JP7438543B2 - Evaluation method for electrochemical devices - Google Patents

Description

The present invention relates to a structure, an electrochemical device, and a method for supporting evaluation of a structure.

Lithium ion capacitors, electric double layer capacitors, and fuel cells are known as electrochemical devices.

A lithium ion capacitor usually includes an electrode containing activated carbon as a positive electrode, and a lithium storage carbon material similar to the negative electrode of a lithium ion battery as a negative electrode. A lithium ion capacitor performs charging and discharging by adsorbing and desorbing ions at a positive electrode and intercalating and desorbing lithium ions at a negative electrode (see, for example, Patent Document 1).

An electric double layer capacitor usually includes electrodes containing activated carbon as a positive electrode and a negative electrode. In an electric double layer capacitor, charging and discharging are performed by physical adsorption and desorption of electrolyte ions (see, for example, Patent Document 1).

In a lithium ion capacitor and an electric double layer capacitor, the larger the contact area between the electrode and the electrolyte, the higher the capacitance. Activated carbon is porous, and many pores are formed on the surface of activated carbon. Therefore, activated carbon has a large specific surface area, and by using activated carbon as an electrode material, capacitance can be increased. In other words, by using a porous material for the electrode, the performance of the lithium ion capacitor and the electric double layer capacitor can be improved.

Fuel cells are classified into various types depending on the type of electrolyte, the type of electrode, etc. Typical examples include alkaline type (AFC), phosphoric acid type (PAFC), molten carbonate type (MCFC), solid oxide type (SOFC), and solid polymer type (PEFC).

For example, a polymer electrolyte fuel cell includes a membrane-electrode assembly (MEA). The membrane-electrode assembly is composed of a polymer electrolyte membrane, a cathode electrode, and an anode electrode. The cathode side electrode and the anode side electrode are formed on both sides of the polymer electrolyte membrane. The cathode side electrode and the anode side electrode include an electrode catalyst layer and a gas diffusion layer, and the electrode catalyst layer usually contains carbon black. Carbon black supports a catalyst such as platinum. Further, carbon black supports an ionomer (ion exchange polymer) (see, for example, Patent Documents 2 and 3).

In a polymer electrolyte fuel cell, the larger the contact area between the ionomer and the catalyst in the catalyst layer, the higher the current density. Carbon black (secondary particles) is porous, and many pores are formed on the surface of carbon black. Therefore, carbon black has a large specific surface area, and by using carbon black as a catalyst support, it is possible to increase the amount of the ionomer and catalyst supported and thereby increase the current density. In other words, the performance of the polymer electrolyte fuel cell can be improved by using a porous material for the catalyst support and supporting the ionomer and catalyst in the pores.

Japanese Patent Application Publication No. 2017-168832 Japanese Patent Application Publication No. 2016-085894 Japanese Patent Application Publication No. 2006-004662

However, even when porous materials are used for the electrodes of electrochemical devices, if the amount of electrolytic solution or electrolytic material such as ionomer that enters the pores is small, the characteristics of the electrochemical device can be improved. I can't do it.

The present inventor conducted extensive studies on electrochemical devices and completed the present invention. An object of the present invention is to provide a structure that improves the performance of an electrochemical device, an electrochemical device equipped with the structure, and a method for supporting evaluation of the structure.

A structure according to the present invention includes an electrolytic material and a carrier supporting the electrolytic material. The carrier includes a plurality of particles, and each of the plurality of particles has pores. Further, the graph showing the ratio of the number of particles to the volume magnetic susceptibility includes a peak waveform, and the ratio of the half width of the peak waveform to the peak value is less than 1.0×10 ⁻⁶ .

In one embodiment, the ratio of the half-width to the peak value of the peak waveform is 0.3×10 ⁻⁶ or less.

In one embodiment, the ratio of the half-width to the peak value of the peak waveform is 0.1×10 ⁻⁶ or less.

In one embodiment, the particles exhibit a porosity of 75 or more.

In one embodiment, the particles exhibit a porosity of 80 or more.

In one embodiment, the particles exhibit a porosity of 85 or more.

In some embodiments, the electrolytic material includes lithium ions.

In one embodiment, the support supports an alkali metal component.

In one embodiment, the support supports a catalyst.

In one embodiment, the carrier supports a surfactant.

In some embodiments, the electrolytic material includes an ionomer.

In one embodiment, the support includes a carbon material.

In some embodiments, the support includes activated carbon.

An electrochemical device according to the present invention includes the above structure.

The evaluation support method according to the present invention supports the work of evaluating a structure. The structure includes an electrolytic material and a carrier supporting the electrolytic material. The carrier includes a plurality of particles, and each of the plurality of particles has pores. The evaluation support method includes the steps of collecting the particles from the support, measuring the volume magnetic susceptibility of the particles, and creating a graph showing the ratio of the number of particles to the volume magnetic susceptibility. include.

In one embodiment, the method for supporting evaluation of a structure further includes the step of measuring the porosity of the particles from the volume magnetic susceptibility of the particles.

According to the present invention, the performance of an electrochemical device can be improved.

(a) is a diagram showing the configuration of a lithium ion capacitor according to an embodiment of the present invention. (b) is a diagram showing the configuration of a fuel cell according to an embodiment of the present invention. 1 is a schematic diagram of an analysis device according to an embodiment of the present invention. FIG. 3 is a diagram showing the movement of particles according to an embodiment of the present invention. 1 is a diagram showing the configuration of an analysis device according to an embodiment of the present invention. 3 is a flowchart illustrating a structure evaluation support method according to an embodiment of the present invention. 3 is a diagram showing a bar graph of Example 1. FIG. FIG. 7 is a diagram showing a bar graph of Example 2. 3 is a diagram showing a bar graph of Comparative Example 1. FIG. 3 is a diagram showing a particle number graph of Example 1. FIG. 3 is a diagram showing a particle number graph of Example 2. FIG. 3 is a diagram showing a particle number graph of Comparative Example 1. FIG. 3 is a diagram showing particle number graphs of Example 3 and Comparative Example 2. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a structure, an electrochemical device, and an evaluation support method according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments. In the drawings, the same or corresponding parts are given the same reference numerals and the description will not be repeated.

[Structure]
The structure according to this embodiment includes an electrolytic material and a carrier. The electrolytic material is typically an electrolyte or an ionomer. The structure according to this embodiment is used for a positive electrode of a lithium ion capacitor, or a positive electrode and a negative electrode of an electric double layer capacitor. Alternatively, the structure according to this embodiment is used in a catalyst layer of a fuel cell.

The carrier according to this embodiment includes a plurality of particles, and each of the plurality of particles has pores. Specifically, when the structure according to the present embodiment is used for a positive electrode of a lithium ion capacitor or a positive electrode and a negative electrode of an electric double layer capacitor, the support may be made of a porous carbon material such as activated carbon. include. Further, when the structure according to the present embodiment is used in a catalyst layer of a fuel cell, the carrier includes a porous carbon material such as carbon black (secondary particles).

The carrier according to this embodiment supports an electrolytic material. Specifically, the electrolytic material is supported by the electrolytic material by entering into the pores formed on the surface of each particle included in the carrier or into the gaps between the particles included in the carrier. Further, the electrolytic material is covered by the electrolytic material on the surface of each particle included in the carrier, so that the electrolytic material is supported by the carrier.

In the structure according to this embodiment, when the volume magnetic susceptibility of each particle collected from the carrier is measured, the graph showing the ratio of the number of particles to the volume magnetic susceptibility includes a significant peak waveform. Further, the ratio of the half width of the peak waveform to the peak value is less than 1.0×10 ⁻⁶ . Hereinafter, a graph showing the ratio of the number of particles to the volume magnetic susceptibility may be referred to as a "particle number graph". Furthermore, the value of the ratio between the half-width of the peak waveform and the peak value may be referred to as the "value of the ratio of the peak waveform." The value of the peak waveform ratio is calculated by the following equation (1).
Ratio value = half width/peak value...(1)

The fact that the value of the peak waveform ratio is within a specific range indicates that the amount of electrolytic material supported on the particles collected from the support is evenly large. Specifically, when the amount of electrolytic material supported is small, the particle number graph does not include a significant peak waveform and becomes a broad waveform due to variations in volume magnetic susceptibility, that is, variations in the amount of electrolytic material supported. . The variation in volume magnetic susceptibility also depends on the variation in particle size. On the other hand, if the value of the ratio of peak waveforms falls within a specific range, that is, if the particle number graph includes a significant peak waveform, it means that there is little variation in volume magnetic susceptibility, that is, variation in the amount of electrolytic material supported. It shows that there are few. This is because when the amount of supported electrolytic material is large, the contribution of the volume magnetic susceptibility of the electrolytic material to the volume magnetic susceptibility of the particles increases.

According to the structure according to the present embodiment, the ratio of the half width of the peak waveform to the peak value is less than 1.0×10 ⁻⁶ . This indicates that the amount of electrolytic material supported by the carrier is evenly large. Therefore, the structure according to this embodiment can improve the characteristics of an electrochemical device. Specifically, when the structure according to this embodiment is used as a positive electrode of a lithium ion capacitor, the capacitance of the lithium ion capacitor can be increased. Similarly, when the structure according to this embodiment is used as the positive electrode and negative electrode of an electric double layer capacitor, the capacitance of the electric double layer capacitor can be increased. Further, when the structure according to this embodiment is used in a catalyst layer of a fuel cell, the current density of the fuel cell can be increased.

Note that the value of the peak waveform ratio is preferably 0.3×10 ⁻⁶ or less, more preferably 0.1×10 ⁻⁶ or less. The peak waveform ratio value being 0.3×10 ^-6 or less indicates that the variation in volume magnetic susceptibility is smaller, and the peak waveform ratio value being 0.1×10 ^-6 or less. indicates that the variation in volume magnetic susceptibility is even smaller. The smaller the variation in volume magnetic susceptibility, the more the amount of electrolytic material supported by the carrier increases, and the characteristics of the electrochemical device can be further improved.

Further, in the structure according to the present embodiment, it is preferable that each particle collected from the carrier has a porosity of 75 or more. When the porosity is 75 or more, there is a high possibility that the amount of electrolytic material supported will increase. The porosity is more preferably 80 or more, and even more preferably 85 or more. The higher the porosity, the higher the possibility that the amount of electrolytic material supported will increase.

The porosity is measured by dispersing each particle collected from the support in a medium such as a solvent. Specifically, porosity is the average of the volume (%) of electrolytic material that has entered each particle taken from the support and the volume (%) of medium that has entered each particle at the time of porosity measurement. Show value. The volume (%) of the electrolytic material indicates the ratio of the volume of the electrolytic material (volume of the electrolytic material that has entered the particles) to the volume of the particles. The volume of medium (%) indicates the ratio of the volume of medium (volume of medium that has entered the particle) to the volume of the particle. The total volume of the electrolytic material volume and the medium volume includes the volume of the electrolytic material and medium that has entered the pores of the particles. When the particles are aggregates, the total volume of the electrolytic material and the medium is the sum of the volume of the electrolytic material and medium that has entered the pores of each particle that makes up the aggregate, and the volume of each particle that makes up the aggregate. volume of intervening electrolytic material and media.

The porosity P is calculated based on the following formula.
P=(Vc+Vm)/Vp=(Vc+Vm)/(Vb+Vc+Vm)

In the above formula, Vc represents the volume of the electrolytic material, Vm represents the volume of the medium, Vp represents the volume of the particle, and Vb represents the volume of the main body portion of the particle. The volume Vb of the main body portion of the particle indicates the volume of the particle without electrolytic material and medium. When the particle to be measured is an aggregate, the volume Vb of the main body portion of the particle indicates the total value of the volumes of the main body portions of each particle constituting the aggregate.

Alternatively, when the electrolytic material and the medium are the same material, the porosity P may be calculated based on the following formula, assuming that the volume Vc of the electrolytic material is included in the volume Vm of the medium. In other words, the volume (%) of the medium may be used as the porosity P.
P=Vm/Vp

[Electrochemical device]
Next, with reference to FIGS. 1(a) and 1(b), an electrochemical device according to this embodiment will be described using a lithium ion capacitor and a fuel cell as examples. Although the structure of the negative electrode of electric double layer capacitors is different from that of lithium ion capacitors, the structure of other parts is similar to that of lithium ion capacitors, and the structure of the negative electrode of electric double layer capacitors is similar to that of lithium ion capacitors. The structure is similar to that of the positive electrode. Therefore, a description of the electric double layer capacitor will be omitted.

[Lithium ion capacitor]
FIG. 1(a) is a diagram showing the configuration of a lithium ion capacitor 10 according to this embodiment. As shown in FIG. 1(a), the lithium ion capacitor 10 includes a positive electrode 20, a negative electrode 30, and a separator 40.

The positive electrode 20 includes a current collector 21 and an electrode layer 22. Electrode layer 22 is formed on the surface of current collector 21 . The electrode layer 22 includes a porous carbon material and adsorbs and desorbs anions and cations. The carbon material is not particularly limited as long as it is porous, and may be, for example, activated carbon, carbon fiber, graphene, or carbon nanotubes. Specifically, the electrode layer 22 may contain a carbon material, a binder, a conductive aid, and the like. The electrode layer 22 is formed on the surface of the current collector 21 by applying a paste prepared by mixing a carbon material, a binder, a conductive additive, etc. to the surface of the current collector 21 .

The negative electrode 30 includes a current collector 31 and an electrode layer 32. Electrode layer 32 is formed on the surface of current collector 31 . The electrode layer 32 includes an electrode active material that can reversibly insert and release lithium ions. Specifically, the electrode layer 32 may contain an electrode active material, a binder, a conductive aid, and the like. It is preferable to use a carbon material as the electrode active material. The electrode layer 32 is formed by coating the surface of the current collector 31 with a paste prepared by mixing an electrode active material, a binder, a conductive aid, etc., and then causing the electrode active material to carry lithium ions through a pre-doping process. As a result, it is formed on the surface of the current collector 31.

Separator 40 is arranged between positive electrode 20 and negative electrode 30. Generally, separator 40 is adjacent to electrode layer 22 of positive electrode 20 and electrode layer 32 of negative electrode 30. The lithium ion capacitor 10 has a configuration in which a positive electrode 20, a negative electrode 30, and a separator 40 are immersed in an electrolytic solution. The electrolytic solution is not particularly limited as long as it contains lithium ions, but a non-aqueous organic electrolytic solution in which a lithium salt is dissolved is preferable.

When the electrode layer 22 of the positive electrode 20 includes activated carbon produced by an alkali activation method, the carbon material (supporting body) of the electrode layer 22 may further support an alkali metal component. For example, when potassium hydroxide or sodium hydroxide is used in the activation treatment, potassium ions or sodium ions may be supported by the carbon material (support) of the electrode layer 22.

In the lithium ion capacitor 10 according to the present embodiment, the electrode layer 22 of the positive electrode 20 is an example of the structure of the present invention, and the carbon material of the electrode layer 22 of the positive electrode 20 is an example of the support of the present invention. Specifically, the carbon material of the electrode layer 22 is porous, and the electrolytic solution that has entered the pores is supported by the carbon material. Further, the electrolytic solution that has entered between the carbon materials included in the electrode layer 22 is supported by the carbon materials.

[Fuel cell]
FIG. 1(b) is a diagram showing the configuration of a fuel cell 50 according to this embodiment. Specifically, FIG. 1(b) shows the configuration of the polymer electrolyte fuel cell according to this embodiment. As shown in FIG. 1(b), the fuel cell 50 includes a separator 51, a gas diffusion layer 52, an anode electrode catalyst layer 53 (fuel electrode), a solid polymer electrolyte membrane 54, and a cathode electrode catalyst layer 55 (air electrode). Equipped with

The catalyst layers 53 and 55 include a carbon material supporting an ionomer and a catalyst. The carbon material is not particularly limited as long as it is porous, and may be, for example, carbon black such as acetylene black, activated carbon, carbon fiber, graphene, or carbon nanotubes. The catalyst is not particularly limited as long as it causes a cell reaction at the fuel electrode and air electrode of the fuel cell, but platinum or a transition metal is preferable.

In this embodiment, the carbon material of the catalyst layers 53 and 55 supports an ionomer as an electrolytic material. The ionomer covers the surface of the carbon material and functions as a conductive path.

The carbon material of the catalyst layers 53 and 55 may further support a surfactant. By supporting the surfactant on the carbon material, the ionomer and the catalyst can easily enter into the pores of the carbon material. The surfactant is not particularly limited, and various nonionic surfactants such as ester type, ether type, and ester/ether type can be used.

In the fuel cell 50 according to the present embodiment, the catalyst layers 53 and 55 are an example of the structure of the present invention, and the carbon material of the catalyst layers 53 and 55 is an example of the support of the present invention. Specifically, the carbon material of the catalyst layers 53 and 55 is porous, and the ionomer that has entered the pores is supported by the carbon material. Further, an ionomer covering the surface of the carbon material is supported by the carbon material.

Note that the structure according to this embodiment is not only used for the positive electrode of a lithium ion capacitor, the positive electrode and negative electrode of an electric double layer capacitor, and the catalyst layer of a fuel cell, but also for use in a plurality of particles (supported) having pores. It can be used for various electrode members as long as the structure supports an electrolytic material.

[Analysis equipment]
Next, the analysis device 100 according to this embodiment will be described with reference to FIGS. 2 to 4. The analyzer 100 according to this embodiment measures the volume magnetic susceptibility and porosity of individual particles.

FIG. 2 is a schematic diagram of the analysis device 100 according to this embodiment. In this embodiment, the analyzer 100 measures the volume magnetic susceptibility and porosity of each particle collected from an electrode member of an electrochemical device. The analysis device 100 includes a magnetic field generation section 200, an observation section 300, and an information processing section 400. A cell 201 is arranged near the magnetic field generation section 200.

The magnetic field generation unit 200 generates a magnetic field to cause the particles p in the cell 201 to magnetophorese. The observation unit 300 observes the particles p within the cell 201. The information processing unit 400 measures the particle diameter and magnetophoretic velocity of the particle p based on the observation result by the observation unit 300, and measures the volume magnetic susceptibility of the particle p based on the measured particle diameter and magnetophoretic velocity. Furthermore, the information processing unit 400 measures the porosity of the particles p based on the volume magnetic susceptibility of the particles p. Furthermore, the information processing unit 400 creates a graph (particle number graph) showing the ratio of the number of particles to the volume magnetic susceptibility. The analyzer 100 will be explained in more detail below.

The magnetic field generation unit 200 generates a magnetic field gradient (magnetic flux density gradient) and causes a magnetic force to act on the particles p within the cell 201. As a result, the particles p undergo magnetophoresis. In this embodiment, the magnetic field generation unit 200 includes a pair of permanent magnets that generate a magnetic field gradient. The two permanent magnets constituting the pair of permanent magnets are arranged with a gap of a certain distance of, for example, 100 μm or more and 500 μm or less. Cell 201 is placed in the air gap between two permanent magnets.

In this embodiment, cell 201 is a capillary tube. The material of the cell 201 is not particularly limited as long as it can transmit visible light or laser light. For example, cell 201 may be made of glass or plastic.

Particles p are present in medium m. One particle p may exist in the medium m, or a plurality of particles p may exist in the medium m. When a plurality of particles p exist in the medium m, the plurality of particles p may be dispersed in the medium m or may be unevenly distributed in the medium m. The medium m may be a liquid or a gas. Medium m can be, for example, propylene carbonate or acetonitrile. Alternatively, medium m may be air, for example. Note that the medium m may or may not contain a component of an electrolytic material, that is, a component of an ionomer or a component of an electrolytic solution.

Particles p are introduced into cell 201 together with medium m, for example by a microsyringe, a micropump, or an autosampler. Alternatively, the particles p can be introduced into the cell 201 together with the medium m based on the siphon principle. Alternatively, a droplet containing particles p may be introduced into the cell 201 (capillary tube) by capillary action. When a droplet containing particles p is dropped onto one end of the capillary tube, the droplet flows through the capillary tube due to capillary action.

The observation unit 300 observes the particles p in the cell 201 and generates a signal indicating the observation result. The information processing unit 400 measures the particle diameter and magnetophoretic velocity of the particle p based on the signal generated by the observation unit 300. The information processing unit 400 includes a storage device 401, a processing device 402, and a display device 403. Information processing unit 400 is typically a general-purpose computer such as a personal computer.

The storage device 401 stores programs, setting information, and the like. The storage device 401 may be configured by, for example, a storage device and a semiconductor memory. The storage device is, for example, an HDD (Hard Disk Drive). The storage device 401 may include, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory) as a semiconductor memory.

The processing device 402 performs various processes such as numerical calculation, information processing, and device control by executing programs stored in the storage device 401. The processing device 402 is configured by, for example, a processor such as a CPU (Central Processing Unit).

The display device 403 includes a display such as a liquid crystal display or an organic EL display. The display device 403 is controlled by the processing device 402 and displays various images and various screens. In this embodiment, the display device 403 displays a particle number graph.

The processing device 402 acquires the temporal change in the position of the particle p within the cell 201 from the observation result of the observation unit 300. For example, the processing device 402 measures the position of the particle p within the cell 201 at predetermined time intervals. In other words, the position of the particle p at different times is measured. The processing device 402 measures the magnetophoretic velocity of the particle p based on the temporal change in the position of the particle p.

Furthermore, the processing device 402 measures the particle diameter of the particle p from the signal generated by the observation unit 300. The processing device 402 further measures the volume magnetic susceptibility of the particles p based on the particle size and magnetophoretic velocity of the particles p.

For example, the processing device 402 calculates the volume magnetic susceptibility of the particle p based on the following equation (2).
v={2(χp-χm)r ² /9ημ _o }B(dB/dx)...(2)

In equation (2), v is the magnetophoretic velocity of particle p, χp is the volume magnetic susceptibility of particle p, χm is the volume magnetic susceptibility of medium m, r is the radius of particle p, and η is is the viscosity of the medium m, μ _o is the vacuum permeability, B is the magnetic flux density, and dB/dx is the magnetic field gradient (gradient of the magnetic flux density). Note that equation (2) is derived from the fact that the difference in magnetic force that the particle p and the medium m receive in the axial direction (x direction) of the cell 201 (capillary tube) is approximately equal to the viscous resistance force.

Note that the magnetophoretic velocity v and bulk magnetic susceptibility χp of the particles p are measured values measured by the processing device 402. The radius r of the particle p is calculated by the processing device 402 from the measured particle diameter of the particle p, for example. The volume magnetic susceptibility χm of the medium m, the viscosity η of the medium m, the vacuum magnetic permeability μ _o , the magnetic flux density B, and the magnetic field gradient dB/dx are stored in the storage device 401 in advance. For example, an analyst operates an input device such as a keyboard, a mouse, or a touch display to obtain the volume magnetic susceptibility χm of the medium m, the viscosity η of the medium m, the vacuum permeability μ _o , the magnetic flux density B, and the magnetic field. The slope dB/dx can be stored in the storage device 401. The volume magnetic susceptibility χm of the medium m, the viscosity η of the medium m, and the vacuum permeability μ _o are, for example, literature values. The magnetic flux density B and the magnetic field gradient dB/dx are, for example, measured values.

When the processing device 402 measures the volume magnetic susceptibility of each particle collected from the electrode member of the electrochemical device, the processing device 402 causes the storage device 401 to store data indicating the measurement results. The processing device 402 creates a particle number graph based on the data indicating the measurement results, and causes the display device 403 to display the graph.

The processing device 402 further measures the porosity of each particle taken from the electrode member of the electrochemical device. Specifically, particles collected from an electrode member of an electrochemical device carry an electrolytic material. When measuring the porosity, prepare particles of the same type as the particles collected from the electrode member of the electrochemical device. In other words, particles not carrying an electrolytic material are prepared. In addition to measuring the volume magnetic susceptibility and particle size of particles collected from the electrode member of the electrochemical device, the volume magnetic susceptibility and particle size of particles not carrying an electrolytic material are measured.

When the porous particles p, that is, the particles p having pores, do not support an electrolytic material, they can be divided into a main body portion b and a void portion s1. In this case, the volume (%) of the void portion s1 can be expressed by the following equation (3).
P1=Vs1/Vp=Vs1/(Vb+Vs1)...(3)

In equation (3), P1 is the volume (%) of the void portion s1 of the particle p, Vs1 is the volume of the void portion s1 of the particle p, Vp is the volume of the particle p, and Vb is the main body of the particle p. This is the volume of part b. The volume Vp of the particle p can be expressed as the sum of the volume of the main body portion b of the particle p and the volume of the void portion s1 of the particle p, as shown in equation (4) below. Note that when the particle p is an aggregate, the volume Vs1 of the void portion s1 of the particle p is the sum of the volumes of pores formed in each particle constituting the aggregate and each particle constituting the aggregate. It shows the total value of the volume of the gap between.
Vp=Vb+Vs1...(4)

When the gap s1 of the particle p is filled with the medium m, the relationship between the product of the volume magnetic susceptibility and the volume is expressed by the following equation (5).
χpVp=χbVb+χmVs1...(5)

In equation (5), χp is the volume magnetic susceptibility of the particle p, χb is the volume magnetic susceptibility of the main body portion b of the particle p, and χm is the volume magnetic susceptibility of the medium m. In addition, when the particle p is an aggregate, the volume magnetic susceptibility of the main body part of the particle p shows the volume magnetic susceptibility of the main body part of the particle|grains which constitute an aggregate.

Based on the above equations (3) to (5), equation (3) can be converted into the following equation (6). In this embodiment, the processing device 402 measures the volume (%) of the void portion s1 of the particle p based on the following equation (6). In other words, the processing device 402 measures the volume (%) of the medium that has entered the particles p. When the processing device 402 measures the volume (%) of the void portion s1 of the particle p, the processing device 402 causes the storage device 401 to store data indicating the measurement result.
P1=(χp-χb)/(χm-χb)...(6)

Note that the volume magnetic susceptibility χp of the particle p is a measurement value measured by the processing device 402. The volume magnetic susceptibility χb of the main body portion b of the particle p and the volume magnetic susceptibility χm of the medium m are stored in advance in the storage device 401. For example, the analyst can cause the storage device 401 to store the volume magnetic susceptibility χb of the body portion b of the particle p and the volume magnetic susceptibility χm of the medium m by operating the input device. The volume magnetic susceptibility χb of the main body portion b of the particle p and the volume magnetic susceptibility χm of the medium m are, for example, literature values.

Further, from the above equation (3), the volume Vs1 of the void portion s1 of the particle p, that is, the volume Vm1 of the medium m that has entered the particle p can be expressed by the following equation (7).
Vm1=Vs1=P1×Vp...(7)

Therefore, the above equation (4) can be converted into the following equation (8).
Vp=Vb+Vs1=Vb+P1×Vp...(8)

Therefore, the volume Vb of the main body portion b of the particle p can be expressed by the following equation (9).
Vb=Vp-Vs1=Vp-P1×Vp...(9)

The processing device 402 measures the volume Vb of the main body portion b of the particle p based on the above equation (9), and stores data indicating the measurement result in the storage device 401. Alternatively, the analyst calculates the volume Vb of the main body portion b of the particle p based on the above equation (9). In this case, the analyst operates the input device to store data indicating the calculated volume Vb in the storage device 401. Note that the volume Vp of the particles p can be calculated by the analyst from the particle diameter of the particles p measured by the processing device 402. In this case, the analyst operates the input device to store data indicating the calculated volume Vp in the storage device 401. Alternatively, the processing device 402 may measure the volume Vp of the particle p based on the particle diameter of the particle p. In this case, the processing device 402 causes the storage device 401 to store data indicating the measurement results.

On the other hand, when the porous particles p support an electrolytic material, the particles p can be divided into a main body part b, a void part s2, and the supported electrolytic material. In this case, the volume (%) of the void portion s2 can be expressed by the following equation (10).
P2=Vs2/Vp=Vs2/(Vb+Vs2+Vc)...(10)

In equation (10), P2 is the volume (%) of the void portion s2 of the particle p, Vs2 is the volume of the void portion s2 of the particle p, Vp is the volume of the particle p, and Vb is the main body of the particle p. is the volume of part b, and Vc is the volume of the electrolytic material supported on particles p. The volume Vp of the particle p is determined by the volume of the main body part b of the particle p, the volume of the void part s2 of the particle p, and the volume of the electrolytic material supported on the particle p, as shown in the following equation (11). It can be expressed as a sum. Note that when the particle p is an aggregate, the volume Vs of the void portion s2 of the particle p is determined by the sum of the volumes of pores formed in each particle constituting the aggregate and each particle constituting the aggregate. It shows the total value of the volume of the gap between.
Vp=Vb+Vs2+Vc...(11)

When the void portion s2 of the particle p is filled with the medium m, the relationship between the product of the volume magnetic susceptibility and the volume is expressed by the following equation (12).
χpVp=χbVb+χmVs2+χcVc...(12)

In equation (12), χp is the volume magnetic susceptibility of the particle p, χb is the volume magnetic susceptibility of the main body part b of the particle p, χm is the volume magnetic susceptibility of the medium m, and χc is the volume magnetization of the electrolytic material. rate. In addition, when the particle p is an aggregate, the volume magnetic susceptibility of the main body part of the particle p shows the volume magnetic susceptibility of the main body part of the particle|grains which constitute an aggregate.

Based on the above equations (10) to (12), equation (10) can be converted to the following equation (13). In this embodiment, the processing device 402 measures the volume (%) of the void portion s2 of the particle p based on the following equation (13). In other words, the processing device 402 measures the volume (%) of the medium that has entered the particles p.
P2=(χc-χp)/(χc-χm)-(χc-χb)×Vb/((χc-χm)×Vp)...(13)

Note that the volume magnetic susceptibility χp of the particle p is a measurement value measured by the processing device 402. The volume magnetic susceptibility χc of the electrolytic material, the volume magnetic susceptibility χm of the medium m, and the volume magnetic susceptibility χb of the main body portion b of the particle p are stored in advance in the storage device 401. For example, the analyst may store the volume magnetic susceptibility χc of the electrolytic material, the volume magnetic susceptibility χm of the medium m, and the volume magnetic susceptibility χb of the body portion b of the particle p in the storage device 401 by operating the input device. can. The volume magnetic susceptibility χc of the electrolytic material, the volume magnetic susceptibility χm of the medium m, and the volume magnetic susceptibility χb of the main body portion b of the particle p are, for example, literature values. The volume Vb of the main body portion of the particle p is a value measured or calculated based on the above equation (9), and is stored in the storage device 401. The volume Vp of the particle p can be calculated by the analyst from the particle diameter of the particle p measured by the processing device 402. In this case, the analyst operates the input device to store data indicating the calculated volume Vp in the storage device 401. Alternatively, the processing device 402 may measure the volume Vp of the particle p based on the particle diameter of the particle p. In this case, the processing device 402 causes the storage device 401 to store data indicating the measurement results.

Further, from the above equation (10), the volume Vs2 of the void portion s2 of the particle p, that is, the volume Vm2 of the medium that has entered the particle p, can be expressed by the following equation (14). The processing device 402 measures the volume Vm2 of the medium based on the following equation (14), and stores data indicating the measurement result in the storage device 401. Alternatively, the analyst may calculate the volume Vm2 of the medium based on the following equation (14). In this case, the analyst operates the input device to store data indicating the calculated volume Vm2 in the storage device 401.
Vm2=Vs2=P2×Vp...(14)

Further, the above equation (11) can be converted into the following equation (15) based on the above equation (14).
Vp=Vb+Vs2+Vc=Vb+P2×Vp+Vc...(15)

Therefore, the volume Vc of the electrolytic material supported on the particles p can be expressed by the following equation (16).
Vc=Vp-Vb-Vs2=Vp-Vb-P2×Vp...(16)

The processing device 402 measures the volume Vc of the electrolytic material supported on the particles p based on the above equation (16), and stores data indicating the measurement result in the storage device 401. Alternatively, the analyst may calculate the volume Vc of the electrolytic material supported on the particles p based on the above equation (16). In this case, the analyst operates the input device to store data indicating the calculated volume Vc in the storage device 401.

The processing device 402 uses the volume Vp of the particles p (the volume of the particles collected from the electrode member of the electrochemical device) stored in the storage device 401, the volume Vm2 of the medium, and the volume Vc of the electrolytic material to form the following equation. The porosity P is measured based on (17).
P=(Vc+Vm2)/Vp...(17)

After measuring the porosity P, the processing device 402 causes the storage device 401 to store data indicating the measurement result. The processing device 402 causes the display device 403 to display data indicating the porosity P based on the data indicating the measurement results.

Note that when the electrolytic material and the medium are the same material, the processing device 402 determines the void space based on the above formula (6) with reference to the volume magnetic susceptibility measured from each particle collected from the electrode member of the electrochemical device. The ratio P (volume (%) of medium) may be measured.

Next, the movement of the particle p will be explained with reference to FIGS. 3(a) and 3(b). FIGS. 3(a) and 3(b) are diagrams showing the movement of the particle p. Specifically, FIGS. 3(a) and 3(b) show the relationship between the volume magnetic susceptibility of the particle p and the medium m and the moving direction of the particle p. As shown in FIGS. 3A and 3B, the magnetic field generation unit 200 includes a permanent magnet 200a with a north magnetic pole and a permanent magnet 200b with a south magnetic pole. The two permanent magnets 200a and 200b face each other with the cell 201 in between.

As shown in FIG. 3A, when the volume magnetic susceptibility of the particle p is smaller than the volume magnetic susceptibility of the medium m, the particle p moves in a direction away from the magnetic field (magnetic field generation unit 200). On the other hand, as shown in FIG. 3B, when the volume magnetic susceptibility of the particle p is larger than the volume magnetic susceptibility of the medium m, the particle p moves in a direction approaching the magnetic field (magnetic field generation unit 200).

As shown in FIGS. 3(a) and 3(b), the movement of the particle p is determined according to the volume magnetic susceptibility of the particle p and the medium m. Note that the particles p receive a force near the ends of the permanent magnets 200a and 200b. For example, the particle p receives a force within a range of about ±200 μm from the vicinity of the ends of the permanent magnets 200a and 200b.

Next, with reference to FIG. 4, the analysis device 100 will be further described. FIG. 4 is a diagram showing the configuration of the analysis device 100. As shown in FIG. 4, the analysis device 100 further includes a light source 500. Furthermore, the observation section 300 includes an enlarging section 301 and an imaging section 302.

The light source 500 emits relatively high-intensity light that includes a visible light component. The light source 500 irradiates the cell 201 with light. As a result, the particles p are irradiated with light. The wavelength spectrum of the light emitted from the light source 500 may be relatively broad. As the light source 500, for example, a halogen lamp is preferably used.

The particles p introduced into the cell 201 are enlarged by an appropriate magnification by the enlarging section 301 and imaged by the imaging section 302. The position of the particle p can be specified from the imaging result of the imaging unit 302 (the image captured by the imaging unit 302). For example, the magnifying unit 301 includes an objective lens, and the imaging unit 302 includes a charge coupled device (CCD). Alternatively, each pixel of the imaging unit 302 may be configured with a photodiode or a photomultiplier tube. The imaging unit 302 images the particles p at predetermined time intervals, for example. Note that the imaging unit 302 may image the light emitted from the light source 500 and transmitted through the cell 201, or may image the light emitted from the light source 500 and scattered by the particles p.

The information processing unit 400 (processing device 402) acquires the temporal change in the position of the particle p from the imaging result of the imaging unit 302, and measures the magnetophoretic velocity of the particle p from the temporal change in the position of the particle p. do.

Further, the information processing unit 400 (processing device 402) measures the particle diameter of the particle p based on the imaging result of the particle p. For example, the information processing unit 400 (processing device 402) executes the following processing. That is, first, the image captured by the imaging unit 302 is converted into a monochrome image, and its brightness is converted into a numerical value. Next, the boundary of the particle p is set by comparing the differential value of the brightness value with a threshold value. Next, the area of the particle p is detected from the set boundary, and the particle diameter is determined from the radius of the circle corresponding to the area. Alternatively, the center of particle p is defined, a plurality of straight lines passing through the center of particle p are drawn, and the average distance between two points intersecting the boundary of particle p in each straight line is determined.

[Evaluation support method]
Next, with reference to FIG. 5, a structure evaluation support method according to the present embodiment will be described. FIG. 5 is a flowchart showing the structure evaluation support method according to this embodiment. The evaluation support method according to this embodiment can be executed using the analysis device 100 described with reference to FIGS. 2 to 4.

As shown in FIG. 5, first, particles p1 are collected from the carrier of the structure (step S1). Specifically, particles p1 are collected from an electrode member of an electrochemical device. Specifically, a part of the electrode member is scraped off, and the scraped part of the electrode member is crushed to obtain particles p1. For example, when the electrochemical device is a lithium ion capacitor, particles p1 are collected from the positive electrode layer. When the electrochemical device is an electric double layer capacitor, particles p1 are collected from the positive electrode layer or the negative electrode layer. When the electrochemical device is a fuel cell, particles p1 are collected from the catalyst layer.

Next, the magnetophoretic particles p1 are observed, and the magnetophoretic velocity and particle diameter of the particles p1 are measured from the observation results (step S2). Next, the volume magnetic susceptibility of the particle p1 is measured based on the measured magnetophoretic velocity and particle diameter of the particle p1 (step S3).

Next, the porosity of the particles p1 is measured based on the measured volume magnetic susceptibility of the particles p1 (step S4). For example, a particle p2 of the same type as the particle p1 is prepared, and the particle diameter and volume magnetic susceptibility of the particle p2 are measured in the same manner as in step S2 and step S3. Next, the volume of the main body portion of the particle p2 is measured based on the measured volume magnetic susceptibility and particle diameter of the particle p2. Furthermore, based on the volume magnetic susceptibility of the particle p1, the particle diameter of the particle p1, and the volume of the main body part of the particle p2, the volume of the particle p1, the volume of the electrolytic material supported on the particle p1, and the volume of the electrolytic material that has entered the particle p1 are determined. Measure the volume of the medium. Next, the porosity P of the particles p1 is measured with reference to the volume of the particles p1, the volume of the electrolytic material, and the volume of the medium.

Next, based on the measured volume magnetic susceptibility of the particles p1, a graph (particle number graph) showing the ratio of the number of particles p1 to the volume magnetic susceptibility is created (step S5).

The analyst determines whether the created particle number graph includes a significant peak waveform. When a significant peak waveform is included in the graph, the analyst obtains the ratio value between the half width of the peak waveform and the peak value (the value of the ratio of the peak waveform) from the graph. Then, the analyst evaluates the structure based on whether the value of the peak waveform ratio falls within a specific range.

In addition, in this embodiment, the particle number graph was created after measuring the porosity, but the particle number graph may be created before measuring the porosity. Furthermore, in the present embodiment, the analyst obtains the value of the ratio of peak waveforms, but the information processing unit 400 determines whether or not the particle number graph includes a significant peak waveform. When included in the graph, the value of the peak waveform ratio may be calculated and the calculation result may be displayed on the display device 403. Furthermore, the information processing unit 400 may determine whether the value of the ratio of the peak waveform is included in a specific range, and display the determination result on the display device 403.

The embodiments of the present invention have been described above with reference to the drawings (FIGS. 1 to 5). According to this embodiment, the characteristics of an electrochemical device can be improved. Note that the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof.

For example, in the embodiment of the present invention, the particle number graph is displayed on the display device 403, but the particle number graph may be printed. Similarly, the porosity measurement results may be printed.

Further, in the embodiment of the present invention, the porosity was measured, but the measurement of the porosity may be omitted.

Further, in the embodiment of the present invention, the magnetic field generation unit 200 includes a pair of permanent magnets 200a and 200b, but the magnetic field generation unit 200 includes a pair of magnetic pole pieces to generate a magnetic field gradient. Good too. Alternatively, the magnetic field generation unit 200 may include an electromagnet, a magnetic circuit, or a superconducting magnet to generate a magnetic field gradient. When the magnetic field generation unit 200 includes a pair of magnetic pole pieces, the two magnetic pole pieces constituting the pair of magnetic pole pieces are arranged with a gap of a certain distance of, for example, 100 μm or more and 500 μm or less. Cell 201 is placed in the air gap between the two pole pieces. The pole piece may be, for example, a magnetized piece of iron. The piece of iron can be magnetized, for example, by a permanent magnet, an electromagnet, a magnetic circuit, or a superconducting magnet.

Further, in the embodiment of the present invention, the cell 201 is a capillary tube, but the cell 201 may be a glass cell or a plastic cell. The glass cell and the plastic cell have a recess that holds a medium m containing particles p. Alternatively, glass cells and plastic cells have channels through which medium m containing particles p flows. When the cell 201 is a glass cell or a plastic cell having a microchannel, when a droplet containing particles p is dropped onto one end of the microchannel, the droplet flows through the microchannel due to capillary action.

Further, in the embodiment of the present invention, the analyzer 100 includes the light source 500, but the analyzer 100 may include a laser instead of the light source 500, or may further include a laser in addition to the light source 500. . When the analyzer 100 includes a light source 500 and a laser, when emitting light from the light source 500, the emission of laser light from the laser is stopped, and when emitting laser light from the laser, the emission of laser light from the light source 500 is stopped. Stops light emission. When using a laser, the particles p introduced into the cell 201 are irradiated with laser light. The imaging unit 302 images the laser light (scattered light) scattered by the particles p via the enlarging unit 301.

When the particles p are irradiated with laser light, the capillary tube is preferably a square capillary whose cross section perpendicular to the axial direction is square. By using a square capillary, it is easy to give a mirror finish to the side surface of the cell 201 that is irradiated with laser light.

Further, in the embodiment of the present invention, the particle size of the particle p is obtained by image analysis, but the particle size of the particle p may be measured by analyzing the Brownian motion of the particle p. Specifically, the diffusion coefficient is determined from the variance of the change in position (displacement) of the particle p in the direction (y direction) orthogonal to the axial direction (x direction) of the capillary tube, and the particle diameter of the particle p is determined from this diffusion coefficient. You can ask for it. Alternatively, a laser may be used to obtain the particle size of the particles p, for example based on dynamic light scattering or static light scattering.

In the embodiment of the present invention, although the information processing unit 400 (processing device 402) measures the particle diameter of the particle p, the image captured by the imaging unit 302 is displayed on the display device 403, and the image captured by the imaging unit 302 is displayed on the display device 403. An analyst may measure the particle diameter of the particle p from the captured image. Alternatively, the image captured by the imaging unit 302 may be printed, and the analyst may measure the particle diameter of the particles p from the printed image.

Further, in the embodiment of the present invention, the imaging unit 302 acquires the magnetophoretic velocity of the particle p by imaging the particle p at predetermined time intervals. The magnetophoretic velocity of the particles p may be measured using the same method.

Further, in the embodiment of the present invention, the volume magnetic susceptibility of the particle p is obtained based on the measured value of the magnetophoretic velocity, but the volume magnetic susceptibility of the particle p may also be obtained using a SQUID element, a magnetic balance, etc. good.

Further, in the embodiment of the present invention, the information processing unit 400 measures the particle diameter, but literature values may be used for the particle diameter of the particles p.

Examples of the present invention will be described below. However, the present invention is not limited to the examples described below.

[Examples 1 and 2 and Comparative Example 1]
In this example, three types of activated carbon were prepared and three types of samples were produced. Specifically, a paste-like sample containing activated carbon, a binder, and a conductive aid as main components was prepared. Next, a paste sample was applied to the surface of the plate-like member to prepare an electrode plate, and the electrode plate was immersed in propylene carbonate, which is a simple substitute for an electrolytic solution. Aluminum foil having a plurality of through holes was used as the plate member. An acrylic polymer binder was used as the binder. Acetylene black was used as a conductive aid. Thereafter, the electrode plate was taken out from the propylene carbonate, a portion of the sample was scraped off, and the scraped portion of the sample was pulverized in a mortar. Then, a powdered sample is dispersed in a medium (propylene carbonate), a portion of the medium in which the sample is dispersed is taken out and introduced into a cell, and the volume magnetic susceptibility and porosity of each particle (the volume of the medium ( %)) was measured. Furthermore, the number of particles was measured for each volume magnetic susceptibility, a bar graph showing the ratio of the number of particles to the volume magnetic susceptibility (particle number %) was created, and a particle number graph was created from the bar graph. Note that one of the three types of samples is Comparative Example 1.

The maximum value of the magnetic field applied during the measurement was 2.7T. The distance between the N-pole permanent magnet and the S-pole permanent magnet was 0.4 mm. A square tubular cell made of glass was used as the cell. Specifically, the cross-sectional shape of the cell in the direction orthogonal to the axial direction was a square of 100 μm×100 μm. Propylene carbonate (volume magnetic susceptibility: -7.50×10 ⁻⁶ ) was used as the medium.

Table 1 shows the measurement results of the volume magnetic susceptibility and porosity of Example 1.

Table 2 shows the measurement results of the volume magnetic susceptibility and porosity of Example 2.

Table 3 shows the measurement results of the volume magnetic susceptibility and porosity of Comparative Example 1.

As is clear from Tables 1 and 2, the porosity of Example 1 was 85 or more. Moreover, the porosity of Example 2 was 80 or more. On the other hand, the porosity of Comparative Example 1 was not 75 or more.

FIG. 6 is a diagram showing a bar graph of Example 1. FIG. 7 is a diagram showing a bar graph of Example 2. FIG. 8 is a diagram showing a bar graph of Comparative Example 1. Moreover, FIG. 9 is a diagram showing a particle number graph of Example 1. FIG. 10 is a diagram showing a particle number graph of Example 2. FIG. 11 is a diagram showing a particle number graph of Comparative Example 1. In FIGS. 6 to 11, the vertical axis indicates the number of particles (%), and the horizontal axis indicates the volume magnetic susceptibility. Specifically, the particle number graph shown in FIG. 9 was obtained by connecting the vertices of each bar graph shown in FIG. 6 with line segments and smoothing the line segments. Similarly, particle number graphs shown in FIGS. 10 and 11 were obtained from the bar graphs shown in FIGS. 7 and 8.

Table 4 shows the half-width, particle number peak value (%), and peak waveform ratio value (value of the ratio between half-width and peak value) of Example 1, Example 2, and Comparative Example 1. The measurement results are shown below.

As shown in FIG. 9, the particle number graph of Example 1 included a significant peak waveform, and as shown in Table 4, the value of the ratio of the peak waveforms was approximately 0.06×10 ⁻⁶ . In addition, as shown in FIG. 10, the particle number graph of Example 2 also included a significant peak waveform, and as shown in Table 4, the value of the ratio of the peak waveforms was approximately 0.33×10 ^-6 . Therefore, the value of the peak waveform ratio in Example 1 was within the range of less than 1.0×10 ⁻⁶ . Similarly, the value of the peak waveform ratio in Example 2 was within the range of 0.3×10 ⁻⁶ or less. On the other hand, the particle number graph of Comparative Example 1 had a broad waveform, as shown in FIG. 11, and as shown in Table 4, the value of the ratio of the peak waveform was approximately 1.17×10 ⁻⁶ .

Further, as a result of manufacturing a lithium ion capacitor using the electrode plate coated with the sample of Example 1, the capacitance per unit weight was 78 [F]. Similarly, a lithium ion capacitor was manufactured using the electrode plate coated with the sample of Example 2, and the capacitance per unit weight was 56 [F]. As a result of manufacturing a lithium ion capacitor using the electrode plate coated with the sample of Comparative Example 1, the capacitance per unit weight was 53 [F]. Therefore, Examples 1 and 2 in which the peak waveform ratio value was less than 1.0×10 ⁻⁶ improved the performance of the lithium ion capacitor compared to Comparative Example 1.

[Example 3 and Comparative Example 2]
In Example 3, a sample was used in which carbon black was combined with 0.3% by mass of ionomer. In Comparative Example 2, carbon black was used as a sample. As in Examples 1 and 2 and Comparative Example 1, a powdered sample was dispersed in a medium, a portion of the medium in which the sample was dispersed was taken out and introduced into a cell, and the volume magnetic susceptibility of each particle was determined. It was measured. However, unlike Examples 1 and 2 and Comparative Example 1, water was used as the medium. Furthermore, the number of particles was measured for each volume magnetic susceptibility, a bar graph showing the ratio of the number of particles to the volume magnetic susceptibility (particle number %) was created, and a particle number graph was created from the bar graph.

Table 5 shows the measurement results of the half-width, the peak value (%) of the number of particles, and the ratio of the peak waveform (the ratio of the half-width to the peak value) of Example 3 and Comparative Example 2. .

FIG. 12 is a diagram showing particle number graphs of Example 3 and Comparative Example 2. In FIG. 12, the vertical axis shows the number of particles (%), and the horizontal axis shows the volume magnetic susceptibility. As shown in FIG. 12, the particle number graph of Example 3 included a significant peak waveform, and as shown in Table 5, the value of the ratio of the peak waveforms was approximately 0.12×10 ⁻⁶ . Therefore, the value of the peak waveform ratio in Example 3 was within the range of 0.3×10 ⁻⁶ or less. On the other hand, the particle number graph of Comparative Example 2 had a broad waveform, as shown in FIG. 12, and as shown in Table 5, the value of the ratio of the peak waveform was approximately 1.0×10 ⁻⁶ .

The present invention is useful in electrochemical devices.

10 Lithium ion capacitor 20 Positive electrode 21 Current collector 22 Electrode layer 30 Negative electrode 31 Current collector 32 Electrode layer 40 Separator 50 Fuel cell 51 Separator 52 Gas diffusion layer 53 Anode electrode catalyst layer 54 Solid polymer electrolyte membrane 55 Cathode electrode catalyst layer 100 Analyzer 200 Magnetic field generation section 201 Cell 300 Observation section 301 Enlargement section 302 Imaging section 400 Information processing section m Medium p Particles

Claims (8)

An evaluation method for evaluating characteristics of an electrochemical device, the method comprising:
The electrode member of the electrochemical device includes a carrier and an electrolytic material supported on the carrier,
The carrier includes a plurality of first particles,
Each of the plurality of first particles has a pore,
The evaluation method is
collecting the first particles from the support;
a step of causing the first particles to undergo magnetophoresis;
measuring the volume magnetic susceptibility of the first particles based on the magnetophoretic velocity of the first particles and the particle diameter of the first particles;
creating a graph showing the ratio of the number of the first particles to the volume magnetic susceptibility;
determining whether the graph includes a peak waveform;
when the peak waveform is included in the graph, evaluating the characteristics of the electrochemical device based on whether the ratio of the half width of the peak waveform to the peak value is within a specific range; ,
measuring the porosity of the first particles from the volume magnetic susceptibility of the first particles;
evaluating the characteristics of the electrochemical device based on the porosity of the first particles;
encompasses ,
The step of measuring the porosity of the first particles includes:
a step of causing second particles that are the same type of particles as the first particles and do not carry the electrolytic material to undergo magnetophoresis ;
measuring the volume magnetic susceptibility of the second particles based on the magnetophoretic velocity of the second particles and the particle diameter of the second particles;
measuring the porosity of the first particles based on the volume magnetic susceptibility of the first particles and the volume magnetic susceptibility of the second particles;
A method for evaluating electrochemical devices , including : The method for evaluating an electrochemical device according to claim 1 , wherein the electrolytic material contains lithium ions. The method for evaluating an electrochemical device according to claim 2 , wherein the carrier supports an alkali metal component. The method for evaluating an electrochemical device according to claim 1 , wherein the support supports a catalyst. The method for evaluating an electrochemical device according to claim 4 , wherein the carrier supports a surfactant. The method for evaluating an electrochemical device according to claim 4 or 5 , wherein the electrolytic material includes an ionomer. The method for evaluating an electrochemical device according to any one of claims 1 to 6 , wherein the carrier contains a carbon material. The method for evaluating an electrochemical device according to claim 7 , wherein the carrier includes activated carbon.

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