depending on the change in the Li stoichiometry ratio within the particles. Therefore, according to the change in the Li stoichiometry ratio, the area in which the lithium-rich phase and the lithium-poor phase participate in electrochemical reactions can also change, and reactions with the electrolyte can occur in parallel.

[0108] In addition, the lithium-rich phase and the lithium-poor phase can have independent physical properties. For example, the lithium-rich phase and the lithium-poor phase may differ in characteristics such as open-circuit voltage (OCV), lithium diffusion coefficient, electrical conductivity, and thermal conductivity.

[0109] Additionally, the controller (120) of Fig. 1 can produce information related to crosstalk between the lithium-rich phase and the lithium-poor phase, and in this case, mass conservation can be maintained.

[0110] In addition, the phase transition simulation algorithm may have a single-phase region in which only one of the lithium-rich phase or lithium-poor phase exists depending on the change in the Li stoichiometry ratio value.

[0111] FIG. 3 is a drawing showing an example of a battery management device managing a voltage history phenomenon according to one embodiment disclosed in this document.

[0112] The battery voltage during a rest or relaxed period when there is no applied current to the battery can converge to the open-circuit voltage (OCV). In this case, the open-circuit voltage can be expressed as a function related to lithiation within the active material.

[0113] The battery management device (100) illustrated in Fig. 1 can perform calculations by applying different open-circuit voltage curves to the lithium-rich phase and the lithium-poor phase, respectively, when there is a hysteresis phenomenon of the open-circuit voltage as shown in the graph in Fig. 3, and can calculate the open-circuit voltage so that it converges to a single point within the voltage hysteresis phenomenon after a long time in the dormant section, and the speed of convergence can be adjusted by fitting a crosstalk coefficient.

[0114] Furthermore, if the concentrations of the lithium-rich phase and lithium-poor phase change due to crosstalk during the dormant period, the equilibrium potential changes, and consequently, the cell voltage can shift to a new equilibrium potential. Depending on the type of material, the environment, or various other conditions, if crosstalk is slow, it takes a long time for the cell's equilibrium voltage to reach the changed equilibrium voltage, whereas if crosstalk is fast, the time to reach the changed equilibrium voltage can be relatively short.

[0115] FIG. 4 is a flowchart showing the operation method of a battery management device according to one embodiment disclosed in this document.

[0116] Referring to FIG. 4, the method of operation of a battery management device (100) according to one embodiment disclosed in this document may include a step (S110) of obtaining information regarding two different phases of a battery active material and a step (S120) of calculating information regarding crosstalk between two different phases based on the information regarding two different phases of a battery active material.

[0117] In the step (S110) of acquiring information regarding two different phases of a battery active material, the information acquisition unit (110) can acquire information regarding two different phases of a battery active material (e.g., LFP). For example, the two different phases of the battery active material may include a lithium rich phase and a lithium poor phase. As another example, the information acquisition unit (110) can acquire the lithium concentration of the lithium rich phase, the lithium diffusion coefficient of the lithium rich phase, the effective radius of the lithium rich phase, the surface current density of the lithium rich phase, the lithium concentration of the lithium poor phase, the lithium diffusion coefficient of the lithium poor phase, the effective radius of the lithium poor phase, the surface current density of the lithium poor phase, etc. Additionally, the information acquisition unit (110) can acquire the area of ​​the lithium-rich phase, the effective radius of the lithium-rich phase, the current density of the lithium-rich phase, the volume fraction of the lithium-rich phase, the area of ​​the lithium-poor phase, the effective radius of the lithium-poor phase, the current density of the lithium-poor phase, and the volume fraction of the lithium-poor phase.

[0118] In the step (S120) of calculating information related to crosstalk between two different phases based on information regarding two different phases of the battery active material, the controller (120) can calculate information related to crosstalk between the lithium rich phase and the lithium poor phase based on information regarding the lithium rich phase and information regarding the lithium poor phase. For example, the controller (120) can calculate information related to crosstalk by solving the active material concentration conservation equation. As another example, the controller (120) can calculate information related to crosstalk based on [Equation 1] to [Equation 12].

[0119] FIG. 5 is a flowchart specifically showing the operation method of a battery management device according to one embodiment disclosed in this document.

[0120] Referring to FIG. 5, the operation method of the battery management device (100) may include a step (S210) of estimating the crosstalk diffusion coefficient as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase, and a step (S220) of fitting the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and voltage curve. According to an embodiment, steps S210 and S220 may be included in step S120 of FIG. 4.

[0121] In the step (S210) of estimating the crosstalk diffusion coefficient as the average of the diffusion coefficients of the lithium-rich phase and the lithium-poor phase, the controller (120) can estimate the crosstalk diffusion coefficient as the average of the diffusion coefficients of the lithium-rich phase and the lithium-poor phase. For example, the average may include an arithmetic mean and / or a harmonic mean.

[0122] Step (S220) of fitting the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and voltage curve. The controller (120) can fit the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and voltage curve. For example, the voltage curve may be a voltage curve of a rest, relax period in which there is no applied current to the battery.

[0123] FIG. 6 is a block diagram showing the hardware configuration of a computing system for performing a method of operation of a battery management device according to one embodiment disclosed in this document.

[0124] Referring to FIG. 6, a computing system (1000) according to one embodiment disclosed in this document may include an MCU (1010), a memory (1020), an input / output I / F (1030), and a communication I / F (1040).

[0125] The MCU (1010) may be a processor that executes various programs stored in memory (1020) (e.g., a battery pack voltage or current collection program, a battery cell phase transition algorithm simulation program, a battery cell diffusion calculation program, etc.), processes various information including the voltage, current, temperature, lithium concentration, surface current density, lithium diffusion coefficient, effective radius, crosstalk, etc. of the battery cell through these programs, and performs the functions of a controller included in the battery management device shown in FIG. 1.

[0126] The memory (1020) can store various programs such as the capacity of the battery cell, voltage collection, diffusion calculation, phase transition algorithm simulation program, and charge / discharge control program. In addition, the memory (1020) can store various information such as the current, voltage, temperature, lithium concentration, surface current density, lithium diffusion coefficient, and effective radius of the battery cell.

[0127] These memories (1020) may be provided in multiple quantities as needed. The memories (1020) may be volatile memories or non-volatile memories. As volatile memories, the memory (1020) may use RAM, DRAM, SRAM, etc. As non-volatile memories, the memory (1020) may use ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. The examples of the memories (1020) listed above are merely examples and are not limited to these examples.

[0128] The input / output I / F (1030) can provide an interface that enables data transmission and reception between an input device (not shown), such as a keyboard, mouse, or touch panel, an output device (not shown), and an MCU (1010).

[0129] The communication I / F (1040) is configured to transmit and receive various data with a server and may be various devices capable of supporting wired or wireless communication. For example, the battery management device can transmit and receive information such as voltage, current, lithium concentration, surface current density, lithium diffusion coefficient, effective radius, and crosstalk of various battery cells from a separately provided external server via the communication I / F (1040).

[0130] In this way, a computer program according to one embodiment disclosed in this document may be implemented as a module that performs, for example, the functions illustrated in FIG. 1 by being written to memory (1020) and processed by an MCU (1010).

[0131] The above description is merely an illustrative explanation of the technical concept disclosed in this document, and a person skilled in the art to which the embodiments disclosed in this document belong may make various modifications and variations within the scope of the essential characteristics of the embodiments disclosed in this document.

[0132] Accordingly, the embodiments disclosed in this document are intended to illustrate, not limit, the technical concept disclosed in this document, and the scope of the technical concept disclosed in this document is not limited by these embodiments. The scope of protection of the technical concept disclosed in this document shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this document. Explanation of the symbols

[0133] 100: Battery Management Unit 110: Information Acquisition Department 120: Controller 1000: Computing System 1010: MCU 1020: Memory 1030: Input / Output I / F 1040: Communication I / F

Claims

Claim 1 A battery management device comprising: an information acquisition unit for acquiring information regarding two different phases of a battery active material; and a controller for calculating information related to crosstalk between the two different phases based on information regarding the two different phases of the battery active material, wherein the two different phases include a lithium rich phase and a lithium poor phase, and the crosstalk represents diffusion between the two different phases. Claim 2 A battery management device according to claim 1, wherein the controller calculates information related to the crosstalk to simulate the phase transition of the battery active material. Claim 3 delete Claim 4 A battery management device according to claim 1, wherein the controller estimates the diffusion coefficient of the crosstalk as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase. Claim 5 In claim 4, the controller fits the crosstalk diffusion coefficient based on the estimated crosstalk diffusion coefficient and voltage curve, and the voltage curve is a curve representing a voltage change according to the capacity of the battery, a battery management device. Claim 6 A battery management device according to claim 5, wherein the voltage curve is a voltage curve of a rest period in which there is no applied current to the battery. Claim 7 A battery management device according to claim 4, wherein the average includes an arithmetic mean or a harmonic mean. Claim 8 A battery management device according to claim 1, wherein the controller calculates information related to the crosstalk based on an active material concentration conservation equation based on lithium concentration and a lithium diffusion coefficient, and the active material concentration conservation equation is [Equation 1]. [Equation 1] ▽: Gradient operator Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 A battery management device according to claim 1, wherein the information related to the crosstalk includes at least one of the diffusion coefficient of the crosstalk, the flux of the crosstalk, and the diffusion distance of the crosstalk, wherein the flux of the crosstalk includes a value representing the diffusion rate of lithium between the two different phases, and the diffusion distance of the crosstalk includes a value representing the diffusion distance of lithium between the two different phases. Claim 13 A method of operation of a battery management device comprising: a step of obtaining information regarding two different phases of a battery active material; and a step of calculating information related to crosstalk between the two different phases based on the information regarding the two different phases of the battery active material, wherein the two different phases include a lithium rich phase and a lithium poor phase, and the crosstalk represents diffusion between the two different phases. Claim 14 delete Claim 15 In claim 13, the step of calculating information related to crosstalk between two different phases based on information regarding two different phases of the battery active material comprises: a step of estimating the diffusion coefficient of the crosstalk as the average of the diffusion coefficient of the lithium-rich phase and the diffusion coefficient of the lithium-poor phase; and a step of fitting the diffusion coefficient of the crosstalk based on the estimated diffusion coefficient of the crosstalk and the voltage curve; wherein the voltage curve is a curve representing a voltage change according to the capacity of the battery.

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