JP2019102412A - Method for producing sulfide solid electrolyte material - Google Patents

Abstract

To provide a method for producing a sulfide solid electrolyte material that can suppress ion conductivity from deteriorating.SOLUTION: The method has the step of preparing a coarse particle material as a sulfide solid electrolyte containing Li elements, P elements, S elements and X elements (X is halogen), and an atomization step for adding, to the coarse particle material, a solution in which the X elements are dissolved in a dispersion medium containing an ether compound, to atomize the coarse particle material.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method for producing a sulfide solid electrolyte material capable of suppressing a decrease in ion conductivity.

  With the rapid spread of information related devices such as personal computers, video cameras and mobile phones and communication devices in recent years, development of batteries used as the power source is regarded as important. Also, in the automobile industry and the like, development of high-power and high-capacity batteries for electric vehicles or hybrid vehicles is in progress. Among various batteries, lithium batteries are currently attracting attention from the viewpoint of high energy density.

  Since lithium batteries currently on the market use an electrolytic solution containing a flammable organic solvent, a structure for attachment of a safety device for preventing temperature rise at the time of short circuit and short circuit prevention is required. On the other hand, since the lithium battery in which the battery is totally solidified by replacing the electrolyte solution with the solid electrolyte layer does not use a flammable organic solvent in the battery, the safety device can be simplified. A sulfide solid electrolyte material is known as a solid electrolyte material used for such a solid electrolyte layer.

  For example, as a synthesis of a sulfide solid electrolyte material using ball milling, there is a wet method in which a raw material is dispersed in a polar solvent. Moreover, when producing an electrode using sulfide solid electrolyte material, it is necessary to atomize sulfide solid electrolyte material from a viewpoint of forming the contact interface of an active material and sulfide solid electrolyte material. For example, Patent Document 1 discloses a technology in which an ether compound is added as a dispersion medium to a coarse-grained material which is a sulfide solid electrolyte, and the coarse-grained material is pulverized into fine particles.

JP, 2013-020894, A

  When the sulfide solid electrolyte contains an X element (X is a halogen), there is a problem that when the ether compound is added to the sulfide solid electrolyte and atomized, the ion conductivity is lowered. This indication is made in view of the said situation, and makes it a main purpose to provide the manufacturing method of the sulfide solid electrolyte material which can control a fall of ion conductivity.

  In order to achieve the above-mentioned subject, in the present disclosure, a step of preparing a coarse-grained material which is a sulfide solid electrolyte containing Li element, P element, S element and X element (X is a halogen); A method of producing a sulfide solid electrolyte material, comprising: adding a solution in which the element X is dissolved in a dispersion medium containing an ether compound to a particle material, and atomizing the coarse particle material.

  According to the present disclosure, in the atomization step of atomizing the coarse-grained material which is a sulfide solid electrolyte, the dispersion medium added to the coarse-grained material contains an ether compound, and the X element is dissolved in the dispersion medium Thus, the decrease in the ion conductivity of the sulfide solid electrolyte material can be suppressed.

  The present disclosure has the effect of being able to provide a method for producing a sulfide solid electrolyte material capable of suppressing a decrease in ion conductivity.

It is a flowchart which shows an example of the manufacturing method of the sulfide solid electrolyte material of this indication. It is a flowchart which shows the manufacturing method of the sulfide solid electrolyte material in an Example. It is the result of the XRD measurement with respect to the sulfide solid electrolyte material in an Example and Comparative Examples 1 and 2.

  Hereinafter, the method for producing the sulfide solid electrolyte material of the present disclosure will be described in detail.

  The method of producing a sulfide solid electrolyte material according to the present disclosure comprises the steps of preparing a coarse particle material which is a sulfide solid electrolyte containing Li element, P element, S element and X element (X is a halogen); The particulate material is added with a solution in which the element X is dissolved in a dispersion medium containing an ether compound, and an atomizing step of atomizing the coarse particle material.

  FIG. 1 is a flow chart showing an example of a method for producing a sulfide solid electrolyte material of the present disclosure. As shown in FIG. 1, in the method for producing a sulfide solid electrolyte material according to the present disclosure, first, a coarse-grained material which is a sulfide solid electrolyte containing Li element, P element, S element and X element (X is a halogen) Prepare (preparation process). Next, a dispersion medium is added to the prepared coarse-grained material, and the coarse-grained material is micronized (atomization step). In the present disclosure, the dispersion medium contains an ether compound, and the X element is dissolved in the dispersion medium. This makes it possible to obtain a finely divided sulfide solid electrolyte material.

According to the present disclosure, in the atomization step of atomizing the coarse-grained material which is a sulfide solid electrolyte, the dispersion medium added to the coarse-grained material contains an ether compound, and the X element is dissolved in the dispersion medium Thus, the decrease in the ion conductivity of the sulfide solid electrolyte material can be suppressed.
As described above, when the sulfide solid electrolyte contains the element X (X is a halogen), when the ether compound is added to the coarse-grained material which is the sulfide solid electrolyte and the coarse-grained material is finely divided, ion conduction is caused. There is a problem that the degree falls. The reason is presumed to be as follows. That is, the coarse material is sulfide solid electrolyte containing X element, the addition of ether compound as the dispersion medium, X from coarse material in the atomization step ^- ions will be eluted ether compound. Then, the element X is lost from the sulfide solid electrolyte in the atomization step, and it is estimated that the ion conductivity of the sulfide solid electrolyte material is lowered by shifting from the composition at the time of preparation. Specifically, it is estimated that the ion conductivity of the sulfide solid electrolyte material is reduced by an amount corresponding to the amount of loss of the element X from the sulfide solid electrolyte.

On the other hand, the inventors of the present disclosure have found that the dispersion medium added to the coarse-grained material, which is a sulfide solid electrolyte in the atomization step, contains an ether compound, and the X element is dissolved in the dispersion medium. It has been found that the elution of X ^- ions from coarse-grained materials to ether compounds can be suppressed. The reason is presumed to be as follows. That is, when a sulfide solid electrolyte containing an X element (X is a halogen) is dispersed in an ether compound, the dissolution equilibrium of LiX⇔Li ⁺ + X ⁻ is inclined to the right, and Li ⁺ ion and X from the sulfide solid electrolyte ^-The ions are eluted into the ether compound. On the other hand, if the element X is dissolved in advance in the dispersion medium, when the sulfide solid electrolyte is dispersed in the dispersion medium, the dissolution equilibrium of LiX⇔Li ⁺ + X ⁻ becomes difficult to tilt to the right, resulting in the sulfide solid It is speculated that the elution of X ^- ions from the electrolyte to the ether compound can be suppressed.

  Hereinafter, the method for producing the sulfide solid electrolyte material of the present disclosure will be described step by step.

1. Preparation Step The preparation step is a step of preparing a coarse-grained material which is a sulfide solid electrolyte containing Li element, P element, S element and X element (X is a halogen).

The coarse-grained material contains a Li element, a P element, an S element and an X element (X is a halogen). Examples of the X element include Cl element, Br element and I element. The X element may be of one type, or of two or more types. Furthermore, the coarse-grained material may contain at least one of Ge element, Si element and Sn element. In addition, the coarse-grained material may contain an O element. The coarse-grained material preferably has PS ₄ ^3- as an anion structure. The coarse-grained material may have, in addition to PS ₄ ^3- , at least one of GeS ₄ ^4- , SiS ₄ ^4- and SnS ₄ ^4- as an anion structure.

The coarse-grained material may contain an ion conductor containing Li, P and S elements. The ion conductor preferably contains PS ₄ ^3- as a main component of the anion structure. The phrase "having PS ₄ ^3- as the main component of the anion structure" means that the proportion of PS ₄ ^3- is the largest among all the anion structures in the ion conductor. The proportion of PS ₄ ^3- in the total anion structure is, for example, 60 mol% or more, and may be 70 mol% or more, 80 mol% or more, or 90 mol% or more. The proportion of PS ₄ ^3- can be determined by, for example, Raman spectroscopy, NMR, or XPS. In addition, a part of the S element of the ion conductor may be replaced by the O element.

  When the coarse-grained material contains the above ion conductor, it usually further contains LiX. Examples of LiX include LiCl, LiBr and LiI. In addition, at least a part of LiX is preferably present in the form of being incorporated into the structure of the ion conductor as LiX. The proportion of LiX in the coarse-grained material is, for example, 1 mol% or more, and may be 10 mol% or more. On the other hand, the ratio of LiX is, for example, 50 mol% or less, and may be 35 mol% or less.

  The coarse-grained material may be amorphous or crystalline. An example of the former is a sulfide glass, and an example of the latter is a crystallized sulfide glass (glass ceramic).

Examples of the shape of the coarse-grained material include particulates. The average particle size (D ₅₀ ) of the coarse-grained material is, for example, 5 μm or more, and may be 10 μm or more. On the other hand, the mean particle size (D ₅₀ ) of the coarse-grained material is, for example, 200 μm or less, and may be 100 μm or less. In addition, the average particle diameter of coarse particle material can be determined by a particle size distribution analyzer, for example. The coarse-grained material preferably has high ion conductivity, and the ion conductivity at normal temperature is, for example, 1 × 10 ⁻⁴ S / cm or more, and may be 1 × 10 ⁻³ S / cm or more. .

2. Atomization Step The atomization step is a step of adding a solution in which the element X is dissolved in a dispersion medium containing an ether compound to the coarse particle material, to atomize the coarse particle material. That is, in the atomization step, the element X is dissolved in the dispersion medium, and a solution in which the element X is dissolved is added to the coarse particle material.

  In the solution used in the atomization step, the X element (X is a halogen) is dissolved. The element X can be the same as the element X described in the section “1. Preparation process” described above, and thus the description thereof is omitted here. Further, the element X dissolved in the solution is usually the same element as the element X contained in the coarse-grained material. When the coarse-grained material contains two or more types of X elements, at least one of the X elements and the X element to be dissolved in the solution may be the same. When LiX is dissolved in the dispersion medium, the concentration of LiX dissolved in the dispersion medium may be any concentration that can achieve the effects of the present disclosure, and in particular, the saturation concentration is preferable. The concentration of LiX dissolved in the dispersion medium is, for example, 1.5 mol / L or more, preferably 3.0 mol / L or more, and more preferably 5.0 mol / L or more.

  The dispersion medium contains an ether compound. By containing the ether compound, adhesion and granulation of the coarse-grained material to the media can be suppressed. As a result, the atomized sulfide solid electrolyte material can be obtained at a high recovery rate. The recovery rate of the sulfide solid electrolyte material is, for example, 90% or more, and preferably 95% or more. The recovery rate can be calculated by (recovery amount of the finely divided sulfide solid electrolyte material) / (addition amount of coarse particle material).

  The ether compound contained in the dispersion medium functions as a dispersion medium for dispersing the coarse-grained material. Thus, ether compounds are polar aprotic solvents. The ether compound contained in the dispersion medium may be only one type or a mixture of two or more types.

  Here, the ether compound is a compound having an ether group (C-O-C). The ether compound is preferably, for example, a compound having two hydrocarbon groups bonded to an oxygen element. It is because the reactivity with coarse-grained material is low. The carbon number of the hydrocarbon group is preferably 10 or less. If the carbon number is too large, removal of the ether compound by drying may be difficult.

  The hydrocarbon group may be linear or cyclic. The hydrocarbon group is preferably a saturated hydrocarbon group or an aromatic hydrocarbon group. As such a hydrocarbon group, for example, alkyl group such as methyl group, ethyl group, propyl group, isopropyl group and butyl group, cycloalkyl group such as cyclopentyl group and cyclohexyl group, and aromatic carbonization such as phenyl group and benzyl group A hydrogen group etc. can be mentioned. Specific examples of the ether compound include dimethyl ether, methyl ethyl ether, dipropyl ether, dibutyl ether, cyclopentyl methyl ether, anisole and the like. The molecular weight of the ether compound is, for example, 46 or more, and may be 74 or more. On the other hand, the molecular weight of the ether compound is, for example, 278 or less and may be 186 or less.

  The dispersion medium may contain a solvent other than the ether compound. When the dispersion medium contains a solvent other than an ether compound, that is, when the dispersion medium is a mixed solvent, the mixing ratio of the ether compound in the dispersion medium to the solvent other than that is appropriately determined according to the type of coarse particle material. It can be adjusted. Above all, it is preferable to adjust the mixing ratio so that the dispersion medium satisfies the HSP value described later. The specific mixing ratio of the ether compound to the other solvent in the dispersion medium is, for example, 95: 5 to 5:95 (volume ratio).

  Examples of solvents other than ether compounds include hydrocarbon solvents. The hydrocarbon-based solvent is a solvent comprising carbon atoms and hydrogen atoms. Examples of hydrocarbon solvents include saturated hydrocarbons, unsaturated hydrocarbons, aromatic hydrocarbons and the like. Examples of saturated hydrocarbon solvents include hexane, pentane, 2-ethylhexane, heptane, octane, decane, cyclohexane, methylcyclohexane and the like. Examples of unsaturated hydrocarbons include hexene, heptene, cyclohexene and the like. Examples of the aromatic hydrocarbon include toluene, xylene, ethylbenzene, decalin, 1,2,3,4-tetrahydronaphthalene and the like. The hydrocarbon-based solvent contained in the dispersion medium may be only one type, or may be a mixture of two or more types.

  The dispersion medium is preferably a solvent having high dispersibility of the coarse-grained material. In the present disclosure, attention is focused on a Hansen solubility parameter (hereinafter referred to as “HSP”) which is a parameter. The term "HSP" as used herein means a parameter of vector quantity obtained by dividing Hildebrand's solubility parameter into three cohesive energy components of London dispersion force, interpolar force and hydrogen bonding force. The component corresponding to the London dispersion force of HSP is described as the dispersion term "δd", the component corresponding to the interpolar force is described as the polar term "δp", and the component corresponding to the hydrogen bonding force is the hydrogen bond term "δh Write ". Since HSP is a vector quantity, it is known that almost no pure substance having exactly the same value exists. In addition, HSPs of commonly used substances have databases constructed. Therefore, those skilled in the art can obtain the HSP value of the desired substance by referring to the database. Those skilled in the art can calculate HSP values from their chemical structures by using computer software such as Hansen Solubility Parameters in Practice (HSPiP), even for substances for which HSP values have not been registered in the database. . In the case of a mixture comprising a plurality of substances, the HSP value of the mixture can be calculated as the sum of the HSP value of each substance which is the component and the volume ratio of the component to the entire mixture. For HSP, reference can be made to, for example, Hiroshi Yamamoto, S. Abbott, C. M. Hansen, Chemical Industry, March 2010 issue. The HSP value of the dispersion medium is, for example, HSP value: (δd, δp, δh) = (16.0 ± 2.0, 3.6 ± 2.0, 4.9 ± 2.0), and the HSP value: (Δd, δp, δh) = (16.0 ± 1.0, 3.6 ± 1.0, 4.9 ± 1.0), HSP value: (δd, δp, δh) = (16.0 ± 0.8, 3.6 ± 0.7, 4.9 ± 0.6).

  The addition amount of the above-mentioned solution (dispersion medium in which LiX is dissolved) to be added to the coarse-grained material is not particularly limited as long as it is a ratio at which the finely divided sulfide solid electrolyte material can be obtained. The amount of the ether compound added is, for example, 0.01% by weight or more, preferably 0.1% by weight, and preferably 1% by weight or more, based on the coarse-grained material. On the other hand, the addition amount of the ether compound is, for example, 100% by weight or less and preferably 50% by weight or less based on the coarse-grained material. If the amount of the ether compound added is too small, it may be difficult to prevent granulation of the coarse-grained material during grinding and adhesion of the coarse-grained material to the medium. On the other hand, if the addition amount of the ether compound is too large, removal of the ether compound may be difficult.

  The atomization step is not particularly limited as long as the method can atomize the coarse-grained material. Examples of the method of atomizing the coarse-grained material include media type grinding such as bead mill and planetary ball mill, jet grinding, cavitation grinding and the like. The grinding conditions can be appropriately set according to the type of coarse-grained material and the particle size of the target coarse-grained material.

  In the atomization step, drying is usually performed to remove the solution (dispersion medium in which LiX is dissolved). The drying temperature is not particularly limited, but in particular in the case where the ion conductivity decreases due to crystallization of the sulfide glass, the drying temperature needs to be noted.

3. Other Steps In the present disclosure, the atomization step may be followed by a heat treatment step of heat-treating the atomized sulfide solid electrolyte material. By heat treatment, for example, crystallized crystallized sulfide glass (glass ceramic) can be obtained. In particular, when the ion conductivity is improved by the crystallization of the sulfide glass, it is preferable to perform a heat treatment step. The heat treatment temperature in the heat treatment step is preferably a temperature equal to or higher than the crystallization temperature, and is preferably adjusted so that a crystal phase having high ion conductivity is generated (an unnecessary crystal phase is not generated). The same applies to the heat treatment time in the heat treatment step.

  The sulfide solid electrolyte material after the heat treatment step preferably mainly generates an LGPS type crystal phase. On the other hand, in the above-mentioned sulfide solid electrolyte material, it is preferable that the aldehyde-type crystal phase is not generated as the impurity phase.

4. Atomized sulfide solid electrolyte material The average particle diameter (D ₅₀ ) of the sulfide solid electrolyte material atomized by the atomizing step may be smaller than that of the coarse particle material, for example, 0.1 μm or more, 0.5 μm It may be more than. On the other hand, the average particle diameter (D ₅₀ ) of the sulfide solid electrolyte material is, for example, 5 μm or less, and may be 4 μm or less. The average particle size (D ₅₀ ) of the sulfide solid electrolyte material can be determined, for example, by a particle size distribution analyzer.

  The sulfide solid electrolyte material obtained by the production method of the present disclosure can suppress the decrease in ion conductivity due to the atomization step. Specifically, the ion conductivity (25 ° C.) of the sulfide solid electrolyte material after the atomization step with respect to the ion conductivity (25 ° C.) of the coarse-grained material is, for example, 50% or more and 70% or more Is more preferable, 80% or more is further preferable, and 90% or more is particularly preferable. The ion conductivity of the sulfide solid electrolyte material can be determined, for example, by an alternating current impedance method.

  The sulfide solid electrolyte material is 2θ = 20.18 ° ± 1.00 °, 20.44 ° ± 1.00 °, 26.96 ° ± 1.00 ° in X-ray diffraction measurement using a CuKα ray. It is preferable to provide a crystalline phase having a peak at 29.58 ° ± 1.00 °. These peak positions may be shifted within ± 0.50 °. Moreover, this crystal phase is a crystal phase having high Li ion conductivity, and is known as a so-called LGPS type crystal phase. This crystalline phase may be referred to as crystalline phase A. In addition to the above, the crystal phase A is usually 2θ = 17.38 °, 23.56 °, 23.96 °, 24.93 °, 29.07 °, 31.71 °, 32.66 °, 33. It has a peak at .39 °. These peak positions may also be shifted within ± 1.00 °, or may be shifted within ± 0.50 °.

  The sulfide solid electrolyte material preferably does not have a crystal phase having a peak at 2θ = 27.33 ° ± 0.50 ° in X-ray diffraction measurement using a CuKα ray. This crystal phase is a crystal phase having lower Li ion conductivity than the LGPS type crystal phase. This crystal phase may be referred to as crystal phase B. In addition to 2θ = 27.33 °, crystal phase B is usually 2θ = 17.46 °, 18.12 °, 19.99 °, 22.73 °, 25.72 °, 27.33 °. , At 29.16 ° and 29.78 °. These peak positions may also be shifted within ± 1.00 °, or may be shifted within ± 0.50 °.

Assuming that the peak intensity around 2θ = 29.58 ° of the crystal phase A is I _A and the peak intensity around 2θ = 27.33 ° of the crystal phase B is I _B , the value of I _B / I _A is, for example, Less than 0.50, preferably less than or equal to 0.45, and more preferably less than or equal to 0.15. In particular, the value of I _B / I _A is preferably 0.

  The sulfide solid electrolyte material obtained by the production method of the present disclosure can be used in any application that requires ion conductivity. Among them, the sulfide solid electrolyte material is preferably used for an all solid battery (particularly, an all solid secondary battery). Furthermore, when using a sulfide solid electrolyte material for an all solid battery, it may be used for a positive electrode active material layer, may be used for a negative electrode active material layer, and may be used for a solid electrolyte layer.

  The present disclosure can also provide a sulfide solid electrolyte material characterized by being obtained by the above-described production method. Furthermore, the above-mentioned sulfide solid electrolyte material may be contained in at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer, to provide an all solid battery.

  The present disclosure is not limited to the above embodiment. The above-described embodiment is an exemplification, which has substantially the same configuration as the technical idea described in the claims of the present disclosure, and exhibits the same operation and effect as the present invention. It is included in the technical scope of the disclosure.

Hereinafter, the present disclosure will be described more specifically by showing examples.
In addition, when handling a raw material, a mixture, and a sulfide solid electrolyte, the operation was performed in a glove box adjusted to a dew point of −70 ° C. or less under an Ar gas atmosphere.

[Example]
A finely divided sulfide solid electrolyte material was synthesized according to the flow chart shown in FIG. The detailed procedure will be described below based on the flowchart shown in FIG.

<Synthesis of coarse-grained material>
As starting materials, Li ₂ S (manufactured by Mitsutsuwa Chemical Industry Co., Ltd.), P ₂ S ₅ (manufactured by Aldrich), SiS ₂ (manufactured by Mitsutsuka Chemical Industry), LiCl (manufactured by Mitsutsuka Chemical Industry Co., Ltd.) were used. Next, each raw material was weighed and mixed so as to be 2 g in a composition ratio of Li _3.18 Si _0.58 P _0.48 S _3.9 Cl _0.1 . The mixture was placed in a zirconia ball pot container (volume 45 ml) together with a zirconia ball (? 5 mm, 53 g), and the container was sealed. The container was attached to a planetary ball mill (PULVERISETTE 7 manufactured by Fritsch), and mechanical milling was performed for 40 hours at a table rotation speed of 500 rpm. Thereby, a glass precursor (coarse-grained material) of a sulfide solid electrolyte was obtained.

Atomization process
The obtained coarse-grained material is put in a zirconia ball pot container (volume 45 ml) together with a heptane-dibutyl ether mixed solution in which zirconia balls (φ 0.3 mm, 53 g), heptane 4 g, dibutyl ether 2 g, and LiCl are dissolved. , The container was sealed. A heptane-dibutyl ether mixed solution in which LiCl is dissolved is mechanically milled with a zirconia ball (φ 0.3 mm, 53 g), heptane 4 g, dibutyl ether 2 g, LiCl 2 g at a rotational speed of 300 rpm for 20 hours. It was prepared by placing the supernatant and fractionating it. Therefore, the obtained solution is a LiCl saturated solution. This container was attached to a planetary ball mill and subjected to mechanical milling at a table rotation speed of 300 rpm for 20 hours to atomize a glass precursor (coarse-grained material) of a sulfide solid electrolyte. Thereby, the finely divided coarse-grained material was then thoroughly washed with heptane and dried in an environment of 100 ° C.

<Heat treatment process>
The atomized coarse-grained material was vacuum sealed in a quartz tube and heat-treated at 475 ° C. for 3 hours. Thus, a crystalline sulfide solid electrolyte material was synthesized.

Comparative Example 1
A sulfide solid electrolyte material was synthesized in the same manner as in Example except that the dispersion medium used in the atomization step did not contain the element X (LiCl).

Comparative Example 2
A sulfide solid electrolyte material was synthesized in the same manner as in the example except that the atomization step was not performed.

[Evaluation]
(XRD measurement)
The X-ray diffraction measurement (XRD measurement) was performed on the sulfide solid electrolyte material obtained in the example and the comparative examples 1 and 2. For measurement, a powder X-ray diffractometer (Uttma IV, manufactured by Rigaku) was used, and a CuKα ray (range of 2θ = 10 ° to 60 °) was used as a radiation source. The results are shown in FIGS. 3 (a) and 3 (b). 3 (b) is an enlarged view of FIG. 3 (a).

  As shown in FIG. 3, in the example, it is confirmed that the LGPS type crystal phase is precipitated, and in the comparative example 1, it is confirmed that the algirodite type crystal phase is precipitated in addition to the LGPS type crystal phase. In Comparative Example 2, it was confirmed that the LGPS type crystal phase was precipitated.

(Li ion conductivity measurement)
100 mg of the sulfide solid electrolyte material obtained in Example and Comparative Examples 1 and 2 was weighed, placed in a cylinder (manufactured by Macor), and pressed (6 ton). Next, the evaluation cell was constructed by pinching both ends of the pellet with a SUS pin and restraining at 6.0 N / m with a bolt. The alternating current impedance measurement was performed in the state which kept the obtained evaluation cell at 25 degreeC. Thus, the Li ion conductivity of the sulfide solid electrolyte material was calculated. For measurement, VMP3 manufactured by Biologic was used, and the applied voltage was 10 mV and the measurement frequency range was 0.01 MHz to 1 MHz. The results are shown in Table 1.

(Particle size distribution measurement)
A small amount of the sulfide solid electrolyte material obtained in the example and the comparative examples 1 and 2 and the coarse-grained material obtained in the step of preparing the coarse-grained material are sampled, and a laser scattering / diffraction type particle size distribution analyzer (Nikkiso Micro Co., Ltd.) The particle size distribution was measured on a track MT 3300 EXII) to determine the average particle size (D ₅₀ ). The results are shown in Table 1.

Comparative Example 2 is an example in which the atomization step was not performed. As shown in Table 1, the ion conductivity of the sulfide solid electrolyte material when the atomization step was not performed was 9.4 mS cm ⁻¹ . On the other hand, the example is an example in which the atomization step is performed, the dispersion medium used at this time contains an ether compound, and the X element is dissolved in the dispersion medium. Further, Comparative Example 1 is an example in which the atomization step is performed, the dispersion medium used at this time contains an ether compound, and the X element is not dissolved in the dispersion medium. As a result of comparing the ion conductivity of Comparative Example 2 with Example and Comparative Example 1, in the Example, although the decrease in ion conductivity due to the atomization process could be suppressed to about 1/3, in Comparative Example 1 The decrease in ion conductivity due to the atomization step was about 1/6, and the decrease in ion conductivity was significant as compared with the examples. From the above, the dispersion medium used in the atomization step contains an ether compound, and the element X is dissolved in the dispersion medium, so that the decrease in ion conductivity due to the atomization step can be suppressed. I understood.

  As shown in FIG. 3, in Comparative Example 2, the LGPS type crystal phase was precipitated as a single phase. On the other hand, in Comparative Example 1, in addition to the LGPS type crystal phase, an algirodite type crystal phase was precipitated as an impurity phase. Moreover, when the XRD measurement result of the comparative examples 1 and 2 was compared, in the comparative example 1, it has confirmed that the peak of the LGPS type | mold crystal phase shifted to the high angle side, and the composition shift has arisen. On the other hand, in the example, the LGPS type crystal phase was precipitated as a single phase, and the compositional deviation could also be suppressed.

Claims (1)

Preparing a coarse-grained material which is a sulfide solid electrolyte containing Li element, P element, S element and X element (X is a halogen);
A method of manufacturing a sulfide solid electrolyte material, comprising: adding a solution in which the X element is dissolved in a dispersion medium containing an ether compound to the coarse-grained material, and atomizing the coarse-grained material into fine particles.

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