Analysis method and analysis device

Abstract

This analysis method comprises: performing molecular dynamics calculations on an electrolyte to calculate the behavior over time of a series of atoms that make up constituent components of the electrolyte; calculating a first dielectric relaxation spectrum signal of the constituent components on the basis of the behavior of the series of atoms over time; calculating a second dielectric relaxation spectrum signal of the electrolyte on the basis of the first dielectric relaxation spectrum signal; and calculating physical property values specific to the constituent components on the basis of the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal.

Description

Analysis method and analysis device

[0001] The present technology relates to an analysis method and an analysis device.

[0002] In order to design the composition of an electrolyte solution used in an electricity storage device, various analytical methods and analytical devices have been proposed for analyzing the physical properties of the electrolyte solution.

[0003] Specifically, in a preliminary study of an electrolyte solution, a calibration model representing the relationship between the intensity of the complex dielectric constant in a specific frequency band and the concentration is prepared, and the complex dielectric constant is measured in the specific frequency band, and the concentration of the electrolyte solution is determined based on the measurement result of the complex dielectric constant (see, for example, Patent Document 1).

[0004] Furthermore, nuclear magnetic resonance (NMR) is used to determine the rotational correlation time, molecular weight, and molecular volume of a molecule based on a spectral signal obtained from an electrolyte solution in response to a magnetic field (see, for example, Patent Document 2).

[0005] JP 2019-190896 A JP 2006-317311 A

[0006] Although various studies have been conducted on analytical methods and analytical devices for analyzing the physical properties of electrolytes, the level of analysis is still insufficient and there is room for improvement.

[0007] An analytical method and an analytical device are provided that are capable of easily and highly accurately analyzing the physical properties of an electrolyte solution.

[0008] An analysis method according to one embodiment of the present technology calculates the behavior over time of a series of atoms constituting a constituent component of the electrolyte solution by performing a molecular dynamics calculation on the electrolyte solution, calculates a first dielectric relaxation spectrum signal of the constituent component based on the behavior over time of the series of atoms, calculates a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal, and calculates physical property values ​​specific to the constituent component based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal.

[0009] An analysis device according to one embodiment of the present technology includes a calculation unit that calculates physical property values ​​related to an electrolyte solution, and the calculation unit calculates the behavior over time of a series of atoms that constitute a constituent component of the electrolyte solution by performing molecular dynamics calculations on the electrolyte solution, calculates a first dielectric relaxation spectrum signal of the constituent component based on the behavior over time of the series of atoms, calculates a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal, and calculates physical property values ​​specific to the constituent component based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal.

[0010] According to an analysis method or analysis device of an embodiment of the present technology, by performing a molecular dynamics calculation on an electrolyte solution, the behavior over time of a series of atoms constituting the constituent components of the electrolyte solution is calculated, a first dielectric relaxation spectrum signal of the constituent components is calculated, a second dielectric relaxation spectrum signal of the electrolyte solution is calculated, and physical property values ​​specific to the constituent components are calculated, thereby making it possible to analyze the physical properties of the electrolyte solution easily and with high accuracy.

[0011] Note that the effects of the present technology are not necessarily limited to the effects described here, but may be any of a series of effects related to the present technology described below.

[0012] FIG. 1 is a block diagram showing the configuration of an analysis device in a first embodiment of the present technology. FIG. 2 is a block diagram showing the configuration of an analysis device in a modified example 2. FIG. 3 is a calculation result of a time correlation function in Example 1. FIG. 4 is an approximation result of a time correlation function in Example 1. FIG. 5 is a calculation result of an individual calculated dielectric relaxation spectrum signal (real part of dielectric constant) and a calculated dielectric relaxation spectrum signal (real part of dielectric constant) in Example 1. FIG. 6 is a calculation result of an individual calculated dielectric relaxation spectrum signal (imaginary part of dielectric constant) and a calculated dielectric relaxation spectrum signal (imaginary part of dielectric constant) in Example 1. FIG. 7 is a calculation result of a calculated dielectric relaxation spectrum signal (real part of dielectric constant and imaginary part of dielectric constant) in Example 1. FIG. 8 is a measurement result of a measured dielectric relaxation spectrum signal (real part of dielectric constant and imaginary part of dielectric constant) in Example 1. FIG. 9 is a calculation result of an individual calculated dielectric relaxation spectrum signal (imaginary part of dielectric constant) and a calculated dielectric relaxation spectrum signal (imaginary part of dielectric constant) in Example 2. FIG. 10 is a calculation result of a calculated dielectric relaxation spectrum signal (real part of dielectric constant and imaginary part of dielectric constant) in Example 2. 1 shows the measurement results of the measured dielectric relaxation spectrum signals (dielectric constant real part and dielectric constant imaginary part) in Example 2. FIG. 2 shows the calculation results of the individually calculated dielectric relaxation spectrum signals (dielectric constant imaginary part) in Example 3 (three-component system). FIG. 3 shows the calculation results of the individually calculated dielectric relaxation spectrum signals (dielectric constant imaginary part) in Example 3 (two-component system). FIG. 4 shows the calculation results of the calculated dielectric relaxation spectrum signals (dielectric constant real part and dielectric constant imaginary part) in Example 3. FIG. 5 shows the measurement results of the actually measured dielectric relaxation spectrum signals (dielectric constant real part and dielectric constant imaginary part) in Example 3.

[0013] Hereinafter, an embodiment of the present technology will be described in detail with reference to the drawings. The description will be given in the following order: 1. Analysis device and analysis method (first embodiment) 1-1. Analysis device 1-2. Analysis method 1-3. Actions and effects 2. Analysis device and analysis method (second embodiment) 2-1. Analysis device 2-2. Analysis method 2-3. Actions and effects 3. Modified example

[0014] 1. Analysis Device and Analysis Method (First Embodiment) First, an analysis device according to a first embodiment of the present technology will be described.

[0015] Note that the analysis method in the first embodiment of the present technology will be explained by the operation (analysis procedure) of the analysis device explained here, and therefore the analysis method will also be explained below.

[0016] This analyzer is used to analyze the physical properties of an electrolyte solution, and the analysis results are used as guidelines for designing the composition of an electrolyte solution with desired performance. This electrolyte solution contains one or more constituent components, and the analyzer analyzes the physical properties of the electrolyte solution as a whole, as well as the physical properties of each constituent component contained in the electrolyte solution.

[0017] The one or more constituent components described herein include one or more of neutral molecules and ion pairs. The number of types of neutral molecules may be one or more. Similarly, the number of types of ion pairs may be one or more. Details of the neutral molecules and ion pairs will be described later.

[0018] The electrolytic solution is a liquid electrolyte having ion conductivity and contains a solvent and an electrolyte salt. Details of the solvent and the electrolyte salt will be described later. The use of the electrolytic solution is not particularly limited, but examples include electricity storage devices such as batteries and capacitors. The battery may be a primary battery or a secondary battery.

[0019] This makes it possible to design the composition of an electrolyte solution having desired performance based on the analysis results of the electrolyte solution using the analysis device, and therefore the analysis method using the analysis device is useful for research and development, design, and quality control of electrolyte solutions used in a variety of applications.

[0020] Specifically, the mobility (especially rotational mobility) of each component contained in an electrolyte is an important factor that significantly affects the ion transport properties of the electrolyte. Therefore, by analyzing an electrolyte using an analytical device, it is possible to understand the overall physical properties of the electrolyte, which reflect the physical properties resulting from the mobility of each component, as well as the physical properties of each component resulting from that mobility. This makes it possible to easily and accurately design the composition of an electrolyte with excellent ion transport properties.

[0021] In particular, the analysis device described herein uses molecular dynamics calculations to calculate the dielectric relaxation spectrum signal of each component in order to analyze the physical properties of the electrolyte, more specifically, the physical properties of each component contained in the electrolyte.

[0022] Hereinafter, the molecular dynamics calculation will be referred to as "MD calculation" and the dielectric relaxation spectrum signal will be referred to as "DRS signal."

[0023] The MD calculation is a simulation that calculates the behavior of a series of atoms that make up each component over time. The DRS signal is a signal that represents the dielectric behavior of a material (a so-called complex permittivity spectrum signal), and includes a real part and an imaginary part of the permittivity.

[0024] <1-1. Analysis Device> Fig. 1 shows a block configuration of an analysis device 100, which is a specific example of an analysis device in the first embodiment. As shown in Fig. 1, this analysis device 100 includes a calculation unit 10, a measurement unit 20, and a comparison unit 30.

[0025] [Calculation Unit] The calculation unit 10 calculates a physical property value P for an electrolyte solution containing a constituent component C. As described above, the type of constituent component C may be one type or two or more types. The type of physical property value P is not particularly limited, and may be one type or two or more types. Specifically, the physical property value P includes one or two or more types of characteristic time, relaxation strength, static dielectric constant, concentration, and salt dissociation degree. Details of the characteristic time, relaxation strength, static dielectric constant, concentration, and salt dissociation degree will be described later.

[0026] The calculation unit 10 includes a processing element that performs a series of calculation processes such as MD calculations, and a specific example of the processing element is a microprocessor.

[0027] Specifically, the calculation unit 10 performs MD calculations on the electrolyte to calculate the behavior over time of a series of atoms that make up the constituent component C. This MD calculation tracks the change over time in the behavior (position and energy) of each atom that makes up the substance by solving Newton's equations of motion in classical mechanics.

[0028] The MD calculation method (including the type of force field) is not particularly limited as long as the software is capable of executing the MD calculation. In this case, the conditions for the MD calculation can be set arbitrarily.

[0029] Furthermore, the calculation unit 10 calculates the DRS signal of the constituent C based on the calculation results using the MD calculation, i.e., the calculation results of the behavior of a series of atoms over time. Specifically, the calculation unit 10 calculates the DRS signal of the constituent C based on the calculation results using the MD calculation, and also calculates the DRS signal of the entire electrolyte based on the DRS signal of the constituent C.

[0030] The former DRS signal is a DRS signal (first dielectric relaxation spectrum signal) of component C calculated by the calculation unit 10, and hereinafter this DRS signal is referred to as an "individually calculated DRS signal S1." The latter DRS signal is a DRS signal (second dielectric relaxation spectrum signal) of the electrolyte solution calculated by the calculation unit 10, and hereinafter this DRS signal is referred to as a "calculated DRS signal S2."

[0031] When there is one type of constituent C, the calculation unit 10 calculates an individual calculated DRS signal S1 and then sets the individual calculated DRS signal S1 as the calculated DRS signal S2. On the other hand, when there are two or more types of constituent C, the calculation unit 10 calculates an individual calculated DRS signal S1 for each constituent C and then adds the individual calculated DRS signals S1 for each constituent C to calculate the calculated DRS signal S2.

[0032] The calculation unit 10 calculates not only the calculated DRS signal S2 of the electrolyte but also the individual calculated DRS signal S1 of the constituent C in order to make it possible to attribute the DRS signal (measured DRS signal S3) measured by the actual measurement unit 20 using the individual calculated DRS signal S1, as described below.

[0033] Furthermore, the calculation unit 10 calculates a physical property value P specific to the constituent component C based on the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0034] Here, the calculation unit 10 sequentially performs the calculation processes described below to calculate the individually calculated DRS signal S1. That is, the calculation unit 10 calculates the total electric dipole moment of the component C based on the calculation result of the MD calculation. Furthermore, the calculation unit 10 calculates the time correlation function of the component C based on the calculation result of the total electric dipole moment, and then approximates the calculation result of the time correlation function to an exponential function. Furthermore, the calculation unit 10 calculates the individually calculated DRS signal S1 of the component C by Fourier transforming the approximation result of the time correlation function.

[0035] When the electrolyte solution contains two or more constituent components C, an individual calculated DRS signal S1 is calculated for each of the constituent components C, resulting in multiple individual calculated DRS signals S1. Therefore, as described above, the multiple individual calculated DRS signals S1 are added together to calculate the calculated DRS signal S2 of the electrolyte solution.

[0036] Hereinafter, the calculation procedure for the individually calculated DRS signal S1 in the first embodiment will be referred to as "calculation procedure 1" to distinguish it from the calculation procedure for the individually calculated DRS signal S1 in the second embodiment described later.

[0037] The details of the functions of calculation unit 10 described here will be specifically explained when explaining the operation (analysis procedure) of analysis device 100 described later.

[0038] The calculation unit 10 calculates the individual calculated DRS signal S1 and the calculated DRS signal S2, and then outputs data D1 to the comparison unit 30. The data D1 includes information such as the individual calculated DRS signal S1, the calculated DRS signal S2, and the physical property value P.

[0039] [Measurement Unit] The measurement unit 20 measures the DRS signal of the electrolyte solution by analyzing the electrolyte solution using dielectric relaxation spectroscopy. This DRS signal is the DRS signal (third dielectric relaxation spectrum signal) of the electrolyte solution measured by the measurement unit 20, and hereinafter, this DRS signal will be referred to as the "measured DRS signal S3." Dielectric relaxation spectroscopy is a useful analytical technique that can grasp the ion transport properties of the electrolyte solution as well as the mobility of each constituent component C that affects the ion transport properties.

[0040] After measuring the measured DRS signal S3, the measurement unit 20 corrects the measured DRS signal S3. In this case, the measurement unit 20 preferably corrects the measured DRS signal S3 by removing errors caused by the ionic conductivity of the electrolyte from the measured DRS signal S3. This is because errors caused by physical properties other than the mobility of each component C are eliminated, thereby improving the measurement accuracy of the measured DRS signal S3.

[0041] Here, the measurement unit 20 includes a dielectric spectroscopy unit and a correction unit, not shown.

[0042] The dielectric spectroscopy unit measures the measured DRS signal S3 by irradiating the electrolyte with electromagnetic waves and receiving a response wave from the electrolyte. The method for measuring the measured DRS signal S3 is not particularly limited, but as an example, the reflection transmission method (S-parameter method) is preferred. This is because it allows the measured DRS signal S3 of the liquid (here, the electrolyte) to be measured with high accuracy. After measuring the measured DRS signal S3, the dielectric spectroscopy unit outputs the measurement result of the measured DRS signal S3 to the correction unit.

[0043] More specifically, the dielectric spectroscopy unit includes a measurement cell, a transmitter, a receiver, a dielectric spectroscopy sensor, and a computing element.

[0044] The measurement cell is a container that contains an electrolytic solution. The electrolytic solution contained in the measurement cell preferably does not contain any air bubbles. The amount of the electrolytic solution contained in the measurement cell is preferably an appropriate amount that can be contacted by a probe, which will be described later.

[0045] The transmitter irradiates the electrolyte solution contained in the measurement cell with electromagnetic waves such as microwaves. The frequency of the microwaves is not particularly limited, but is, for example, 100 MHz to 100 GHz.

[0046] The receiver receives a response wave from the measurement cell via the dielectric spectroscopic sensor, the response wave including an electromagnetic wave reflected by the electrolyte and an electromagnetic wave transmitted through the electrolyte.

[0047] The calculation element calculates the measured DRS signal S3 based on the amplitude and phase of the response wave received by the receiver. A specific example of the calculation element is a microprocessor.

[0048] The specific configuration of the dielectric spectroscopy unit is not particularly limited. For example, the dielectric spectroscopy unit that measures the measured DRS signal S3 using the reflection transmission method is a vector network analyzer (VNA) to which an open-ended probe is connected via a microwave coaxial cable. This probe is connected to the measurement cell via two ports (a first port and a second port), and the microwave coaxial cable is a coaxial cable that corresponds to the frequency band of the microwaves irradiated to the electrolyte.

[0049] The dielectric spectroscopy unit using this reflection-transmission method calculates the measured DRS signal S3 using reflection coefficients S11 and S22, which are defined as the reflected wave / incident wave. The reflection coefficient S11 is the reflection coefficient corresponding to the first port, and the reflection coefficient S22 is the reflection coefficient corresponding to the second port.

[0050] The correction unit corrects the measurement results of the measured DRS signal S3 measured by the dielectric spectroscopy unit. The correction method of the correction unit is not particularly limited and can be set arbitrarily. In particular, in order to focus on the rotational portion of the molecular motion of each constituent component C, it is preferable that the correction unit removes errors caused by ionic conductivity (ionic conductivity) included in the measurement results of the measured DRS signal S3, as described above.

[0051] Specifically, when the measured DRS signal S3 is input from the dielectric spectroscopy unit, the correction unit performs fitting using a so-called Debye relaxation function on the imaginary part of the measured DRS signal S3 in a frequency band of 500 MHz or higher, which is generally less susceptible to errors caused by the ionic conductivity of the electrolyte. As a result, the correction unit corrects the measured DRS signal S3 in a frequency band of less than 500 MHz by extrapolating the fitting result to the low frequency side.

[0052] As described above, the measured DRS signal S3 corresponding to the error removed by the correction unit represents the physical properties of each component C due to the ionic conduction phenomenon, and therefore the physical properties are information about the motility (ion transport property) other than the rotational motion. As a result, the measured DRS signal S3 removed by the correction unit may be used separately to grasp the physical properties of the electrolyte solution as information about the motility other than the rotational motion of each component C.

[0053] A specific example of the correction unit is a microprocessor.

[0054] Here, as described above, the measurement unit 20 includes a correction unit for correcting the measurement result of the measured DRS signal S3. However, if there is no need to correct the measurement result of the measured DRS signal S3, the measurement unit 20 does not need to include a correction unit.

[0055] The details of the functions of the measurement unit 20 described here will be specifically explained when explaining the operation (analysis procedure) of the analysis device 100 described later.

[0056] After measuring the measured DRS signal S3, the measuring section 20 outputs data D2 to the comparing section 30. The data D2 includes information such as the measured DRS signal S3.

[0057] The comparison unit 30 compares the calculated DRS signal S2 with the measured DRS signal S3 based on the data D1 input from the calculation unit 10 and the data D2 input from the measurement unit 20. As a result, the comparison unit 30 assigns the measured DRS signal S3 using the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2, depending on the comparison result between the calculated DRS signal S2 and the measured DRS signal S3. A specific example of the comparison unit 30 is a microprocessor.

[0058] That is, the comparison unit 30 confirms that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other. In this case, the comparison unit 30 compares the spectral shape of the calculated DRS signal S2 with the spectral shape of the measured DRS signal S3 to confirm that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other. As a result, when the comparison unit 30 confirms that the spectral shape of the calculated DRS signal S2 and the spectral shape of the measured DRS signal S3 qualitatively match each other, it determines that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other.

[0059] The comparison unit 30 includes a processor that performs a comparison between the calculated DRS signal S2 and the measured DRS signal S3 using image analysis processing. A specific example of the processor is a microprocessor. The comparison method is not particularly limited as long as it is software capable of executing the comparison. In this case, the comparison conditions can be set arbitrarily.

[0060] In addition, when the measurement unit 20 corrects the measured DRS signal S3, the comparison unit 30 compares the calculated DRS signal S2 with the correction result of the measured DRS signal S3 in order to attribute the calculated DRS signal S2 to the measured DRS signal S3.

[0061] Here, the measured DRS signal S3 actually measured by the measurement unit 20 using an electrolyte provides important information for investigating the physical properties (molecular-level mobility) of the electrolyte, but it is difficult to grasp the detailed physical properties of the electrolyte using only the measured DRS signal S3. This is because, when an electrolyte contains two or more types of constituent components C, the measured DRS signal S3 of the electrolyte is a signal obtained by adding together the DRS signals that should be measured for each constituent component C, but it is extremely difficult to measure a DRS signal for each constituent component C in the measurement unit 20. As a result, while it is possible to grasp the overall physical properties of the electrolyte using the measured DRS signal S3, it is extremely difficult to grasp the physical properties of each constituent component C that affect the overall physical properties of the electrolyte.

[0062] Therefore, in order to grasp not only the overall physical properties of the electrolyte but also the physical properties of each constituent component C, the comparison unit 30 acquires the calculated DRS signal S2 and the measured DRS signal S3, and then confirms that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other.

[0063] As described above, the measured DRS signal S3 measured by the measurement unit 20 is a single DRS signal measured for the electrolyte. In contrast, the calculated DRS signal S2 calculated by the calculation unit 10 is a DRS signal obtained by adding together the individual calculated DRS signals S1 calculated for each constituent C, as described above. Therefore, the calculated DRS signal S2 is a single DRS signal calculated for the electrolyte (calculated DRS signal S2) and includes the DRS signals calculated for each constituent C (individual calculated DRS signals S1).

[0064] As a result, when the comparison unit 30 confirms that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other, the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3 (in other words, the validity of the MD calculation) is guaranteed, and the reliability of the individual calculated DRS signals S1 that constitute the calculated DRS signal S2 is also guaranteed. Therefore, even if a DRS signal cannot be measured for each constituent component C, it is technically guaranteed that the individual calculated DRS signals S1 can be used as information representing the physical properties of each constituent component C, making it possible to attribute the measured DRS signal S3 using the individual calculated DRS signals S1.

[0065] The details of the functions of comparison section 30 described here will be specifically explained when explaining the operation (analysis procedure) of analysis device 100 described later.

[0066] The comparator 30 performs comparison and attribution based on the calculated DRS signal S2 and the measured DRS signal S3, and then outputs data D3 to the outside. The data D3 includes information such as the individual calculated DRS signal S1, the calculated DRS signal S2, the measured DRS signal S3, and the physical property value P.

[0067] [Others] Analysis device 100 may further include one or more of the other components.

[0068] Specific examples of other components include a display unit, a memory unit, and a power supply. The display unit displays the calculation results by the calculation unit 10, the measurement results by the measurement unit 20, and the comparison results (attribution results) by the comparison unit 30. The memory unit stores a series of calculation results calculated by the analysis device 100. The power supply is the power source for the analysis device 100.

[0069] [Electrolyte Solution] As described above, the electrolyte solution used in the analysis using the analysis device 100 contains a solvent and an electrolyte salt. However, the electrolyte solution may further contain one or more of various additives.

[0070] The solvent is one or more of media that disperse or dissolve the electrolyte salt, and may be an aqueous solvent or a non-aqueous solvent.

[0071] The type of non-aqueous solvent is not particularly limited, but examples include one or more of cyclic carbonate esters, chain carbonate esters, and chain carboxylate esters.

[0072] Specific examples of cyclic carbonates include ethylene carbonate and propylene carbonate. Specific examples of chain carbonates include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Specific examples of chain carboxylic acid esters include ethyl propionate and propyl propionate.

[0073] The electrolyte salt is a solute that is dispersed or dissolved in a solvent, and contains one or more metal salts. The type of metal salt is not particularly limited, but an example of the metal salt is lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium bis(fluorosulfonyl)imide (LiN(FSO 2 ) 2 ) and lithium bis(trifluoromethanesulfonyl)imide (LiN(CF 3 SO 2 ) 2 ) and the like.

[0074] As described above, component C contains one or more of neutral molecules and ion pairs.

[0075] Neutral molecules are electrically neutral molecules and are chemically and temporally stable components. The type of neutral molecule is not particularly limited, but an example is a solvent molecule.

[0076] An ion pair is an electrical bond between a cation and an anion. The type of ion pair is not particularly limited, but examples include contact ion pairs (CIP), solvent-separated ion pairs (SIP), and solvent-separated ion pairs (SSIP), and other electrical bonds may also be used.

[0077] As described above, the types of ions forming the ion pair are not particularly limited as long as they are two or more types. Therefore, the types of cations forming the ion pair may be one type or two or more types. Similarly, the types of anions forming the ion pair may be one type or two or more types.

[0078] Therefore, the ion pair described here includes not only an electrically bonded compound between one type of cation and one type of anion, but also an electrically bonded compound between two or more types of cations and two or more types of anions (so-called ionic bonded compounds), including polymers such as tetramers.

[0079] In particular, unlike neutral molecules, which are static components that are electrically stable in an electrolyte solution, ion pairs are dynamic components that alternately form (assemble) and disappear (disperse) over time in the electrolyte solution. As a result, the analysis device 100 can investigate the physical properties of not only neutral molecules but also ion pairs by analyzing the electrolyte solution using the calculation unit 10, measurement unit 20, and comparison unit 30.

[0080] Although it has been possible to investigate the physical properties of neutral molecules, it has been extremely difficult to investigate the physical properties of ion pairs. Therefore, analysis of electrolytes using the analysis device 100 is extremely important in that it has made it possible to investigate the physical properties of ion pairs, which was previously difficult.

[0081] <1-2. Analysis Method> Next, a description will be given of an analysis method using analysis device 100. The analysis method described here is the so-called operation of analysis device 100 (analysis procedure).

[0082] For ease of understanding, the following description will be given by way of example in which the electrolyte solution contains two or more types of constituent components C (plurality of neutral molecules m and plurality of ion pairs x).

[0083] [Calculation procedure of calculation unit] When the analysis device 100 analyzes an electrolyte solution, first, the calculation unit 10 performs MD calculations on the electrolyte solution according to the procedure described below, thereby calculating the individual calculated DRS signal S1, the calculated DRS signal S2, and the physical property value P.

[0084] (MD Calculation) Specifically, first, an MD calculation for the electrolyte is performed.

[0085] In this case, MD calculations are performed using MD calculation software by setting two or more types of constituent components C that are known to be contained in the electrolyte solution. This MD calculation calculates the behavior over time of a series of atoms that make up each constituent component C.

[0086] In addition, when the two or more types of constituent components C contained in the electrolytic solution are unknown, two or more types of constituent components C that are assumed to be contained in the electrolytic solution may be set.

[0087] The MD calculation method (including the type of force field) is not particularly limited as long as the software is capable of executing the MD calculation, as described above. In this case, the conditions for the MD calculation can be set arbitrarily.

[0088] Next, in order to calculate the individual calculation DRS signal S1, the calculation process described below is performed based on the calculation result of the MD calculation.

[0089] (Calculation of Total Electric Dipole Moment) Specifically, the total electric dipole moment of each constituent component C is calculated.

[0090] In this case, information about the coordinates and charge of each atom at each time is read based on the trajectory included in the calculation result of the MD calculation. By doing so, the calculation formula expressed by Equation (1) is used to calculate the N included in the calculation cell of the MD calculation. m i (i = 1, 2, 3, ..., N m ) calculate the individual electric dipole moment of the neutral molecule m.

[0091] (d m,i is the individual electric dipole moment of the neutral molecule m. j is the index of the atom contained in the i-th neutral molecule m. q j is the charge of atom j. m,ij is the coordinate of atom j. m,ijis the relative coordinate of the i-th molecule with respect to the center of gravity.)

[0092] Next, the total electric dipole moment of the neutral molecule m is calculated using the calculation formula expressed by equation (2).

[0093] (M m is the total electric dipole moment of the neutral molecule m.)

[0094] Finally, the total electric dipole moment of the ion pair x is calculated using the calculation formula (3): x,i The calculation procedure is the same as the calculation procedure using equation (1).

[0095]

[0096] Here, when calculating the total electric dipole moment of an ion pair x (CIP), the distance r between the center of gravity W of the cation and the center of gravity X of the anion is W-X The electric dipole moment is calculated only when the condition that the distance between the electrodes is equal to or less than a predetermined distance is satisfied. For example, when the electrolyte salt is lithium hexafluorophosphate (LiPF 6 ), then the distance r W-X The electric dipole moment is calculated only when the condition that is 0.425 nm (=4.25 Å) or less is satisfied.

[0097] Note that the threshold value of "0.425 nm" (distance r W-X ) is a battery whose electrolyte salt is lithium hexafluorophosphate (LiPF 6 ), the radial distribution function of the phosphorus atom (P) centered on the lithium atom shows the first dip, and this value is appropriately determined depending on the type of cation and the type of anion. Note that, although the ion pair x when focusing on the closest position between the lithium atom and the anion is defined as a CIP, similar analysis can be performed for ion pairs x other than CIP by determining the second nearest position based on the radial distribution function.

[0098] (Calculation of Time Correlation Function) Next, the time correlation function of each component C is calculated based on the total dipole moment.

[0099] In this case, the time correlation function of the total electric dipole moment for the neutral molecule m is calculated using the calculation formula expressed by equation (4).

[0100] (C m,total (t) is the time correlation function of the total electric dipole moment for the neutral molecule m.

[0101] Furthermore, the time correlation function of the total electric dipole moment for the ion pair x is calculated using the calculation formula expressed by equation (5).

[0102] (C x,total (t) is the time correlation function of the total electric dipole moment for the ion pair x.

[0103] (Approximation of Time Correlation Function) Next, the time correlation function is approximated to an exponential function.

[0104] In this case, the time correlation function of the neutral molecule m is fitted using the least squares method, which removes noise (fluctuation error) from the time correlation function, thereby suppressing the influence of calculation errors and the like in the Fourier transform described below.

[0105] Furthermore, the time correlation function of the ion pair x is fitted using the least squares method, which removes noise (fluctuation errors) from the time correlation function, thereby suppressing the influence of calculation errors and the like in the Fourier transform described below, as described above.

[0106] (Fourier Transform of Time Correlation Function, Calculation of Individual Calculated DRS Signal S1, and Calculation of Calculated DRS Signal S2) Next, the approximation result of the time correlation function is Fourier transformed to calculate the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0107] Specifically, the relaxation strength Δε of the neutral molecule m is calculated using the calculation formula (8). m Calculate the relaxation strength Δε m By performing a Fourier transform on the approximation result of the time correlation function for the neutral molecule m using equation (6), the real part of the permittivity is calculated using equation (7), and the imaginary part of the permittivity is calculated using equation (8). As a result, an individually calculated DRS signal S1 including the real part and imaginary part of the permittivity for the neutral molecule m is calculated.

[0108] (ε' m (ω) is the real part of the dielectric constant of the neutral molecule m, where ω = 2πν.

[0109] (ε m (ω) is the imaginary part of the dielectric constant of the neutral molecule m, where ω = 2πν.

[0110] (Δε m is the relaxation strength of the neutral molecule m. V is the volume. K B is the Boltzmann constant. T is the temperature.)

[0111] In addition, the relaxation strength Δε of the ion pair x is calculated using the calculation formula (11). x Calculate the relaxation strength Δε x By performing a Fourier transform on the approximation result of the time correlation function for the ion pair x using the above formula, the real part of the permittivity is calculated using the formula (9), and the imaginary part of the permittivity is calculated using the formula (10). As a result, an individually calculated DRS signal S1 including the real part of the permittivity and the imaginary part of the permittivity is calculated for the ion pair x.

[0112] (ε' x (ω) is the real part of the permittivity of the ion pair x, where ω = 2πν.

[0113] (ε x (ω) is the imaginary part of the permittivity of the ion pair x, where ω = 2πν.

[0114] (Δε x is the relaxation strength of ion pair x. V is the volume. K B is the Boltzmann constant. T is the temperature. A is the scaling factor.)

[0115] As shown in equation (11), the relaxation strength Δε of the ion pair x x When calculating the total electric dipole moment of ion pair x, a scaling factor A is used. If the total electric dipole moment of ion pair x is calculated without considering the influence of the solvent present around the ion pair x, the accuracy of the finally calculated individually calculated DRS signal S1 may be reduced due to errors. Therefore, an appropriate scaling factor A is used to effectively introduce the shielding effect of the solvent around the ion pair x. The value of the scaling factor A is not particularly limited, but an example is 0.25.

[0116] Therefore, the calculated DRS signal S2 of the electrolyte is calculated by adding the individual calculated DRS signal S1 of the neutral molecule m and the individual calculated DRS signal S1 of the ion pair x.

[0117] (Calculation of Physical Property Values) Subsequently, a physical property value P specific to each constituent component C is calculated based on the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0118] Here, the physical property value P is the relaxation strength Δε m , Δε x , characteristic time τ m , τ x , concentration n m , n x , static permittivity ε m sta , ε x sta An example will be given of calculating the salt dissociation degree α.

[0119] Relaxation strength Δε of neutral molecule m m When calculating the relaxation strength Δε using the formula (8) as described above, m Calculate the relaxation strength Δε of the ion pair x. x When calculating the relaxation strength Δε using the formula (11) as described above, x Calculate.

[0120] Characteristic time τ of neutral molecule m m When calculating the frequency of the peak position of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the neutral molecule m, the frequency of the peak position of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the neutral molecule m is set to a specific frequency v m By using the calculation formula (12), the characteristic time τ m Calculate this characteristic time τ m is the specific frequency ν m is the reciprocal of

[0121]

[0122] Also, the characteristic time τ of the ion pair x x When calculating the frequency of the peak position of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the ion pair x, the frequency of the peak position of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the ion pair x is set to a specific frequency v x By using the calculation formula (13), the characteristic time τ x Calculate this characteristic time τ x is the specific frequency ν x is the reciprocal of

[0123]

[0124] Concentration n of neutral molecules m m When calculating, the number N of neutral molecules m included in the calculation cell of the MD calculation is m and the volume V of the calculation cell of the MD calculation, n m = N m Using the formula / V, the concentration n m Calculate.

[0125] Also, the concentration of ion pair x is n x When calculating, the average number of ion pairs x included in the calculation cell of the MD calculation is <N x > and the volume V of the calculation cell of the MD calculation, x =<N x Using the formula: x Calculate.

[0126] When calculating the salt dissociation degree α, the total number of cations N included in the calculation cell of the MD calculation is cat and the average number of cations that are not close to the anion among the cations is <N cat,free Based on the above, α=<N cat,free> / N cat The salt dissociation degree α is calculated using the following formula.

[0127] Static dielectric constant ε of neutral molecule m m sta When calculating the permittivity, the permittivity is calculated as ω → 0 (or ν → 0) based on the individual calculated DRS signal S1 (permittivity real part) for the neutral molecule m, and the calculated value of the permittivity is converted into the static permittivity ε m sta Let's say.

[0128] Also, the static dielectric constant ε of the ion pair x x sta When calculating the dielectric constant, the dielectric constant is calculated as ω → 0 (or ν → 0) based on the individually calculated DRS signal S1 (dielectric constant real part) for the ion pair x, and the calculated value of the dielectric constant is converted into the static dielectric constant ε x sta Let's say.

[0129] (Output of Data D1) Finally, the data D1 is output to the comparison section 30. Details regarding the data D1 are as described above.

[0130] [Measurement Procedure of Measurement Unit] Next, in the measurement unit 20, the electrolyte solution is analyzed using dielectric relaxation spectroscopy according to the procedure described below, thereby measuring the measured DRS signal S3 of the electrolyte solution.

[0131] (Measurement of Measured DRS Signal S3) Specifically, first, based on the analysis result of the electrolyte solution using dielectric relaxation spectroscopy, the measured DRS signal S3 for the electrolyte solution is measured.

[0132] (Correction of Measured DRS Signal S3) Next, the measured DRS signal S3 is corrected. In this case, as described above, the measured DRS signal S3 is fitted using a Debye relaxation function, thereby removing errors caused by the ionic conductivity of the electrolyte from the measured DRS signal S3.

[0133] (Output of Data S2) Finally, data D2 is output to the comparison section 30. Details regarding data D2 are as described above.

[0134] [Comparison Procedure of the Comparator] Finally, in the comparator 30, the calculated DRS signal S2 and the measured DRS signal S3 are compared with each other according to the procedure described below, and the calculated DRS signal S2 and the measured DRS signal S3 are confirmed to be qualitatively consistent with each other, whereby the measured DRS signal S3 is attributed using the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2.

[0135] (Comparison of calculated DRS signal S2 and measured DRS signal S3) Specifically, first, the calculated DRS signal S2 and the measured DRS signal S3 are compared with each other to confirm whether the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other.

[0136] In this case, the spectral shape of the calculated DRS signal S2 and the spectral shape of the measured DRS signal S3 are compared with each other from the viewpoint of whether or not they qualitatively match each other.

[0137] An example of comparison items when comparing the spectral shapes of both are as follows: (1) The frequency value at the peak position of the imaginary part of the dielectric constant (2) The intensity value at the peak position of the imaginary part of the dielectric constant (3) The static dielectric constant (4) The tendency of the series of values ​​shown in (1) to (3) to change when the concentration of the electrolyte is changed

[0138] (Assignment of measured DRS signal S3 using individually calculated DRS signal S1) Next, the individually calculated DRS signal S1 is used to assign the measured DRS signal S3.

[0139] In this case, when it is confirmed that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match each other, it is determined that the reliability of the calculated DRS signal S2 is guaranteed, and therefore the measured DRS signal S3 can be attributed using the individually calculated DRS signal S1.

[0140] In this case, the reliability of the calculated DRS signal S2 is ensured, and therefore the reliability of the multiple individual calculated DRS signals S1 that make up the calculated DRS signal S2 is also ensured. Therefore, even if the measured DRS signal S3 could be decomposed into each component C, it would not be technically or logically (in terms of accuracy) problem to assume that multiple individual calculated DRS signals S1 would be obtained.

[0141] (Output of Data D3) Finally, data D3 is output to the outside. Details regarding data D3 are as described above.

[0142] Analysis device 100 may store data D3 internally without outputting data D3 externally. Of course, analysis device 100 may store data D3 internally and output data D3 externally.

[0143] <1-3. Actions and Effects> According to the analysis device 100 of the first embodiment, the analysis device 100 includes a calculation unit 10, a measurement unit 20, and a comparison unit 30. The calculation unit 10 calculates an individual calculated DRS signal S1 and a calculated DRS signal S2 using MD calculations related to the electrolyte solution, and also calculates a physical property value P. The measurement unit 20 measures a measured DRS signal S3 related to the electrolyte solution by analyzing the electrolyte solution using dielectric relaxation spectroscopy. The comparison unit 30 compares the calculated DRS signal S2 and the measured DRS signal S3 with each other, thereby attributing the measured DRS signal S3 using the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2.

[0144] In particular, the calculation unit 10 calculates the individually calculated DRS signal S1 using calculation procedure 1. Specifically, the calculation unit 10 calculates the total electric dipole moment of the component C, calculates the time correlation function of the component C, approximates the time correlation function to an exponential function, and performs a Fourier transform on the approximation result of the time correlation function, thereby calculating the individually calculated DRS signal S1 of the component C.

[0145] In this case, the comparison unit 30 compares the calculated DRS signal S2 of the electrolyte calculated by the calculation unit 10 using MD calculation with the measured DRS signal S3 of the electrolyte measured by the measurement unit 20 using dielectric relaxation spectroscopy. When it is confirmed that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively match, the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3 is ensured, and the reliability of the multiple individual calculated DRS signals S1 constituting the calculated DRS signal S2 is also ensured. Therefore, it becomes possible to attribute the measured DRS signal S3 using the individual calculated DRS signals S1, which are components of the calculated DRS signal S2.

[0146] As a result, not only are the physical properties of the neutral molecule m determined based on the individual calculated DRS signal S1 for that neutral molecule m, but also the physical properties of the ion pair x determined based on the individual calculated DRS signal S1 for that ion pair x. Therefore, by taking into account not only the physical properties of the neutral molecule m but also the physical properties of the ion pair x, it becomes possible to freely design the configuration of an electrolyte solution having desired performance in terms of ion transportability, etc.

[0147] From these facts, when designing the composition of a new electrolyte solution, the composition of the electrolyte solution having the desired performance can be designed as described above, without actually measuring the physical properties of the neutral molecule m and the physical properties of the ion pair x, and the physical properties of the electrolyte solution can be analyzed easily and with high accuracy.

[0148] In this case, as described above, it is particularly possible to grasp the physical properties of the ion pair, which has been difficult to do in the past. Moreover, since the physical properties of the constituent C can be grasped using only the calculated DRS signal S2 (individually calculated DRS signal S1), there is no need to prepare a calibration model such as a calibration curve in advance, and there is no need to normalize the intensity of the DRS signal. Therefore, the detailed physical properties of the electrolyte can be more easily analyzed, and the composition of the electrolyte having the desired performance can be designed with higher accuracy.

[0149] In particular, if the electrolyte solution contains a solvent and an electrolyte salt, and component C contains one or more of neutral molecules and ion pairs, the properties of the ion pairs as well as the neutral molecules are analyzed. This allows the properties of the electrolyte solution to be analyzed with higher accuracy, resulting in greater effectiveness.

[0150] Furthermore, if the physical property value P includes one or more of the relaxation strength, characteristic time, static dielectric constant, concentration, and salt dissociation degree, various physical properties related to the electrolyte can be analyzed with higher accuracy, thereby achieving greater effects.

[0151] Furthermore, in order for the calculation unit 10 to calculate the individually calculated DRS signal S1, it calculates the total electric dipole moment of the component C, calculates the time correlation function of the component C, approximates the time correlation function to an exponential function, and Fourier transforms the time correlation function to calculate the individually calculated DRS signal S1. This allows the individually calculated DRS signal S1 of the component C to be calculated with high accuracy using a calculation process, thereby achieving a greater effect.

[0152] Furthermore, if the constituent C contains two or more types of neutral molecules and ion pairs, and the calculation unit 10 calculates the individual calculated DRS signals S1 for each of the two or more types of constituent C, and then calculates the calculated DRS signal S2 by adding up these individual calculated DRS signals S1, then the calculated DRS signal S2 can be calculated even when there are two or more types of constituent C, thereby achieving a greater effect.

[0153] Furthermore, the measurement unit 20 corrects the measured DRS signal S3 by removing errors caused by the ionic conductivity of the electrolyte, and the comparison unit 30 compares the calculated DRS signal S2 with the corrected result of the measured DRS signal S3. This improves the accuracy of the comparison, thereby improving the accuracy of the attribution. Therefore, the physical properties of the electrolyte can be analyzed with higher accuracy, resulting in a greater effect.

[0154] In addition, according to the analysis method of the first embodiment, the individual calculated DRS signal S1 and the calculated DRS signal S2 are calculated using MD calculations for the electrolyte solution, the measured DRS signal S3 for the electrolyte solution is measured using dielectric relaxation spectroscopy, the calculated DRS signal S2 and the measured DRS signal S3 are compared with each other, the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2, is used to attribute the measured DRS signal S3, and the physical property value P for the electrolyte solution is calculated. Therefore, for the reasons described above, the physical properties of the electrolyte solution can be analyzed easily and with high accuracy.

[0155] Other functions and effects of this analysis method are similar to those of analysis device 100.

[0156] 2. Analysis Device and Analysis Method (Second Embodiment) Next, an analysis device and an analysis method according to a second embodiment of the present technology will be described.

[0157] As will be described below, the analysis device 100 of the second embodiment has a configuration similar to that of the analysis device 100 of the first embodiment, except that the calculation procedure of the individually calculated DRS signal S1 by the calculation unit 10 is different. Note that the details of the electrolyte solution, the constituent component C, and the physical property value P are as described above.

[0158] <2-1. Analysis Device> Here, the configuration of the analysis device 100 of the second embodiment will be described with reference to FIG. 1 already described.

[0159] The configuration of the analysis device 100 in the second embodiment is similar to the configuration of the analysis device 100 in the first embodiment, except for the points described below.

[0160] Here, the calculation unit 10 sequentially performs the calculation processes described below to calculate the individual calculated DRS signal S1. That is, the calculation unit 10 calculates the individual electric dipole moment of the component C based on the calculation results of the MD calculation. The calculation unit 10 also calculates the time correlation function of the component C based on the individual electric dipole moment, and then calculates the rotational correlation time of the component C by approximating the time correlation function to an exponential function. Furthermore, the calculation unit 10 calculates the individual calculated DRS signal S1 of the component C based on the rotational correlation time.

[0161] Hereinafter, the calculation procedure for the individually calculated DRS signal S1 in the second embodiment will be referred to as “calculation procedure 2.” As a result, the configuration of the analysis device 100 in the second embodiment is the same as the configuration of the analysis device 100 in the first embodiment, except that the calculation unit 10 uses calculation procedure 2 instead of calculation procedure 1 to calculate the individually calculated DRS signal S1.

[0162] The details of the functions of calculation unit 10 described here will be specifically explained when explaining the operation (analysis procedure) of analysis device 100 described later.

[0163] <2-2. Analysis Method> A description will be given of an analysis method using the analysis device 100 of the second embodiment. The analysis method described here is the operation (analysis procedure) of the analysis device 100, as described above.

[0164] The procedure of the analysis method in the second embodiment is the same as the procedure of the analysis method in the first embodiment, except for the points described below.

[0165] To calculate the individual calculation DRS signal S1, the calculation unit 10 performs the calculation process described below based on the results of the MD calculation.

[0166] (Calculation of Individual Electric Dipole Moment) Specifically, first, the individual electric dipole moment of each constituent component C is calculated.

[0167] In this case, the coordinates and charges of each atom at each time are read based on the trajectory included in the calculation result of the MD calculation. m The individual electric dipole moment of the i-th neutral molecule m among the neutral molecules m is calculated at each time, and N x The individual electric dipole moment of the ith ion pair x among the ion pairs x is calculated at each time.

[0168] (Calculation of Rotational Correlation Function) Next, based on the individual electric dipole moment, the rotational correlation function of each component C is calculated. This rotational correlation function decays exponentially with respect to time.

[0169] In this case, the rotational correlation function of the neutral molecule m is calculated by normalizing the individual dipole moment of the neutral molecule m with respect to a unit vector whose length is 1 using the calculation formula expressed by Equation (14).

[0170] (N m is the number of neutral molecules m.)

[0171] Furthermore, by normalizing the individual dipole moments of the ion pair x, the rotational correlation function of the ion pair x is calculated using the formula (15) for a unit vector with a length of 1.

[0172] (N pair is the number of ion pairs whose individual dipole moments reach a finite value at least once in the trajectory of the MD calculation.)

[0173] (Approximation of Rotational Correlation Function and Calculation of Rotational Correlation Time) Next, the rotational correlation function is approximated to an exponential function to calculate the rotational correlation time of each component C.

[0174] In this case, the rotational correlation time of neutral molecule m is calculated by fitting the rotational correlation function of the neutral molecule m using the least squares method, and the rotational correlation time of ion pair x is calculated by fitting the rotational correlation function of the ion pair x using the least squares method.

[0175] As a result, the characteristic time of neutral molecule m is calculated using the formula (16), and the characteristic frequency of neutral molecule m is calculated using the formula (17). In addition, the characteristic time of ion pair x is calculated using the formula (18), and the characteristic frequency of ion pair x is calculated using the formula (19).

[0176] (τ m is the characteristic time of the neutral molecule m.)

[0177] (ν m is the characteristic frequency of the neutral molecule m.

[0178] (τ x is the characteristic time of ion pair x.)

[0179] (ν x is the characteristic frequency of ion pair x.)

[0180] (Calculation of Individual Calculated DRS Signal S1 and Calculation of Calculated DRS Signal S2) Subsequently, the individual calculated DRS signal S1 and the calculated DRS signal S2 are calculated based on the rotation correlation time.

[0181] Specifically, when calculating the individual calculated DRS signal S1 of the neutral molecule m, the real part of the permittivity is calculated by assuming Debye relaxation expressed by Equation (20) as the relaxation form for restoring the DRS signal, and the imaginary part of the permittivity is calculated by assuming Debye relaxation expressed by Equation (21) as the relaxation form for restoring the DRS signal. m The calculation method of is as described above. As a result, an individual calculated DRS signal S1 including the real part of the permittivity and the imaginary part of the permittivity is calculated for the neutral molecule m.

[0182] (ε' m (ω) is the real part of the dielectric constant, where ω = 2πν.

[0183] (ε m (ω) is the real part of the dielectric constant, where ω = 2πν.

[0184] Furthermore, when calculating the individual DRS signal S1 of the ion pair x, the real part of the dielectric constant is calculated by assuming Debye relaxation expressed by Equation (22) as the relaxation form, and the imaginary part of the dielectric constant is calculated by assuming Debye relaxation expressed by Equation (23) as the relaxation form. x The calculation method for is as described above. As a result, an individual calculated DRS signal S1 including the real part of the dielectric constant and the imaginary part of the dielectric constant is calculated for the ion pair x.

[0185] (ε' x (ω) is the real part of the dielectric constant, where ω = 2πν.

[0186] (ε x (ω) is the real part of the dielectric constant, where ω = 2πν.

[0187] Therefore, the calculated DRS signal S2 of the electrolyte is calculated by adding the individual calculated DRS signal S1 of the neutral molecule m and the individual calculated DRS signal S1 of the ion pair x.

[0188] <2-3. Actions and Effects> According to the analysis device 100 of the second embodiment, the analysis device 100 comprises the calculation unit 10, the measurement unit 20, and the comparison unit 30 described above.

[0189] In particular, the calculation unit 10 calculates the individual calculated DRS signal S1 using calculation procedure 2 instead of calculation procedure 1. Specifically, the calculation unit 10 calculates the individual electric dipole moment of the component C, calculates the rotational correlation function of the component C, approximates the rotational correlation function to an exponential function, calculates the rotational correlation time of the component C, and calculates the individual calculated DRS signal S1 of the component C.

[0190] In this case, for the same reasons as those described in relation to the first embodiment, the reliability of the calculated DRS signal S2 (individually calculated DRS signal S1) relative to the measured DRS signal S3 is guaranteed, and therefore not only the physical properties of the neutral molecule m but also the physical properties of the ion pair x are grasped. As a result, by taking into account not only the physical properties of the neutral molecule m but also the physical properties of the ion pair x, it becomes possible to freely design the configuration of an electrolyte solution having desired performance in terms of ion transportability, etc.

[0191] From these facts, when designing the configuration of a new electrolyte solution, the configuration of the electrolyte solution having desired performance can be designed without actually measuring the physical properties of the neutral molecule m and the physical properties of the ion pair x, and therefore, similar to the first embodiment, the physical properties of the electrolyte solution can be analyzed easily and with high accuracy.

[0192] In addition, according to the analysis method of the second embodiment, the individual calculated DRS signal S1 and the calculated DRS signal S2 are calculated using MD calculations for the electrolyte solution, the measured DRS signal S3 for the electrolyte solution is measured using dielectric relaxation spectroscopy, and the calculated DRS signal S2 and the measured DRS signal S3 are compared with each other, whereby the measured DRS signal S3 is assigned using the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2, and the physical property value P for the electrolyte solution is calculated. Therefore, for the reasons described above, the physical properties of the electrolyte solution can be analyzed easily and with high accuracy.

[0193] Other functions and effects of the analysis device 100 and the analysis method in the second embodiment are similar to those of the analysis device 100 and the analysis method in the first embodiment.

[0194] 3. Modifications The configuration of the above-described analysis device 100 can be modified as needed, and the procedure of the above-described analysis method can be modified as needed. Note that any two or more of the series of modifications described below may be combined with each other.

[0195] [Modification 1] In each of the first and second embodiments, calculation processing is performed using the calculation unit 10, and then measurement processing is performed using the actual measurement unit 20. However, measurement processing using the actual measurement unit 20 may be performed first, and then calculation processing using the calculation unit 10. Even in this case, comparison processing can be performed in the comparison unit 30, and therefore similar effects can be obtained.

[0196] [Modification 2] FIG. 2 shows a block configuration of an analysis device 200 in Modification 2, and corresponds to FIG.

[0197] 1, analysis device 100 includes calculation unit 10, measurement unit 20, and comparison unit 30. However, analysis device 200 may include only calculation unit 10 without measurement unit 20 and comparison unit 30, as shown in FIG.

[0198] The configuration of analysis device 200 is similar to that of analysis device 100, except that analysis device 200 does not include measurement section 20 and comparison section 30, and data D1 is output to the outside.

[0199] Specifically, if an electrolyte solution having a given composition has not yet been analyzed using the analysis device 100, a comparison between the calculated DRS signal S2 and the measured DRS signal S3 has not yet been performed, and the attribution of the measured DRS signal S3 using the individual calculated DRS signal S1 has not yet been performed. Therefore, the reliability of the individual calculated DRS signal S1 and the calculated DRS signal S2 has not yet been guaranteed. In this case, in order to guarantee the reliability of the calculated DRS signal S2, it is necessary to perform not only the calculation processing of the calculated DRS signal S2 by the calculation unit 10, but also the measurement processing of the measured DRS signal S3 by the measurement unit 20 and the comparison processing of the calculated DRS signal S2 and the measured DRS signal S3 by the comparison unit 30. Therefore, as shown in FIG. 1, the analysis device 100 must include not only the calculation unit 10 but also the measurement unit 20 and the comparison unit 30.

[0200] In contrast, if an electrolyte solution having an arbitrary configuration has already been analyzed using the analysis device 100, the calculated DRS signal S2 has already been compared with the measured DRS signal S3, and the measured DRS signal S3 has already been attributed using the individual calculated DRS signal S1, so the reliability of each of the individual calculated DRS signal S1 and the calculated DRS signal S2 has already been ensured. In this case, there is no need to ensure the reliability of the calculated DRS signal S2 again, so only the calculation process of the calculated DRS signal S2 by the calculation unit 10 is required, while the measurement process of the measured DRS signal S3 by the measurement unit 20 and the comparison process of the calculated DRS signal S2 with the measured DRS signal S3 by the comparison unit 30 are not required. Therefore, since the calculated DRS signal S2 (individually calculated DRS signal S1), whose reliability is already guaranteed, can be used as is, the analysis device 200 may have only the calculation unit 10, as shown in Figure 2, without having the measurement unit 20 and the comparison unit 30.

[0201] In other words, if the reliability of the calculated DRS signal S2 is already guaranteed, instead of the analysis device 100 which is equipped with the calculation unit 10, the measurement unit 20 and the comparison unit 30, an analysis device 200 which does not have the measurement unit 20 and the comparison unit 30 but only has the calculation unit 10 may be used.

[0202] In this analysis device 200, the calculation unit 10 may calculate the individually calculated DRS signal S1 using calculation procedure 1 described in the first embodiment, or the calculation unit 10 may calculate the individually calculated DRS signal S1 using calculation procedure 2 described in the second embodiment.

[0203] Specifically, when calculation procedure 1 is used, the calculation unit 10 may perform an MD calculation, calculate a total electric dipole moment, calculate a time correlation function, approximate the time correlation function to an exponential function, perform a Fourier transform on the approximation result of the time correlation function, calculate an individual calculated DRS signal S1 and a calculated DRS signal S2, calculate a physical property value P, and output data D1 to the outside.

[0204] Furthermore, when calculation procedure 2 is used, the calculation unit 10 may perform an MD calculation, calculate an individual electric dipole moment, calculate a rotational correlation function, approximate the rotational correlation function to an exponential function, calculate a rotational correlation time, calculate an individual calculated DRS signal S1 and a calculated DRS signal S2, calculate a physical property value P, and output data D1.

[0205] Even in this case, the reliability of the calculated DRS signal S2 (individually calculated DRS signal S1) is guaranteed, and for the reasons explained in the first and second embodiments, the physical properties of the electrolyte can be analyzed easily and with high accuracy.

[0206] [Variation 3] In the first embodiment, the calculation unit 10 used calculation procedure 1 to calculate the individually calculated DRS signal S1, and in the second embodiment, the calculation unit 10 used calculation procedure 2 to calculate the individually calculated DRS signal S1.

[0207] However, the calculation unit 10 may use both calculation procedures 1 and 2 to calculate the individually calculated DRS signal S1. In this case, by comparing the individually calculated DRS signal S1 calculated by calculation procedure 1 with the individually calculated DRS signal S1 calculated by calculation procedure 2, the individually calculated DRS signal S1 is finally determined, and therefore, the calculation accuracy of the individually calculated DRS signal S1 is further improved, thereby achieving a greater effect.

[0208] When only one of the calculation procedures 1 and 2 is used, it is preferable to use the calculation procedure 1.

[0209] However, when only calculation procedure 1 is used, the reproducibility of the individually calculated DRS signal S1 may be insufficient due to insufficient statistics depending on factors such as cell size and calculation time. Therefore, in order to sufficiently increase the calculation accuracy of the individually calculated DRS signal S1 and thereby sufficiently increase the reliability of the individually calculated DRS signal S1, it is preferable to use both calculation procedures 1 and 2, as described in Modification 2.

[0210] [Modification 4] In the second embodiment, the Debye relaxation is assumed as the relaxation mode when the calculation unit 10 calculates the individually calculated DRS signal S1. However, the relaxation mode is not particularly limited and can be changed arbitrarily.

[0211] Specifically, the relaxation mode may be Cole-Davidson relaxation or the like in addition to Debye relaxation. When Cole-Davidson relaxation is assumed as the relaxation mode, the above-mentioned characteristic time τ m , τ x and relaxation strength Δε m , Δε x However, it should be noted that additional parameters are required. However, the above-mentioned additional parameters are identified by applying the least squares method to each of the calculated DRS signal S2 (individually calculated DRS signal S1) and the measured DRS signal S3. Even when Cole-Davidson relaxation is used as the relaxation form, it is possible to attribute the measured DRS signal S3 using the individually calculated DRS signal S1, just as in the case where Debye relaxation is assumed as the relaxation form.

[0212] Even in this case, the reliability of the calculated DRS signal S2 (individually calculated DRS signal S1) is guaranteed, and the measured DRS signal S3 is assigned using the individually calculated DRS signal S1, so the physical properties of the electrolyte can be analyzed easily and with high accuracy.

[0213] Note that the modified example 2 described here is not limited to the second embodiment, and may be applied to both modified examples 2 and 3. In this case, the same effects can be obtained.

[0214] [Variation 5] In the first embodiment, as shown in FIG. 1, the analysis device 100 includes the comparison unit 30, and as described above, the comparison unit 30 performs a comparison process between the calculated DRS signal S2 and the measured DRS signal S3 using image analysis processing.

[0215] However, although not specifically illustrated here, the analysis device 100 may not necessarily include the comparison unit 30. In this case, instead of the comparison unit 30, a display device that displays the calculated DRS signal S2 and the measured DRS signal S3 may be used, allowing the user of the analysis device 100 to visually and artificially compare the calculated DRS signal S2 with the measured DRS signal S3. Even in this case, the calculated DRS signal S2 can be used to attribute the measured DRS signal S3, thereby achieving the same effect.

[0216] An embodiment of the present technology will be described.

[0217] Example 1 As will be described below, the electrolyte solution was analyzed using the analysis device 100 (analysis method) described in the first embodiment to examine the physical properties of the electrolyte solution. The electrolyte solution used here contained propylene carbonate (PC) as a solvent and lithium hexafluorophosphate (LiPF ) as an electrolyte salt. 6 )

[0218] [Configuration of Analysis Apparatus] The configuration of analysis apparatus 100 is as described below.

[0219] (Configuration of the Calculation Unit) WMI-MD software capable of executing MD calculations was used as the calculation unit 10. This software uses APPLE&P as the force field.

[0220] (Configuration of Measurement Unit) A vector network analyzer (VNA N5234A manufactured by Keysight), a microwave coaxial cable (MWX221 manufactured by Junflon), and an open-ended probe (85070E-020 manufactured by Keysight) were used as the dielectric spectroscopy unit of the measurement unit 20. As described above, this open-ended probe was connected to the vector network analyzer via the microwave coaxial cable.

[0221] The measurement method used by the measurement unit 20 was the reflection transmission method (S-parameter method) using reflection coefficients S11 and S22. The reflection coefficient S11 is the reflection coefficient of the first port of the vector network analyzer, and the reflection coefficient S22 is the reflection coefficient of the second port of the vector network analyzer.

[0222] The software used to calculate the complex dielectric constant (measured DRS signal S3) based on the reflection coefficient was the software included with the above-mentioned vector network analyzer.

[0223] Before measuring the actual DRS signal S3, the measurement cell was opened and filled with pure solvents with known dielectric constants, such as water, benzonitrile, and N,N-dimethylacetamide, to perform calibration.

[0224] When measuring the actual DRS signal S3, the electrolyte was introduced into the measurement cell using a syringe, and the tip of the open-ended probe was brought into contact with the electrolyte. In this case, care was taken to prevent air from being included in the electrolyte, and the amount (volume) of the electrolyte was kept constant during measurement.

[0225] As the correction section of the measurement section 20, spreadsheet software (Excel) manufactured by Microsoft Corporation was used.

[0226] (Configuration of the Comparison Unit) As software capable of performing comparison processing using image analysis processing, a program capable of qualitatively comparing the calculated DRS signal S2 and the measured DRS signal S3 based on the series of comparison items described above was used as the comparison unit 30. This program was an original program created using Python.

[0227] [Analysis of Electrolyte Solution Using Analysis Device] According to the procedure described below, the electrolyte solution was analyzed using analysis device 100. Each of Figs. 3 to 8 shows the analysis results of the electrolyte solution using analysis device 100.

[0228] Specifically, FIG. 3 shows the calculation results of the time correlation function (the horizontal axis is time (ns), and the vertical axis is the time correlation function), and FIG. 4 shows the approximation results of the time correlation function (the horizontal axis is time (ns), and the vertical axis is the time correlation function).

[0229] 5 shows the calculation results of the individual calculated DRS signal S1 (permittivity real part) and the calculated DRS signal S2 (permittivity real part) (horizontal axis: frequency v (GHz), vertical axis: real part of permittivity). FIG. 6 shows the calculation results of the individual calculated DRS signal S1 (permittivity imaginary part) and the measured DRS signal S3 (permittivity imaginary part) (horizontal axis: frequency v (GHz), vertical axis: imaginary part of permittivity). FIG. 7 shows the calculation results of the calculated DRS signal S2 (permittivity real part and permittivity imaginary part) (horizontal axis: frequency v (GHz), vertical axis: real part and imaginary part of permittivity).

[0230] FIG. 8 shows the measurement results of the measured DRS signal S3 (the real part and imaginary part of the dielectric constant) (the horizontal axis is the frequency ν (GHz), and the vertical axis is the real part and imaginary part of the dielectric constant).

[0231] (Calculation of individual calculated DRS signal S1 and calculation of calculated DRS signal S2) When analyzing an electrolyte solution using the analysis device 100, first, as described below, the calculation unit 10 calculates the individual calculated DRS signal S1 using calculation procedure 1, and then calculates the calculated DRS signal S2.

[0232] Specifically, first, the composition of the electrolyte was set in order to perform MD calculations for the electrolyte. In this case, as described above, PC was set as the solvent and LiPF as the electrolyte salt. 6 As a result, the neutral molecule m, PC(C 4 H 6 O 3 ) and ion pair x CIP (Li + PF6 - ) was set.

[0233] The MD calculation conditions were a system size (number of atoms) of approximately 5,000 to 10,000 and a time step of 0.5 fs. In this case, starting from a dilute state, the equilibrium volume at room temperature and pressure was obtained in the NPT ensemble, where the number of particles, pressure, and temperature were all constant. After performing equilibrium calculations for approximately 10 ns, the main calculations were performed. Furthermore, by performing calculations for 18 ns or more in the NPT ensemble, the behavior (position, i.e., coordinates) of the series of atoms constituting each component C was obtained.

[0234] The content of electrolyte salt in the electrolyte solution (M = mol / dm 3 The concentration of the electrolyte salt was set to five types (0 M, 0.5 M, 1 M, 1.5 M, and 2 M). The content of the electrolyte salt described here is the content of the electrolyte salt relative to the solvent.

[0235] Next, based on the results of the MD calculation, the total electric dipole moment of each component C (neutral molecule m and ion pair x (CIP)) was calculated, and then the time correlation function of each component C was calculated based on the total electric dipole moment. Details of the calculation procedures for the total electric dipole moment and the time correlation function are as described above.

[0236] As a result, specifically, the calculation results of the time correlation function for the neutral molecule m (PC) among the series of constituent components C were obtained as shown in Figure 3. In Figure 3, as described above, the horizontal axis represents time (ns) and the vertical axis represents the time correlation function of PC, which is the neutral molecule m. As described above, the content of the electrolyte salt in the electrolyte solution was set to five types, and therefore Figure 3 shows the calculation results of five types of time correlation functions.

[0237] In FIG. 3, the relationship between 3A to 3E and the content of the electrolyte salt in the electrolytic solution is 3A=0M, 3B=0.5M, 3C=1M, 3D=1.5M, and 3E=2M.

[0238] Next, the time correlation function was approximated to an exponential function. In this case, the time correlation function was fitted using the least squares method. This eliminated the calculation error of the time correlation function (fluctuation error of the time correlation function), and the time correlation function was approximated. Details of the approximation procedure for the time correlation function are as described above.

[0239] As a result, the approximated result of the time correlation function for the neutral molecule m(PC) among the series of components C was obtained as shown in Fig. 4. That is, the approximated result of the time correlation function shown in Fig. 4 corresponds to the calculated result of the time correlation function shown in Fig. 3.

[0240] In FIG. 4, the relationship between 4A to 4E and the content of the electrolyte salt in the electrolytic solution is 4A=0M, 4B=0.5M, 4C=1M, 4D=1.5M, and 4E=2M.

[0241] Subsequently, the approximation result of the time correlation function was Fourier transformed to calculate the individual calculated DRS signals S1 (real part and imaginary part of the dielectric constant) of each constituent C, and then these individually calculated DRS signals S1 were added to calculate the calculated DRS signal S2 (real part and imaginary part of the dielectric constant) of the electrolyte solution. In this case, the value of the scaling factor A was set to 0.25.

[0242] The details of the Fourier transform procedure of the time correlation function, the calculation procedure of the individual calculated DRS signal S1, and the calculation procedure of the calculated DRS signal S2 are as described above.

[0243] As a result, as shown in FIG. 5, an individual calculated DRS signal S1 (real part of dielectric constant) for each component C (neutral molecule m (PC) and ion pair x (CIP)) was obtained. Also, as shown in FIG. 6, an individual calculated DRS signal S1 (imaginary part of dielectric constant) for each component C (neutral molecule m (PC) and ion pair x (CIP)) was obtained. In FIG. 5, as described above, the horizontal axis indicates frequency v (GHz), and the vertical axis indicates the real part of dielectric constant. In FIG. 6, as described above, the horizontal axis indicates frequency v (GHz), and the vertical axis indicates the imaginary part of dielectric constant.

[0244] Furthermore, a calculated DRS signal S2 of the electrolyte was obtained as shown in Fig. 7. In Fig. 7, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the real part and imaginary part of the dielectric constant.

[0245] As described above, in FIG. 5, in order to facilitate comparison, not only the individual calculated DRS signal S1 (real part of permittivity) but also the calculated DRS signal S2 (real part of permittivity) is shown.

[0246] 5, the relationship between 5A to 5G and the content of electrolyte salt in the electrolyte solution is 5A = 0 M, 5B to 5D = 1 M, and 5E to 5G = 2 M. Also, FIG. 5 shows 5C and 5F = the individual calculated DRS signal S1 of the neutral molecule m (PC), 5B and 5E = the individual calculated DRS signal S1 of the ion pair x (CIP), and 5A, 5D, and 5G = the calculated DRS signal S2.

[0247] In addition, as described above, in FIG. 6, in order to facilitate comparison, not only the individual calculated DRS signal S1 (imaginary part of permittivity) but also the calculated DRS signal S2 (imaginary part of permittivity) are shown.

[0248] 6, the relationship between 6A to 6G and the content of electrolyte salt in the electrolyte solution is 6A = 0 M, 6B to 6D = 1 M, and 6E to 6G = 2 M. Also, FIG. 6 shows 6C and 6F = the individual calculated DRS signal S1 of the neutral molecule m (PC), 6B and 6E = the individual calculated DRS signal S1 of the ion pair x (CIP), and 6A, 6D, and 6G = the calculated DRS signal S2.

[0249] 7, in order to make it easier to compare the real part of the dielectric constant with the imaginary part of the dielectric constant, the real part of the dielectric constant and the imaginary part of the dielectric constant are shown together in one drawing (FIG. 7). In this case, the positional relationship between the real part of the dielectric constant and the imaginary part of the dielectric constant is adjusted as appropriate.

[0250] 7, the relationship between 7A to 7F and the content of electrolyte salt in the electrolytic solution is as follows: 7A, 7D = 0 M, 7B, 7E = 1 M, 7C, 7F = 2 M. Also, in FIG. 7, 7A to 7C = calculated DRS signal S2 (real part of dielectric constant), and 7D to 7F = calculated DRS signal S2 (imaginary part of dielectric constant).

[0251] (Calculation of Physical Property Value P) Next, in the calculation unit 10, a physical property value P specific to each constituent component C was calculated based on the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0252] Here, the physical property value P of the neutral molecule m (PC) is the relaxation strength Δε m , characteristic time τ m , concentration n m and static permittivity ε m sta The relaxation strength Δε was calculated as the physical property P of the ion pair x (CIP). x , characteristic time τ x , concentration n x and static permittivity ε x sta In addition, the salt dissociation degree α of the electrolyte was calculated. The calculation procedure for each physical property value P was as described above.

[0253] As a result, when the content of the electrolyte salt in the electrolytic solution was 1M, the physical property value P was as follows: m = 41.5, characteristic time τ m =66.5 ps, concentration n m =11.4M, static permittivity ε m sta = 41.5. For the ion pair x (CIP), the relaxation intensity Δε x = 1.0, characteristic time τ x =76.0 ps, ​​concentration n x =0.1M, static permittivity ε x sta The salt dissociation degree α of the electrolyte was 0.76.

[0254] As a result, the calculation unit 10 outputs the data D1 to the comparison unit 30. Details regarding the data D1 are as described above.

[0255] (Measurement of Measured DRS Signal S3) Next, the measured DRS signal S3 was measured in the measurement unit 20 as described below.

[0256] Specifically, first, an electrolyte solution was prepared. In this case, as described above, an electrolyte salt (LiPF ) was dissolved in a solvent (PC). 6 ) was added to the solvent, and the solvent was stirred to prepare an electrolyte solution.

[0257] The content (M) of the electrolyte salt in the electrolytic solution was set to 11 types (0 M, 0.2 M, 0.4 M, 0.6 M, 0.8 M, 1 M, 1.2 M, 1.4 M, 1.6 M, 1.8 M, and 2 M). The content of the electrolyte salt described here is the content of the electrolyte salt relative to the solvent.

[0258] Subsequently, the electrolyte solution was analyzed using dielectric relaxation spectroscopy to measure the measured DRS signal S3 of the electrolyte solution. In this case, microwaves (frequency: 200 MHz to 43.5 GHz) were irradiated onto the electrolyte solution (temperature: 25°C), and then response waves (reflected and transmitted microwave components) were received. Based on the response waves, the measured DRS signal S3 (real and imaginary parts of the dielectric constant) was calculated.

[0259] Next, the measured DRS signal S3 was corrected to remove measurement errors caused by the ionic conductivity of the electrolyte. In this case, as described above, the measured DRS signal S3 was fitted using a Debye relaxation function. As a result, measurement errors caused by motions other than rotational motion were removed from the measured DRS signal S3, and the measured DRS signal S3 was corrected.

[0260] This resulted in the measurement result of the measured DRS signal S3 shown in Fig. 8. In Fig. 8, as described above, the horizontal axis represents the frequency v (GHz), and the vertical axis represents the real part and imaginary part of the dielectric constant.

[0261] In order to facilitate comparison between the real part of the dielectric constant and the imaginary part of the dielectric constant, the real part of the dielectric constant and the imaginary part of the dielectric constant are shown together in one drawing ( FIG. 8 ). As described above, the contents of the electrolyte salt in the electrolytic solution were set to 11 types, and therefore, 11 types of real part of the dielectric constant and 11 types of imaginary part of the dielectric constant are shown in FIG.

[0262] 8, the relationship between 8A to 8K and the content of electrolyte salt in the electrolyte solution is as follows: 8A, 8L = 0 M, 8B, 8M = 0.2 M, 8C, 8N = 0.4 M, 8D, 8O = 0.6 M, 8E, 8P = 0.8 M, 8F, 8Q = 1 M, 8G, 8R = 1.2 M, 8H, 8S = 1.4 M, 8I, 8T = 1.6 M, 8J, 8U = 1.8 M, 8K, 8V = 2 M. Also, in FIG. 8, 8A to 8K = measured DRS signal S3 (real part of dielectric constant), and 8L to 8V = measured DRS signal S3 (imaginary part of dielectric constant).

[0263] Finally, the measurement unit 20 outputs the data D2 to the comparison unit 30. Details regarding the data D2 are as described above.

[0264] (Comparison of calculated DRS signal S2 with measured DRS signal S3 and attribution of measured DRS signal S3 using individual calculated DRS signal S1) Finally, as described below, the comparison unit 30 compared the calculated DRS signal S2 with the measured DRS signal S3.

[0265] Specifically, we checked whether the spectral shapes of the calculated DRS signal S2 shown in Fig. 7 and the measured DRS signal S3 shown in Fig. 8 qualitatively matched each other, and as a result, we found the following tendency.

[0266] Specifically, first, in each of the calculated DRS signal S2 and the measured DRS signal S3, when the content of electrolyte salt in the electrolyte solution increased from 0 M to 2 M, the frequency ν (so-called peak position) at which the intensity of the imaginary part of the dielectric constant was maximum decreased, and more specifically, the frequency ν decreased from approximately 5 GHz to approximately 0.5 GHz.

[0267] Second, in each of the calculated DRS signal S2 and the measured DRS signal S3, when the content of electrolyte salt in the electrolyte solution increased from 0 M to 2 M, the maximum value of the intensity of the imaginary part of the dielectric constant (so-called peak intensity) decreased; more specifically, the intensity of the imaginary part of the dielectric constant decreased from approximately 30 to approximately 12.

[0268] Third, in each of the calculated DRS signal S2 and the measured DRS signal S3, when the content of the electrolyte salt in the electrolyte solution increases from 0 M to 2 M, the static dielectric constant ε sta decreases, and more specifically the static permittivity ε sta decreased from about 60 to about 35.

[0269] These trends indicate that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively matched each other. This ensured the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3, and therefore ensured the reliability of the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2. Therefore, the measured DRS signal S3 could be attributed using the individual calculated DRS signal S1.

[0270] Finally, analysis device 100 output data D3 to the outside. Details regarding data D3 are as described above. This completes the analysis of the electrolyte solution using analysis device 100.

[0271] [Discussion] Since the reliability of the calculated DRS signal S2 for the electrolyte was ensured, the reliability of the individual calculated DRS signals S1 for each component C (neutral molecule m (PC) and ion pair x (CIP)) was also ensured. As a result, the physical properties described below were derived from the results shown in Figures 3 to 8.

[0272] First, as is clear from FIGS. 5 to 8, in the range of electrolyte salt content in the electrolyte solution from 0 M to 2 M, the spectral shape of the measured DRS signal S3 is determined mainly according to the spectral shape of the neutral molecule m(PC).

[0273] Second, as is clear from Fig. 7, the frequency ν at which the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the neutral molecule m(PC) is maximized decreases as the content of electrolyte salt in the electrolyte solution increases. This suggests that the mobility of the neutral molecule m(PC) decreases as the content of electrolyte salt in the electrolyte solution increases.

[0274] Similarly, the frequency ν at which the intensity of the individually calculated DRS signal S1 (imaginary part of the dielectric constant) for the ion pair x (CIP) is maximized decreases as the content of electrolyte salt in the electrolyte solution increases. This suggests that the mobility of the ion pair x (CIP) decreases as the content of electrolyte salt in the electrolyte solution increases.

[0275] 5 and 6, the intensity of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the ion pair x (CIP) increases as the content of the electrolyte salt in the electrolyte solution increases. Thus, as the content of the electrolyte salt in the electrolyte solution increases, the concentration of the ion pair x (CIP) increases.

[0276] In this case, the cation (Li + ) and anion (PF6 - ) and the frequency of contact with each other (average coordination number), and it was confirmed that the average coordination number increases as the content of the electrolyte salt in the electrolyte solution increases.

[0277] Fourth, as is clear from FIG. 6, in the same system (electrolyte), the characteristic frequency ν x is the characteristic frequency ν of the neutral molecule m(PC) m This suggests that the response of the ion pair x (CIP) to the external electric field is slower than that of the neutral molecule m (PC), and therefore the mobility of the ion pair x (CIP) is lower than that of the neutral molecule m (PC).

[0278] Fifth, as is clear from FIG. 5, the static dielectric constant ε m sta and the static dielectric constant ε of the ion pair x (CIP) x sta Each of these decreased as the content of electrolyte salt in the electrolyte solution increased.

[0279] From these facts, it is clear that the electrolyte solution is a solvent (PC) and an electrolyte salt (LiPF 6 ), new and useful information was obtained regarding the physical properties of electrolytes in which component C contains a neutral molecule m (PC) and an ion pair x (CIP).

[0280] Specifically, based on the individual calculated DRS signal S1 and the calculated DRS signal S2, the physical property value P (relaxation strength Δε m , Δε x , characteristic time τ m , τ x , concentration n m , n x , static permittivity ε m sta , ε x sta and the salt dissociation degree α) could be obtained. In this case, the mobility of each component C could be grasped based on the physical property value P, and the dependency of the mobility of each component C on the concentration of the electrolyte could also be grasped.

[0281] Furthermore, not only the properties of the chemically static neutral molecule m but also the properties of the chemically dynamic ion pair x (CIP) could be grasped. In this case, the ionic dissociation property of the electrolyte salt in the electrolyte solution can be estimated based on the concentration of the ion pair x.

[0282] Furthermore, the ionic conductivity of the electrolyte can be estimated by utilizing the measurement error due to the ionic conductivity calculated in the measurement process of the actual DRS signal S3.

[0283] Experimental Example 2 As will be described below, the electrolyte solution was analyzed using the analysis device 100 (analysis method) described in the second embodiment to examine the physical properties of the electrolyte solution. The electrolyte solution used here contained propylene carbonate (PC) and diethyl carbonate (DEC) as a mixed solvent, and lithium hexafluorophosphate (LiPF ) as an electrolyte salt. 6 In this case, the mixing ratio (weight ratio) of the mixed solvent was PC:DEC=30:70.

[0284] [Configuration of the analysis device] The configuration of the analysis device 100 in Example 2 was the same as the configuration of the analysis device 100 in Example 1, except that the calculation unit 10 used calculation procedure 2 instead of calculation procedure 1 to calculate the individually calculated DRS signal S1.

[0285] [Analysis of Electrolyte Solution Using Analysis Device] According to the procedure described below, the electrolyte solution was analyzed using analysis device 100. Each of Figs. 9 to 11 shows the analysis results of the electrolyte solution using analysis device 100.

[0286] Specifically, Fig. 9 shows the calculation results of the individual calculated DRS signal S1 (imaginary part of permittivity) and the calculated DRS signal S2 (imaginary part of permittivity) (horizontal axis is frequency v (GHz), vertical axis is imaginary part of permittivity). Fig. 10 shows the calculation results of the calculated DRS signal S2 (real part and imaginary part of permittivity) (horizontal axis is frequency v (GHz), vertical axis is real part and imaginary part of permittivity).

[0287] FIG. 11 shows the measurement results of the measured DRS signal S3 (the real part and imaginary part of the dielectric constant) (the horizontal axis is the frequency ν (GHz), and the vertical axis is the real part and imaginary part of the dielectric constant).

[0288] (Calculation of individual calculated DRS signals S1 and calculation of calculated DRS signals S2) When analyzing an electrolyte solution using the analysis device 100, first, as described below, in the calculation unit 10, the calculated DRS signals S1 of each constituent component C were calculated using calculation procedure 2, and the calculated DRS signal S2 of the electrolyte solution was also calculated.

[0289] Specifically, first, the composition of the electrolyte was set in order to perform MD calculations for the electrolyte. In this case, as described above, PC and DEC were set as the solvent, and LiPF was set as the electrolyte salt. 6 As a result, the constituent C was selected to be propylene carbonate (C 4 H 6 O 3 ) and diethyl carbonate (C 5 H 10 O 3 ) and ion pair x CIP (Li + PF6 - ) was set.

[0290] Next, MD calculations were performed for the electrolyte solution. The calculation procedure for the MD calculation was the same as in Example 1. The electrolyte salt contents in the electrolyte solution were set to two types (0 M and 1 M). The electrolyte salt contents described here are the electrolyte salt contents relative to the solvent, as described above.

[0291] Next, based on the results of the MD calculation, the individual electric dipole moments of each component C (neutral molecule m and ion pair x (CIP)) were calculated, and then the rotational correlation function of each component C was calculated based on the individual electric dipole moments. In addition, the rotational correlation function was approximated to an exponential function to calculate the rotational correlation time of each component C. Furthermore, based on the rotational correlation time, the individual calculated DRS signal S1 (real part of the dielectric constant and imaginary part of the dielectric constant) of each component C was calculated, and then the calculated DRS signal S2 (real part of the dielectric constant and imaginary part of the dielectric constant) of the electrolyte was calculated.

[0292] Details of the calculation procedure for the individual electric dipole moment, the calculation procedure for the rotational correlation function, the approximation procedure for the rotational correlation function, the calculation procedure for the rotational correlation time, the calculation procedure for the individual calculated DRS signal S1, and the calculation procedure for the calculated DRS signal S2 are as described above.

[0293] As a result, an individual calculated DRS signal S1 (imaginary part of dielectric constant) for each component C (neutral molecules m (PC, DEC) and ion pair (CIP)) was obtained, as shown in Fig. 9. In Fig. 9, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the imaginary part of dielectric constant.

[0294] Furthermore, a calculated DRS signal S2 of the electrolyte solution was obtained as shown in Fig. 10. In Fig. 10, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the real part and imaginary part of the dielectric constant.

[0295] 9 shows not only the individual calculated DRS signal S1 (imaginary part of permittivity) but also the calculated DRS signal S2 (imaginary part of permittivity). In addition, in FIG. 10, the positional relationship between the real part of permittivity and the imaginary part of permittivity is adjusted.

[0296] 9, the relationship between 9A to 9G and the content of electrolyte salt in the electrolyte solution is 9A to 9C = 0 M, and 9D to 9G = 1 M. Also shown in Fig. 9 are 9A and 9D = the individual calculated DRS signal S1 of neutral molecule m (DEC), 9B and 9E = the individual calculated DRS signal S1 of neutral molecule m (PC), 9F = the individual calculated DRS signal S1 of ion pair x (CIP), and 9C and 9G = the calculated DRS signal S2.

[0297] 10, the relationship between 10A to 10D and the content of electrolyte salt in the electrolytic solution is 10A, 10C = 0 M, and 10B, 10D = 1 M. Also, in Fig. 10, 10A and 10B indicate the calculated DRS signal S2 (real part of dielectric constant), and 10C and 10D indicate the calculated DRS signal S2 (imaginary part of dielectric constant).

[0298] (Calculation of Physical Property Value P) Next, in the calculation unit 10, a physical property value P specific to each constituent component C was calculated based on the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0299] Here, the physical property value P of the neutral molecule m (PC, DEC) is the relaxation strength Δε m , characteristic time τ m , concentration n m and static permittivity ε m sta The relaxation strength Δε was calculated as the physical property P of the ion pair x (CIP). x , characteristic time τ x , concentration n x and static permittivity ε x sta In addition, the salt dissociation degree α of the electrolyte was calculated.

[0300] As a result, when the content of the electrolyte salt in the electrolytic solution was 1M, the physical property value P was as follows: m = 9.2, characteristic time τ m =31.5ps, concentration n m =2.9M, static permittivity ε m sta = 9,2. For the neutral molecule m(DEC), the relaxation intensity Δε m = 0.6, characteristic time τ m =13.5ps, concentration n m =5.9M, static permittivity ε m sta = 0.6. For the ion pair x (CIP), the relaxation strength Δε x = 4.1, characteristic time τ x =180.0ps, concentration n x =0.4M, static permittivity ε x staThe salt dissociation degree α of the electrolyte was 0.51.

[0301] (Measurement of Measured DRS Signal S3) Next, the measured DRS signal S3 was measured in the measurement unit 20 as described below.

[0302] Specifically, first, an electrolyte solution was prepared. In this case, as described above, an electrolyte salt (LiPF ) was added to a mixed solvent (PC and DEC). 6 ) was added, and the mixed solvent was stirred to prepare an electrolyte solution.

[0303] The content (M) of the electrolyte salt in the electrolytic solution was set to two levels (0 M and 1 M). The content of the electrolyte salt described here is the content of the electrolyte salt relative to the solvent.

[0304] Subsequently, the electrolyte solution was analyzed using dielectric relaxation spectroscopy to measure the measured DRS signal S3 of the electrolyte solution. The details of the measurement procedure for the measured DRS signal S3 were the same as in Example 1.

[0305] As a result, the measured DRS signal S3 shown in Fig. 11 was obtained. In Fig. 11, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the real part and imaginary part of the dielectric constant. Note that Fig. 11 shows the real part and imaginary part of the dielectric constant together. As described above, two types of electrolyte salt contents were set in the electrolytic solution, and therefore, Fig. 11 shows two types of real part of the dielectric constant and two types of imaginary part of the dielectric constant.

[0306] 11, the relationship between 11A to 11D and the content of electrolyte salt in the electrolytic solution is 11A, 11C = 0 M, and 11B, 11D = 1 M. Also, in Fig. 11, 11A and 11B indicate the measured DRS signal S3 (real part of dielectric constant), and 11C and 11D indicate the measured DRS signal S3 (imaginary part of dielectric constant).

[0307] (Comparison of calculated DRS signal S2 with measured DRS signal S3 and attribution of measured DRS signal S3 using individual calculated DRS signal S1) Finally, as described below, the calculated DRS signal S2 and the measured DRS signal S3 were compared with each other in the comparison unit 30.

[0308] Specifically, we checked whether the spectral shapes of the calculated DRS signal S2 shown in Fig. 10 and the measured DRS signal S3 shown in Fig. 11 qualitatively matched each other, and as a result, we found the following tendency.

[0309] Specifically, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the frequency ν at which the intensity of the imaginary part of the dielectric constant was maximized decreased, and more specifically, the frequency ν decreased from approximately 7 GHz to approximately 2 GHz.

[0310] Furthermore, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the maximum value of the intensity of the imaginary part of the dielectric constant decreased, and more specifically, the maximum value of the intensity of the imaginary part of the dielectric constant decreased from approximately 6 to approximately 3.

[0311] Furthermore, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the intensity of the real part of the dielectric constant at the minimum frequency ν (approximately 0.2 GHz) decreased; more specifically, the intensity of the real part of the dielectric constant decreased from approximately 16 to approximately 12.

[0312] In contrast, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the frequency ν at which the intensity of the imaginary part of the dielectric constant was maximized decreased, and more specifically, the frequency ν decreased from approximately 10 GHz to approximately 2 GHz.

[0313] Furthermore, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the maximum value of the intensity of the imaginary part of the dielectric constant decreased, and more specifically, the maximum value of the intensity of the imaginary part of the dielectric constant decreased from approximately 8 to approximately 5.

[0314] Furthermore, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the intensity of the real part of the dielectric constant at the time when the frequency ν was at its minimum (=approximately 0.2 GHz) decreased; more specifically, the intensity of the real part of the dielectric constant decreased from approximately 16 to approximately 13.

[0315] These trends indicate that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively matched each other. This ensured the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3, and therefore ensured the reliability of the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2. Therefore, the measured DRS signal S3 could be attributed using the individual calculated DRS signal S1.

[0316] [Discussion] Since the reliability of the calculated DRS signal S2 for the electrolyte was ensured, the reliability of the individual calculated DRS signals S1 for each component C (neutral molecules m (PC and DEC) and ion pairs x (CIP)) was also ensured. As a result, the physical properties described below were derived from the results shown in Figures 9 to 11.

[0317] 9 to 11, the spectral shape of the measured DRS signal S3 is determined mainly by the spectral shape of the neutral molecule m (PC) when the content of the electrolyte salt in the electrolyte solution is in the range of 0 M to 2 M. As a result, the spectral shape of the neutral molecule m (DEC) has almost no effect on the spectral shape of the measured DRS signal S3.

[0318] However, the frequency v at which the intensity of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the neutral molecule m (DEC) is maximized is greater than the frequency v at which the intensity of the individual calculated DRS signal S1 (imaginary part of the dielectric constant) for the neutral molecule m (PC) is maximized. This suggests that the mobility of the neutral molecule m (DEC) is higher than that of the neutral molecule m (PC).

[0319] The spectral shape of the calculated DRS signal S3 when the electrolyte salt content in the electrolyte solution is large (=1 M) is broader than the spectral shape of the calculated DRS signal S3 when the electrolyte salt content in the electrolyte solution is small (=0 M). In this case, the frequency ν at which the intensity of the imaginary part of the dielectric constant is maximized in the former case is lower than the frequency ν at which the intensity of the imaginary part of the dielectric constant is maximized in the latter case.

[0320] As a result, as described above, the spectral shape of the measured DRS signal S3 is mainly determined by the neutral molecule m (PC). However, in the region where the frequency v is small, the neutral molecule m (DEC) also has a significant influence on the spectral shape of the measured DRS signal S3.

[0321] Second, as is clear from Figures 7 and 11, the relaxation strength Δε in Example 2 is greater than that in Example 1. As described above, this relaxation strength Δε represents the influence of the ion pair x (CIP) on the physical properties of the electrolyte solution. This suggests that even if the content of the electrolyte salt in the electrolyte solution is constant, increasing the proportion (mixing ratio) of DEC in the mixed solvent makes it easier for the ion pair x (CIP) to be formed in the electrolyte solution.

[0322] From these findings, it was found that the mixed solvent (PC and DEC) and the electrolyte salt (LiPF 6 ), new and useful information was obtained regarding the physical properties of electrolytes containing neutral molecules m (PC and DEC) and ion pairs x (CIP) as component C.

[0323] In detail, the same advantages as those in Example 1 were obtained. In this case, in particular, the same advantages were obtained even when a mixed solvent was used.

[0324] Experimental Example 3 As will be described below, the electrolyte solution was analyzed using the analysis device 100 (analysis method) described in the first embodiment to examine the physical properties of the electrolyte solution. The electrolyte solution used here contained diethyl carbonate (DEC) as a solvent and lithium hexafluorophosphate (LiPF ) as an electrolyte salt. 6 )

[0325] [Configuration of Analysis Apparatus] The configuration of the analysis apparatus 100 in the third embodiment is the same as the configuration of the analysis apparatus 100 in the first embodiment.

[0326] [Analysis of Electrolyte Solution] According to the procedure described below, the electrolyte solution was analyzed using the analysis device 100. Each of Figs.

[0327] Specifically, each of Figures 12 and 13 shows the calculation results (horizontal axis is frequency ν (GHz), vertical axis is the imaginary part of the dielectric constant) of the individual calculated DRS signal S1 for an electrolyte solution with an electrolyte salt content of 1 M. However, Figure 12 shows the calculation results when the constituent component C is a three-component system, and Figure 13 shows the calculation results when the constituent component C is a two-component system. The details of the "three-component system" and "two-component system" described here will be described later.

[0328] 14 shows the calculation results of the calculated DRS signal S2 (the real part and imaginary part of the dielectric constant) (the horizontal axis is the frequency ν (GHz), and the vertical axis is the real part and imaginary part of the dielectric constant). FIG. 14 shows the calculation results for an electrolyte solution with an electrolyte salt content of 1 M and a three-component system of component C. FIG. 15 shows the measurement results of the measured DRS signal S3 (the real part and imaginary part of the dielectric constant) (the horizontal axis is the frequency ν (GHz), and the vertical axis is the real part and imaginary part of the dielectric constant).

[0329] (Calculation of individual calculated DRS signals S1 and calculation of calculated DRS signals S2) When analyzing an electrolyte solution using the analysis device 100, first, as described below, the calculation unit 10 calculated the individual calculated DRS signals S1 of each constituent component C using calculation procedure 1, and also calculated the calculated DRS signal S2 of the electrolyte solution.

[0330] Specifically, first, the composition of the electrolyte was set in order to perform MD calculations for the electrolyte. In this case, as described above, DEC was set as the solvent and LiPF 6 was set as the electrolyte salt. 6 was set.

[0331] In this case, a system containing three types of constituent components C (ternary system) is composed of a neutral molecule m, DEC(C 5 H 10 O 3 ) and ion pair x CIP (Li + PF6 - ) and an ion pair x, an ion associate (Li 2 (PF 6 ) 2 In this case, Li was used as the ion pair x.2 (PF 6 ) 2 Not only Li 2 PF 6 and Li(PF 6 ) 2 We set up several types of ion associates, including

[0332] For comparison, a system containing two types of constituent components C (two-component system) was prepared using a neutral molecule m, DEC (C 5 H 10 O 3 ) and ion pair x CIP (Li + PF6 - ) was set.

[0333] Next, MD calculations were performed on the electrolyte solutions. The calculation procedures for the MD calculations were the same as in Example 1. The electrolyte solutions were provided with two different electrolyte salt contents (0 M and 1 M).

[0334] Subsequently, based on the calculation results of the MD calculation, the individual calculated DRS signals S1 (real part and imaginary part of the dielectric constant) of each constituent component C (neutral molecule m (DEC) and ion pair x (CIP and ion associate)) in the ternary system were calculated in the same manner as in Example 1, and then the calculated DRS signal S2 (real part and imaginary part of the dielectric constant) of the electrolyte solution was calculated.

[0335] For comparison, based on the calculation results of the MD calculation, the individual calculated DRS signals S1 (real part and imaginary part of the dielectric constant) of each constituent component C (neutral molecule m (DEC) and ion pair x (CIP)) in the two-component system were calculated in the same manner as in Example 1, and then the calculated DRS signal S2 (real part and imaginary part of the dielectric constant) of the electrolyte was calculated.

[0336] As a result, an individually calculated DRS signal S1 (imaginary part of dielectric constant) for the three-component system (component C is neutral molecule m (DEC) and ion pair x (CIP and ion associate)) was obtained, as shown in Fig. 12. In Fig. 12, as described above, the horizontal axis represents frequency v (GHz) and the vertical axis represents the imaginary part of dielectric constant.

[0337] Furthermore, as shown in Fig. 13, an individually calculated DRS signal S1 (imaginary part of dielectric constant) was obtained for a two-component system (component C is a neutral molecule m (DEC) and an ion pair x (CIP)). In Fig. 13, as described above, the horizontal axis represents frequency v (GHz) and the vertical axis represents the imaginary part of dielectric constant.

[0338] Furthermore, a calculated DRS signal S2 of the electrolyte was obtained as shown in Fig. 14. In Fig. 14, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the real part and imaginary part of the dielectric constant.

[0339] 12 and 13, as described above, not only the individual calculated DRS signal S1 but also the calculated DRS signal S2 are shown. In addition, in FIG. 14, the positional relationship between the real part of the dielectric constant and the imaginary part of the dielectric constant is adjusted.

[0340] 12, the relationship between 12A to 12D and the content of electrolyte salt in the electrolyte solution is 12A to 12D = 1 M. Also, FIG. 12 shows 12A = the individually calculated DRS signal S1 (imaginary part of the dielectric constant) of neutral molecule m (DEC), 12B = the individually calculated DRS signal S1 (imaginary part of the dielectric constant) of ion pair x (CIP), 12C = the individually calculated DRS signal S1 (imaginary part of the dielectric constant) of ion pair x (ion associate), and 12D = the calculated DRS signal S2 (imaginary part of the dielectric constant) of the electrolyte solution.

[0341] 13, the relationship between 13A to 13C and the content of electrolyte salt in the electrolyte solution is 13A to 13C = 1 M. Also, FIG. 13 shows 13A = the individual calculated DRS signal S1 (imaginary part of dielectric constant) of neutral molecule m (DEC), 13B = the individual calculated DRS signal S1 (imaginary part of dielectric constant) of ion pair x (CIP), and 13C = the calculated DRS signal S2 (imaginary part of dielectric constant) of the electrolyte solution.

[0342] 14, the relationship between 14A to 14D and the content of electrolyte salt in the electrolytic solution is 14A, 14C = 0 M, and 14B, 14D = 1 M. Also, in Fig. 14, 14A, 14B = calculated DRS signal S2 (real part of dielectric constant), and 14C, 14D = calculated DRS signal S2 (imaginary part of dielectric constant).

[0343] (Calculation of Physical Property Value P) Next, in the calculation unit 10, a physical property value P specific to each constituent component C was calculated based on the individual calculated DRS signal S1 and the calculated DRS signal S2.

[0344] Here, the physical property value P of the neutral molecule m (DEC) is the relaxation strength Δε m , characteristic time τ m , concentration n m and static permittivity ε m sta The relaxation strength Δε was calculated as the physical property P of the ion pair x (CIP and ion associate). x , characteristic time τ x , concentration n x and static permittivity ε x sta In addition, the salt dissociation degree α of the electrolyte was calculated.

[0345] As a result, when the content of the electrolyte salt in the electrolytic solution was 1M, the physical property value P was as follows: m = 0.9, characteristic time τ m =9.3 ps, concentration n m = 7.8 M, static dielectric constant ε m sta = 0.9. For the ion pair x (CIP), the relaxation strength Δε x = 6.5, characteristic time τ x =453.0ps, concentration n x =0.5M, static permittivity ε x sta = 6.5. The relaxation strength Δε x = 2.7, characteristic time τ x =76.0 ps, ​​concentration n x =0.1M, static permittivity ε x sta The salt dissociation degree α of the electrolyte was 0.28.

[0346] (Measurement of Measured DRS Signal S3) Next, the measured DRS signal S3 was measured in the measurement unit 20 as described below.

[0347] Specifically, first, an electrolyte solution was prepared. In this case, as described above, an electrolyte salt (LiPF ) was dissolved in a solvent (DEC). 6 ) was added to the solvent, and the solvent was stirred to prepare an electrolyte solution.

[0348] The content (M) of the electrolyte salt in the electrolytic solution was set to two levels (0 M and 1 M). The content of the electrolyte salt described here is the content of the electrolyte salt relative to the solvent.

[0349] Subsequently, the electrolyte solution was analyzed using dielectric relaxation spectroscopy to measure the measured DRS signal S3 of the electrolyte solution. The measurement procedure for the measured DRS signal S3 was the same as in Example 1.

[0350] As a result, the measured DRS signal S3 (real part of the dielectric constant and imaginary part of the dielectric constant) shown in Fig. 15 was obtained. In Fig. 15, as described above, the horizontal axis represents frequency v (GHz), and the vertical axis represents the real part of the dielectric constant and the imaginary part of the dielectric constant. Note that Fig. 15 shows the real part of the dielectric constant and the imaginary part of the dielectric constant together. As described above, the content of the electrolyte salt in the electrolytic solution was set to two types, and therefore, Fig. 15 shows two types of real part of the dielectric constant and two types of imaginary part of the dielectric constant.

[0351] 15, the relationship between 15A to 15D and the content of electrolyte salt in the electrolytic solution is 15A, 15C = 0 M, and 15B, 15D = 1 M. Also, in Fig. 15, 15A, 15B = measured DRS signal S3 (real part of dielectric constant), and 15C, 15D = measured DRS signal S3 (imaginary part of dielectric constant).

[0352] (Comparison of calculated DRS signal S2 with measured DRS signal S3 and attribution of measured DRS signal S3 using individual calculated DRS signal S1) Finally, as described below, the calculated DRS signal S2 and the measured DRS signal S3 were compared with each other in the comparison unit 30.

[0353] Specifically, we checked whether the spectral shapes of the calculated DRS signal S2 shown in Fig. 14 and the measured DRS signal S3 shown in Fig. 15 qualitatively matched each other, and found the following tendency.

[0354] Specifically, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the frequency ν at which the intensity of the imaginary part of the dielectric constant was at its maximum decreased, and more specifically, the frequency ν decreased from approximately 20 GHz to approximately 0.5 GHz.

[0355] Furthermore, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the maximum value of the intensity of the imaginary part of the dielectric constant increased, and more specifically, the maximum value of the imaginary part of the dielectric constant increased from approximately 0.5 to approximately 3.

[0356] Furthermore, in the measured DRS signal S3, as the content of electrolyte salt in the electrolyte solution increased, the intensity of the real part of the dielectric constant at the minimum frequency ν (approximately 0.2 GHz) increased, and more specifically, the intensity of the real part of the dielectric constant increased from approximately 3 to approximately 10.

[0357] In contrast, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the frequency ν at which the intensity of the imaginary part of the dielectric constant was at its maximum decreased, and more specifically, the frequency ν decreased from approximately 30 GHz to approximately 0.5 GHz.

[0358] Furthermore, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the maximum value of the intensity of the imaginary part of the dielectric constant increased, and more specifically, the maximum value of the intensity of the imaginary part of the dielectric constant increased from approximately 0.5 to approximately 4.

[0359] Furthermore, in the calculated DRS signal S2, as the content of electrolyte salt in the electrolyte solution increased, the intensity of the real part of the dielectric constant at the time when the frequency ν was at its minimum (=approximately 0.2 GHz) increased, and more specifically, the intensity of the real part of the dielectric constant increased from approximately 1 to approximately 10.

[0360] These trends indicate that the calculated DRS signal S2 and the measured DRS signal S3 qualitatively matched each other. This ensured the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3, and therefore ensured the reliability of the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2. Therefore, the measured DRS signal S3 could be attributed using the individual calculated DRS signal S1.

[0361] [Discussion] Because the reliability of the calculated DRS signal S2 for the electrolyte was ensured, the reliability of the individual calculated DRS signals S1 for each component C (neutral molecule m (DEC) and ion pair x (CIP and ion associate)) was also ensured. As a result, the results shown in FIGS. 12 to 15 revealed similar trends to those derived in Example 1 regarding the spectral shape of the measured DRS signal S3, the mobility of neutral molecule m, the effect of ion pair x on the spectral shape, the ease of forming ion pair x (CIP), and the like.

[0362] In particular, the individually calculated DRS signal S1 for the three-component system shown in FIG. 12 (component C is neutral molecule m (DEC) and ion pair x (CIP and ion associate)) and the individually calculated DRS signal S1 for the two-component system shown in FIG. 13 (component C is neutral molecule m (DEC) and ion pair x (CIP)) showed the following tendency.

[0363] As is clear from FIG. 13 , in the calculated DRS signal S2 of the two-component system in which the ion associate as the ion pair x was not taken into consideration, the intensity of the imaginary part of the dielectric constant locally decreased in the frequency band where ν was approximately 5 GHz, resulting in a so-called depression.

[0364] In contrast, as is clear from Fig. 12, the above-mentioned dip did not occur in the calculated DRS signal S2 of the three-component system, which took into account the ion associate as the ion pair x. As a result, the behavior of the imaginary part of the dielectric constant in the frequency band of approximately 1 GHz to 10 GHz shown in Fig. 12 showed a tendency similar to the behavior of the imaginary part of the dielectric constant in the same band of the measured DRS signal S3 shown in Fig. 15, and more specifically, the imaginary part of the dielectric constant changed almost linearly.

[0365] This resulted in the formation of a solvent (DEC) and an electrolyte salt (LiPF 6 In the electrolyte solution containing the electrolyte salt (content of the electrolyte salt in the electrolyte solution = 1M), one type of cation (Li + ) and one kind of anion (PF6-) approach each other, CIP (LiPF 6 ) is not formed inside this electrolyte. + ) and two kinds of anions (PF6-) associate with each other to form a special ion associate (Li 2 (PF 6 ) 2 ) is thought to be formed.

[0366] From these findings, it was found that the solvent (DEC) and the electrolyte salt (LiPF 6 ), new and useful information was obtained regarding the physical properties of an electrolyte solution containing a neutral molecule m (DEC) and an ion pair x (CIP and an ion associate) as component C. In this case, it was confirmed that not only was CIP influencing the physical properties of the electrolyte solution, but also that the ion associate was influencing the physical properties of the electrolyte solution, and therefore the influence of the ion associate could also be understood.

[0367] Specifically, it was possible to obtain the same advantages as in Example 1. In this case, in particular, it was possible to obtain the same advantages even when focusing on an ion associate rather than just CIP as the ion pair x.

[0368] 3 to 15, analyzing the electrolyte solution using the analysis device 100 (analysis method) ensured the reliability of the calculated DRS signal S2 relative to the measured DRS signal S3, and also ensured the reliability of the individual calculated DRS signal S1, which is a component of the calculated DRS signal S2. Therefore, the measured DRS signal S3 could be assigned using the individual calculated DRS signal S1. This enabled the acquisition of a physical property value P specific to each constituent component C, and the understanding of not only the physical properties of the neutral molecule m but also the physical properties of the ion pair x (CIP and ion associate). Therefore, the physical properties of the electrolyte solution can be analyzed easily and with high accuracy.

[0369] The present technology has been described above using several embodiments and examples, but the configuration of the present technology is not limited to the configurations described in the respective embodiments and examples, and can be modified in various ways.

[0370] The effects described in this specification are merely examples, and the effects of the present technology are not limited to the effects described in this specification. Therefore, other effects may be obtained with respect to the present technology.

[0371] The present technology may also be configured as follows. <1> An analysis method comprising: calculating the behavior over time of a series of atoms constituting a component of an electrolyte solution by performing a molecular dynamics calculation on the electrolyte solution; calculating a first dielectric relaxation spectrum signal of the component based on the behavior over time of the series of atoms; calculating a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal; and calculating a physical property value specific to the component based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal. <2> The analysis method according to <1>, in which the electrolyte solution includes a solvent and an electrolyte salt, and the component includes at least one of a neutral molecule and an ion pair. <3> The analysis method according to <1> or <2>, in which the physical property value includes at least one of a characteristic time, a relaxation strength, a static dielectric constant, a concentration, and a degree of salt dissociation. <4> The analysis method according to any one of <1> to <3>, wherein: calculating the first dielectric relaxation spectrum signal comprises calculating a total electric dipole moment of the constituent component based on the behavior of the series of atoms over time, calculating a time correlation function of the constituent component based on the total electric dipole moment, approximating the time correlation function to an exponential function, and calculating the first dielectric relaxation spectrum signal of the constituent component by Fourier transforming the approximation result of the time correlation function. <5> The analysis method according to any one of <1> to <3>, wherein: calculating the first dielectric relaxation spectrum signal comprises calculating individual electric dipole moments of the constituent component based on the behavior of the series of atoms over time, calculating a rotational correlation function of the constituent component based on the individual electric dipole moments, calculating a rotational correlation time of the constituent component by approximating the rotational correlation function to an exponential function, and calculating the first dielectric relaxation spectrum signal of the constituent component based on the rotational correlation time.<6> The analysis method according to any one of <1> to <5>, wherein the constituent components include two or more types of neutral molecules and ion pairs, and the first dielectric relaxation spectrum signal is calculated for each of the two or more types of constituent components, and the second dielectric relaxation spectrum signal is calculated by adding the first dielectric relaxation spectrum signals for the two or more types of constituent components. <7> The analysis method according to any one of <1> to <6>, further comprising: analyzing the electrolytic solution using dielectric relaxation spectroscopy to measure a third dielectric relaxation spectrum signal of the electrolytic solution, and comparing the second dielectric relaxation spectrum signal and the third dielectric relaxation spectrum signal to assign the third dielectric relaxation spectrum signal using the first dielectric relaxation spectrum signal. <8> The analysis method according to <7>, further comprising: after measuring the third dielectric relaxation spectrum signal, correcting the third dielectric relaxation spectrum signal by removing a signal component due to ionic conductivity of the electrolytic solution from the third dielectric relaxation spectrum signal, and comparing the corrected second dielectric relaxation spectrum signal and the corrected third dielectric relaxation spectrum signal with each other. <9> An analytical device comprising a calculation unit that calculates physical property values ​​related to an electrolyte solution, wherein the calculation unit calculates the behavior over time of a series of atoms constituting a component of the electrolyte solution by performing a molecular dynamics calculation on the electrolyte solution, calculates a first dielectric relaxation spectrum signal of the component based on the behavior over time of the series of atoms, calculates a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal, and calculates the physical property values ​​specific to the component based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal. <10> The analytical device according to <9>, wherein the electrolyte solution includes a solvent and an electrolyte salt, and the component includes at least one of neutral molecules and ion pairs. <11> The analytical device according to <9> or <10>, wherein the physical property values ​​include at least one of characteristic time, relaxation strength, static dielectric constant, concentration, and salt dissociation degree.<12> The analysis device according to any one of <9> to <11>, wherein, in order to calculate the first dielectric relaxation spectrum signal, the calculation unit calculates a total electric dipole moment of the constituent component based on the behavior of the series of atoms over time, calculates a time correlation function of the constituent component based on the total electric dipole moment, approximates the time correlation function to an exponential function, and calculates the first dielectric relaxation spectrum signal of the constituent component by Fourier transforming the approximation result of the time correlation function. <13> The analysis device according to any one of <9> to <11>, wherein, in order to calculate the first dielectric relaxation spectrum signal, the calculation unit calculates individual electric dipole moments of the constituent component based on the behavior of the series of atoms over time, calculates a rotational correlation function of the constituent component based on the individual electric dipole moments, calculates a rotational correlation time of the constituent component by approximating the rotational correlation function to an exponential function, and calculates the first dielectric relaxation spectrum signal of the constituent component based on the rotational correlation time. <14> The analytical device according to any one of <9> to <13>, wherein the constituent components include two or more types of neutral molecules and ion pairs, and the calculation unit calculates the first dielectric relaxation spectrum signal for each of the two or more types of constituent components, and calculates the second dielectric relaxation spectrum signal by adding the first dielectric relaxation spectrum signals for the two or more types of constituent components. <15> The analytical device according to any one of <9> to <14>, further comprising: a measurement unit that measures a third dielectric relaxation spectrum signal of the electrolytic solution by analyzing the electrolytic solution using a dielectric relaxation spectroscopy method, and a comparison unit that assigns the third dielectric relaxation spectrum signal using the first dielectric relaxation spectrum signal by comparing the second dielectric relaxation spectrum signal with the third dielectric relaxation spectrum signal.<16> The analysis device according to <15>, wherein the measurement unit, after measuring the third dielectric relaxation spectrum signal, corrects the third dielectric relaxation spectrum signal by removing a signal component caused by ionic conductivity of the electrolyte solution from the third dielectric relaxation spectrum signal, and the comparison unit compares the second dielectric relaxation spectrum signal with a correction result of the third dielectric relaxation spectrum signal.

Claims

1. A molecular dynamics calculation is performed on the electrolyte to calculate the behavior of a series of atoms constituting the components of the electrolyte over time; calculating a first dielectric relaxation spectrum signal of the constituent based on the behavior of the set of atoms over time; calculating a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal; calculating a physical property value specific to the constituent based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal; Analysis method.

2. The electrolyte solution includes a solvent and an electrolyte salt, The components include at least one of neutral molecules and ion pairs; The analysis method according to claim 1 .

3. The physical property value includes at least one of a characteristic time, a relaxation strength, a static dielectric constant, a concentration, and a salt dissociation degree. The analysis method according to claim 1 .

4. To calculate the first dielectric relaxation spectrum signal, calculating a total electric dipole moment for the constituent based on the behavior of the set of atoms over time; calculating a time correlation function of the constituent components based on the total electric dipole moment; Approximating the time correlation function to an exponential function; Calculating the first dielectric relaxation spectrum signal of the component by Fourier transforming the approximation result of the time correlation function; The analysis method according to any one of claims 1 to 3.

5. To calculate the first dielectric relaxation spectrum signal, calculating individual electric dipole moments of said constituents based on the behavior of said set of atoms over time; calculating rotational correlation functions of the components based on the individual electric dipole moments; calculating the rotational correlation times of the components by approximating the rotational correlation function to an exponential function; calculating the first dielectric relaxation spectrum signal of the constituent based on the rotational correlation time; The analysis method according to any one of claims 1 to 3.

6. The constituents include two or more of neutral molecules and ion pairs; calculating said first dielectric relaxation spectrum signal for each of two or more of said components; calculating the second dielectric relaxation spectrum signal by summing the first dielectric relaxation spectrum signals for two or more of the constituents; The analysis method according to any one of claims 1 to 3.

7. moreover, analyzing the electrolyte solution using dielectric relaxation spectroscopy to measure a third dielectric relaxation spectrum signal of the electrolyte solution; attributing the third dielectric relaxation spectrum signal using the first dielectric relaxation spectrum signal by comparing the second dielectric relaxation spectrum signal and the third dielectric relaxation spectrum signal to each other. The analysis method according to any one of claims 1 to 3.

8. After measuring the third dielectric relaxation spectrum signal, a signal component caused by the ionic conductivity of the electrolyte is removed from the third dielectric relaxation spectrum signal to correct the third dielectric relaxation spectrum signal; comparing the second dielectric relaxation spectrum signal and the corrected result of the third dielectric relaxation spectrum signal with each other; The analysis method according to claim 7.

9. A calculation unit is provided for calculating physical property values ​​related to the electrolyte, The calculation unit is A molecular dynamics calculation is performed on the electrolyte to calculate the behavior of a series of atoms constituting the electrolyte over time; calculating a first dielectric relaxation spectrum signal of the constituent based on the behavior of the set of atoms over time; calculating a second dielectric relaxation spectrum signal of the electrolyte solution based on the first dielectric relaxation spectrum signal; Calculating the physical property value specific to the constituent based on the first dielectric relaxation spectrum signal and the second dielectric relaxation spectrum signal. Analysis device.

10. The electrolyte solution includes a solvent and an electrolyte salt, The components include at least one of neutral molecules and ion pairs; The analysis device according to claim 9.

11. The physical property value includes at least one of a characteristic time, a relaxation strength, a static dielectric constant, a concentration, and a salt dissociation degree. The analysis device according to claim 9.

12. The calculation unit calculates the first dielectric relaxation spectrum signal. calculating a total electric dipole moment for the constituent based on the behavior of the set of atoms over time; calculating a time correlation function of the constituent components based on the total electric dipole moment; Approximating the time correlation function to an exponential function; Calculating the first dielectric relaxation spectrum signal of the component by Fourier transforming the approximation result of the time correlation function; The analysis device according to any one of claims 9 to 11.

13. The calculation unit calculates the first dielectric relaxation spectrum signal. calculating individual electric dipole moments of said constituents based on the behavior of said set of atoms over time; calculating rotational correlation functions of the components based on the individual electric dipole moments; calculating the rotational correlation times of the components by approximating the rotational correlation function to an exponential function; calculating the first dielectric relaxation spectrum signal of the constituent based on the rotational correlation time; The analysis device according to any one of claims 9 to 11.

14. The constituents include two or more of neutral molecules and ion pairs; The calculation unit is calculating said first dielectric relaxation spectrum signal for each of two or more of said components; calculating the second dielectric relaxation spectrum signal by summing the first dielectric relaxation spectrum signals for two or more of the constituents; The analysis device according to any one of claims 9 to 11.

15. moreover, a measuring unit for measuring a third dielectric relaxation spectrum signal of the electrolyte by analyzing the electrolyte using a dielectric relaxation spectroscopy method; a comparison unit for comparing the second dielectric relaxation spectrum signal with the third dielectric relaxation spectrum signal to assign the third dielectric relaxation spectrum signal using the first dielectric relaxation spectrum signal; The analysis device according to any one of claims 9 to 11, comprising:

16. the measurement unit corrects the third dielectric relaxation spectrum signal by removing a signal component caused by ionic conductivity of the electrolyte from the third dielectric relaxation spectrum signal after measuring the third dielectric relaxation spectrum signal; The comparison unit compares the second dielectric relaxation spectrum signal and the correction result of the third dielectric relaxation spectrum signal with each other. The analysis device according to claim 15.