Method for producing halide

Abstract

The production method according to the present disclosure comprises a firing step for firing a mixed material comprising a compound containing Y, a compound containing Gd, NH4α, Liβ and Caγ2 under an inert gas atmosphere, in which the compound containing Y comprises at least one compound selected from the group consisting of Y2O3 and Yδ3, the compound containing Gd comprises at least one compound selected from the group consisting of Gd2O3 and Gdε3, the mixed material contains at least one compound selected from the group consisting of Y2O3 and Gd2O3, and α, β, γ, δ and ε independently represent at least one atom selected from the group consisting of F, Cl, Br and I.

Description

Technical Field

[0001] The present disclosure relates to a method for producing a halide.

Background Art

[0002] Patent Document 1 discloses a method for producing a halide solid electrolyte.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a method for producing a halide with high industrial productivity.

Means for Solving the Problems

[0005] The production method of the present disclosure includes a firing step of firing a mixed material containing a compound containing Y, a compound containing Gd, NH4α, Liβ, and Caγ2 in an inert gas atmosphere. Here, the compound containing Y is at least one selected from the group consisting of Y2O3 and Yδ3, the compound containing Gd is at least one selected from the group consisting of Gd2O3 and Gdε3, the mixed material includes at least one selected from the group consisting of Y2O3 and Gd2O3, and α, β, γ, δ, and ε are each independently at least one selected from the group consisting of F, Cl, Br, and I.

Effects of the Invention

[0006] The present disclosure provides a method for producing a halide with high industrial productivity.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings.

[0009] (First Embodiment) Figure 1 is a flowchart showing an example of a manufacturing method according to the first embodiment.

[0010] The manufacturing method according to the first embodiment includes a firing step S1000. In the firing step S1000, the mixed material is fired in an inert gas atmosphere.

[0011] The mixed material fired in the firing process S1000 is a material in which a compound containing Y, a compound containing Gd, NH4α, Liβ, and Caγ2 are mixed. Here, the compound containing Y is at least one selected from the group consisting of Y2O3 and Yδ3. The compound containing Gd is at least one selected from the group consisting of Gd2O3 and Gdε3. The mixed material contains at least one selected from the group consisting of Y2O3 and Gd2O3. α, β, γ, δ, and ε are each independently at least one selected from the group consisting of F, Cl, Br, and I. Hereinafter, the above-mentioned "compound containing Y" and "compound containing Gd" are referred to as "Y-containing compound" and "Gd-containing compound", respectively.

[0012] The manufacturing method according to the first embodiment is an industrially highly productive method for manufacturing a halide. An industrially highly productive method is, for example, a method that can be produced in large quantities at low cost. That is, by a simple manufacturing method (that is, firing in an inert gas atmosphere), a halide containing Li (that is, lithium), Y (that is, yttrium), Gd (that is, gadolinium), and Ca (that is, calcium) can be produced.

[0013] The manufacturing method according to the first embodiment does not have to use a vacuum sealed tube and a planetary ball mill.

[0014] The mixed material may contain Y2O3, Gd2O3, NH4α, Liβ, and Caγ2. Since Y2O3, Gd2O3, and NH4α contained in the mixed material are inexpensive, the manufacturing cost can be reduced.

[0015] In order to further increase the ionic conductivity of the halide, α, β, γ, δ, and ε may each independently be at least one selected from the group consisting of Cl and Br.

[0016] For example, from Y2O3, Gd2O3, NH4α, Liα (i.e., the one where β in the above-mentioned Liβ is α), and Caα2 (i.e., the one where γ in the above-mentioned Caγ2 is α), Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 When producing α6, as a whole system, the reaction represented by the following formula (1) is considered to proceed.

[0017] 0.5Y2O3 + 0.5Gd2O3 + 12NH4α + 6Liα + 0.2Caα2 → 2Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 α6 + 12NH3 + 6Hα + 3H2O ···(1)

[0018] In the firing step S1000, for example, the powder of the mixed material may be placed in a container (e.g., a crucible) and fired in a heating furnace. At this time, the state where the mixed material is heated to a predetermined temperature in an inert gas atmosphere may be maintained for a predetermined time or longer. The firing time may be a length of time that does not cause a compositional shift of the fired product due to, for example, the volatilization of the halide. The firing time that does not cause a compositional shift of the fired product means the firing time that does not impair the ionic conductivity of the fired product. According to the manufacturing method according to the first embodiment, for example, a halide having an ionic conductivity of 3.0×10 -9 S / cm or more can be produced near room temperature.

[0019] The inert gas atmosphere means, for example, an atmosphere in which the total concentration of gases other than the inert gas is 1% by volume or less. Examples of the inert gas are helium, nitrogen, or argon.

[0020] After the firing step S1000, the fired product may be pulverized. At this time, a pulverizing tool (e.g., a mortar or a mixer) may be used.

[0021] At least one selected from the group consisting of the Y-containing compound, Gd-containing compound, Liβ, and Caγ2 contained in the mixed material may have a part of the metal cation substituted by another metal cation. That is, a part of Y, Gd, Li, and Ca may be substituted by another metal cation. That is, the mixed material may further contain a compound in which a part of Y is substituted by another metal cation in the Y-containing compound, a compound in which a part of Gd is substituted by another metal cation in the Gd-containing compound, a compound in which a part of Li is substituted by another metal cation in Liβ, or a compound in which a part of Ca is substituted by another metal cation in Caγ2. Thereby, the properties (for example, ionic conductivity) of the produced halide can be improved. The cation substitution rate by another metal cation for Y, Gd, Li, and Ca may be less than 50 mol%. Thereby, a halide having a more stable structure can be obtained.

[0022] At least one selected from the group consisting of the Y-containing compound, Gd-containing compound, Liβ, and Caγ2 contained in the mixed material may have a part of the metal cation substituted by at least one cation selected from the group consisting of, for example, Na, K, Mg, Sr, Ba, Zn, In, Sn, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0023] The mixed material may be a material in which a Y-containing compound, a Gd-containing compound, NH4α, Liβ, and Caγ2 are mixed.

[0024] Alternatively, the mixed material may be a material in which, in addition to the Y-containing compound, Gd-containing compound, NH4α, Liβ, and Caγ2, other materials different from Y2O3, Yδ3, Gd2O3, Gdε3, NH4α, Liβ, and Caγ2 are further mixed.

[0025] In the firing process S1000, the mixed material may be fired at 350°C or higher. Thereby, a halide having high ionic conductivity can be produced by an industrially highly productive method. By setting the firing temperature to 350°C or higher, the mixed material can react sufficiently. That is, the Y-containing compound, Gd-containing compound, NH4α, Liβ, and Caγ2 can react sufficiently. When the mixed material is fired at 350°C or higher, for example, a halide having an ionic conductivity of 1.0×10 -4 S / cm or more can be produced at around room temperature. Here, the firing temperature is the ambient temperature.

[0026] In order to produce a halide having higher ionic conductivity by an industrially highly productive method, the mixed material may be fired at 700°C or lower. The mixed material may be fired, for example, at 350°C or higher and 700°C or lower. By setting the firing temperature to 700°C or lower, thermal decomposition of the halide produced by the solid-phase reaction can be suppressed. As a result, the ionic conductivity of the fired halide can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0027] In order to produce a halide having higher ionic conductivity by an industrially highly productive method, the mixed material may be fired at 650°C or lower. The mixed material may be fired, for example, at 350°C or higher and 650°C or lower. Thereby, thermal decomposition of the halide produced by the solid-phase reaction can be suppressed. As a result, the ionic conductivity of the fired halide can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0028] In the above formula (1), after reacting Y2O3, Gd2O3, and NH4α with each other, Y2O3 and Gd2O3 may be halogenated. Next, a firing profile may be set such that the halogenated Y2O3 and Gd2O3 react with Liβ and Caγ2. In this case, the firing temperature may be a temperature lower than the sublimation point or the melting point of NH4α, and may also be a temperature at which the halogenated Y2O3 and Gd2O3 react with Liβ and Caγ2. That is, the firing temperature may be a temperature lower than the sublimation point or the melting point of NH4α, and may also be a temperature at which a halide solid electrolyte material is formed.

[0029] For example, from Y2O3, Gd2O3, NH4Cl, LiCl, and CaCl2, Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 When synthesizing Cl6, it is considered that the reaction represented by the following formula (2) proceeds.

[0030] 0.5Y2O3 + 0.5Gd2O3 + 12NH4Cl + 5.6LiCl + 0.2CaCl2 → 2Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 Cl6 + 12NH3 + 6HCl + 3H2O ···(2)

[0031] The firing temperature in this reaction may be set to about 300°C. That is, the firing temperature may be a temperature lower than about 335°C, which is the sublimation point of NH4Cl, and may also be set to a temperature at which a halide solid electrolyte material is formed. In order to produce a halide having a higher ionic conductivity, the firing temperature may be 350°C or higher. In such a case, as shown in the second embodiment described later, the firing process may be made into two or more stages. At this time, the firing temperature of the first firing process may be a temperature lower than the sublimation point of NH4α, and the firing temperature of the firing process after the second stage and later may be set to a higher temperature.

[0032] The mixed material may be fired for 1 hour or more and 72 hours or less. Thereby, a halide having higher ionic conductivity can be produced by an industrially highly productive method. By setting the firing time to 1 hour or more, the mixed material can react sufficiently. That is, the Y-containing compound, the Gd-containing compound, NH4α, Liβ, and Caγ2 can react sufficiently. By setting the firing time to 72 hours or less, volatilization of the fired halide can be suppressed. That is, a halide having the target composition ratio can be obtained. As a result, a decrease in the ionic conductivity of the halide due to compositional deviation can be suppressed. That is, a higher-quality halide solid electrolyte material can be obtained.

[0033] FIG. 2 is a flowchart showing an example of the manufacturing method according to the first embodiment.

[0034] As shown in FIG. 2, the manufacturing method according to the first embodiment may further include a mixing step S1100.

[0035] The mixing step S1100 is executed before the firing step S1000.

[0036] In the mixing step S1100, the Y-containing compound, the Gd-containing compound, NH4α, Liβ, and Caγ2 are mixed. Thereby, a mixed material is obtained. That is, the material to be fired in the firing step S1000 is obtained.

[0037] For mixing the raw materials, known mixing appliances (for example, a mortar, a blender, or a ball mill) may be used.

[0038] For example, in the mixing step S1100, powders of the respective raw materials may be prepared and mixed. At this time, in the firing step S1000, the powdery mixed material may be fired. The powdery mixed material obtained in the mixing step S1100 may be formed into a pellet shape by pressing. Alternatively, in the firing step S1000, the pellet-shaped mixed material may be fired.

[0039] In the mixing step S1100, a mixed material may be obtained by further mixing not only a Y-containing compound, a Gd-containing compound, NH4α, Liβ, and Caγ2, but also other materials different from Y2O3, Yδ3, Gd2O3, Gdε3, NH4α, Liβ, and Caγ2.

[0040] In the mixing step S1100, a raw material mainly composed of a Y-containing compound, a raw material mainly composed of a Gd-containing compound, a raw material mainly composed of NH4α, a raw material mainly composed of Liβ, and a raw material mainly composed of Caγ2 may be mixed. The main component means the component contained in the largest amount in terms of molar ratio.

[0041] In the mixing step S1100, the Y-containing compound, the Gd-containing compound, NH4α, Liβ, and Caγ2 may be prepared and mixed so as to have a target composition.

[0042] When Y2O3 and Gd2O3 are used as the Y-containing compound and the Gd-containing compound, respectively, Y2O3, Gd2O3, NH4Cl, LiCl, and CaCl2 may be mixed, for example, at a molar ratio of Y2O3:Gd2O3:NH4Cl:LiCl:CaCl2 = 0.25:0.25:6:2.8:0.1. Thereby, Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 A halide having a composition represented by Cl6 can be produced.

[0043] The molar ratios of the Y-containing compound, the Gd-containing compound, NH4α, Liβ, and Caγ2 may be adjusted in advance so as to offset the compositional changes that may occur in the firing step S1000.

[0044] In order to allow the synthesis reaction in the firing step S1000 to proceed smoothly, NH4α may be prepared in an amount in excess of Y2O3 and Gd2O3. For example, NH4α is prepared in an amount 5 to 15 mol% in excess of the total of Y2O3 and Gd2O3.

[0045] In the mixing step S1100, at least one selected from the group consisting of a Y-containing compound, a Gd-containing compound, Liβ, and Caγ2 may have a part of the metal cations substituted by another metal cation. That is, a part of Y, Gd, Li, and Ca may be substituted by another metal cation. That is, a compound in which a part of Y in the Y-containing compound is substituted by another metal cation, a compound in which a part of Gd in the Gd-containing compound is substituted by another metal cation, a compound in which a part of Li in Liβ is substituted by another metal cation, or a compound in which a part of Ca in Caγ2 is substituted by another metal cation may be further mixed to obtain a mixed material. The cation substitution rate by another metal cation for Y, Gd, Li, and Ca may be less than 50 mol%.

[0046] FIG. 3 is a flowchart showing an example of the manufacturing method according to the first embodiment.

[0047] As shown in FIG. 3, the manufacturing method according to the first embodiment may further include a preparation step S1200.

[0048] The preparation step S1200 is executed before the mixing step S1100.

[0049] In the preparation step S1200, raw materials such as a Y-containing compound, a Gd-containing compound, NH4α, Liβ, and Caγ2 are prepared. That is, the materials to be mixed in the mixing step S1100 are prepared.

[0050] In the preparation step S1200, a Y-containing compound, a Gd-containing compound, NH4α, Liβ, and Caγ2 and the like may be synthesized. Alternatively, in the preparation step S1200, (for example, materials with a purity of 99% or more) may be used.

[0051] The prepared materials may be dried.

[0052] Examples of the shape of the material to be prepared are crystalline, massive, flaky, or powdery. In the preparation step S1200, a powdery raw material may be obtained by pulverizing a crystalline, massive, or flaky raw material.

[0053] In the preparation step S1200, at least one selected from the group consisting of a Y-containing compound, a Gd-containing compound, Liβ, and Caγ2 may have a part of the metal cations substituted by another metal cation. That is, a part of Y, Gd, Li, and Ca may be substituted by another metal cation. That is, a compound in which a part of Y in the Y-containing compound is substituted by another metal cation, a compound in which a part of Gd in the Gd-containing compound is substituted by another metal cation, a compound in which a part of Li in Liβ is substituted by another metal cation, or a compound in which a part of Ca in Caγ2 is substituted by another metal cation may be further prepared. The cation substitution rate by another metal cation of Y, Gd, Li, and Ca may be less than 50 mol%.

[0054] The halide produced by the production method according to the first embodiment can be used as a solid electrolyte material. The solid electrolyte material is, for example, a solid electrolyte material having lithium ion conductivity. The solid electrolyte material is used, for example, in an all-solid-state lithium ion secondary battery.

[0055] (Second Embodiment) Hereinafter, the second embodiment will be described. Matters described in the first embodiment will be omitted as appropriate.

[0056] FIG. 4 is a flowchart showing an example of the production method according to the second embodiment.

[0057] In the production method according to the second embodiment, the firing step S1000 includes a first firing step S1001 and a second firing step S1002. The second firing step S1002 is executed after the first firing step S1001.

[0058] In the first firing step S1001, the mixed material is fired at the first firing temperature T1. In the second firing step S1002, the mixed material is fired at the second firing temperature T2. Here, the second firing temperature T2 is 350°C or higher and is higher than the first firing temperature T1.

[0059] The manufacturing method according to the second embodiment is an industrially highly productive method for manufacturing a halide having higher ionic conductivity.

[0060] Hereinafter, the manufacturing method according to the second embodiment will be described using an example in which the mixed material contains Y2O3 and Gd2O3.

[0061] In the first firing step S1001, Y2O3, Gd2O3, and NH4α react with each other at the first firing temperature T1. That is, Y2O3 and Gd2O3 are halogenated. In the second firing step S1002, at the second firing temperature T2, the halogenated Y2O3 and Gd2O3 react with Liβ and Caγ2. As a result, the fired halide has higher crystallinity. As a result, the ionic conductivity of the fired halide can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0062] In order to manufacture a halide having higher ionic conductivity by an industrially highly productive method, the first firing temperature T1 may be 160°C or higher and less than 350°C. When the first firing temperature T1 is 160°C or higher, the mixed material can react sufficiently. That is, Y2O3, Gd2O3, and NH4γ can react sufficiently. When the first firing temperature T1 is less than 350°C, the sublimation of NH4γ can be suppressed. Thereby, the ionic conductivity of the fired halide can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0063] In order to produce a halide having a higher ionic conductivity by an industrially highly productive method, the second firing temperature T2 may be 350 °C or higher and 700 °C or lower. By setting the second firing temperature T2 to 350 °C or higher, the mixed materials can react sufficiently. That is, the compound containing Y, the compound containing Gd, NH4α, Liβ, and Caγ2 can react sufficiently. As a result, the halide as the fired product has higher crystallinity. When the second firing temperature T2 is 700 °C or lower, thermal decomposition of the halide generated by the solid-phase reaction can be suppressed. Thereby, the ionic conductivity of the halide as the fired product can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0064] FIG. 5 is a diagram showing an example of a firing temperature profile of the manufacturing method according to the second embodiment.

[0065] As shown in FIG. 5, in the first firing step S1001, the mixed materials may be fired during the first firing time P1. In the second firing step S1002, the mixed materials may be fired during the second firing time P2.

[0066] In order to produce a halide having a higher ionic conductivity by an industrially highly productive method, the first firing time P1 may be 1 hour or longer and 72 hours or shorter. When the first firing time P1 is 1 hour or longer, the mixed materials (that is, Y2O3, Gd2O3, and NH4α) can react sufficiently. When the first firing time P1 is 72 hours or shorter, volatilization of "the reactant of Y2O3 and NH4α" and "the reactant of Gd2O3 and NH4α" can be suppressed. That is, a halide having the target composition ratio can be obtained. As a result, a decrease in the ionic conductivity of the halide due to compositional deviation can be suppressed. That is, a higher-quality halide solid electrolyte material can be obtained.

[0067] In order to produce a halide having higher ionic conductivity by an industrially highly productive method, the second firing time P2 may be 1 hour or more and 72 hours or less. When the second firing time P2 is 1 hour or more, the mixed materials can react sufficiently. That is, the compound containing Y, the compound containing Gd, NH4α, Liβ, and Caγ2 can react sufficiently. When the second firing time P2 is 72 hours or less, volatilization of the fired halide can be suppressed. That is, a halide having the target composition ratio can be obtained. As a result, a decrease in the ionic conductivity of the halide due to compositional deviation can be suppressed. That is, a higher-quality halide solid electrolyte material can be obtained.

[0068] P1 > P2 may be satisfied. That is, the first firing time P1 may be longer than the second firing time P2. Thereby, a halide having higher ionic conductivity can be produced by an industrially highly productive method.

[0069] In the first firing step S1001, the mixed materials (that is, Y2O3, Gd2O3, and NH4α) can react sufficiently at the first firing temperature T1 and during the first firing time P1. That is, Y2O3 and Gd2O3 can be halogenated sufficiently. Next, in the second firing step S1002, the sufficiently halogenated Y2O3 and Yδ3, and the sufficiently halogenated Gd2O3 and Gdε3 react with Liβ and Caγ2 at the second firing temperature T2 and during the second firing time P2. Thereby, the fired halide has higher crystallinity. As a result, the ionic conductivity of the fired halide can be increased. That is, a high-quality halide solid electrolyte material can be obtained.

[0070] In the first firing step S1001, (NH4) a Yα 3+a (0 ≤ a ≤ 3) may be synthesized from Y2O3 and NH4α. (NH4) b Gdα 3+b (0 ≤ b ≤ 3) may be synthesized from Gd2O3 and NH4α.

[0071] In the second firing step S1002, (NH4) a Yα 3+a and (NH4) b Gdα 3+b may be reacted with Liβ and Caγ2 to obtain a halide (i.e., a solid electrolyte material).

[0072] For example, from Y2O3, Gd2O3, NH4Cl, LiCl, and CaCl2, Li 2.8 Ca 0.1 Y 0.5 Gd 0.5 Cl6 is synthesized. Here, the first firing temperature T1 is about 200 °C, and the second firing temperature T2 is about 500 °C. In this case, in the first firing step S1001, NH4Cl does not sublime and reacts with Y2O3 and Gd2O3 to form (NH4) a YCl 3+a (0 ≦ a ≦ 3) and (NH4) b GdCl 3+b (0 ≦ b ≦ 3) are mainly formed. Then, in the second firing step S1002, (NH4) a YCl 3+a and (NH4) b GdCl 3+b react with LiCl and CaCl2 to obtain a halide solid electrolyte material with high crystallinity. In this way, a halide solid electrolyte material with high ionic conductivity is obtained.

[0073] The firing step S1000 may include not only the first firing step S1001 and the second firing step S1002 but also another firing step. That is, the firing step S1000 may include a firing step of three or more stages according to the type of raw material or the number of raw materials.

Example

[0074] Hereinafter, the present disclosure will be described in more detail.

[0075] In the following, the halide produced by the manufacturing method of the present disclosure was evaluated as a solid electrolyte material.

[0076] <Sample 1> (Preparation of solid electrolyte material) - In an argon atmosphere having a dew point of 60°C or lower and an oxygen concentration of 0.0001% by volume or lower (hereinafter referred to as "dry argon atmosphere"), Y2O3, Gd2O3, NH4Cl, LiCl, LiBr, and CaBr2 were prepared as raw material powders so as to have a molar ratio of Y2O3:Gd2O3:NH4Cl:LiCl:LiBr:CaBr2 = 0.25:0.25:6.6:0.5:2.35:0.075. These materials were pulverized and mixed in an agate mortar. The obtained mixture was placed in an alumina crucible and fired at 500°C for 1 hour under a nitrogen atmosphere. That is, both the firing temperatures T1 and T2 were 500°C. The obtained fired product was pulverized in an agate mortar. In this way, a solid electrolyte material using Sample 1 containing Li, Ca, Y, Gd, Br, and Cl was obtained.

[0077] (Evaluation of ionic conductivity) FIG. 6 shows a schematic diagram of a pressure molding die 200 used for evaluating the ionic conductivity of a solid electrolyte material.

[0078] The pressure molding die 200 included a punch upper part 201, a frame mold 202, and a punch lower part 203. The frame mold 202 was formed of insulating polycarbonate. The punch upper part 201 and the punch lower part 203 were formed of electronically conductive stainless steel.

[0079] Using the pressure molding die 200 shown in FIG. 6, the impedance of the solid electrolyte material using Sample 1 was measured by the following method.

[0080] In a dry argon atmosphere, the powder of the solid electrolyte material by Sample 1 was filled inside the pressure molding die 200. Inside the pressure molding die 200, a pressure of 300 MPa was applied to the solid electrolyte material by Sample 1 using the upper punch 201 and the lower punch 203.

[0081] While the pressure was applied, the upper punch 201 and the lower punch 203 were connected to a potentiostat (Princeton Applied Research, VersaSTAT4) equipped with a frequency response analyzer. The upper punch 201 was connected to the working electrode and the terminal for potential measurement. The lower punch 203 was connected to the counter electrode and the reference electrode. The impedance of the solid electrolyte material was measured at room temperature by the electrochemical impedance measurement method.

[0082] Figure 7 is a graph showing the Cole-Cole plot obtained by impedance measurement of the solid electrolyte material by Sample 1.

[0083] In Figure 7, the real value of the impedance at the measurement point where the absolute value of the phase of the complex impedance is the smallest was regarded as the resistance value for the ion conduction of the solid electrolyte material. For the real value, refer to the arrow R shown in Figure 7. SE Using the resistance value, the ionic conductivity was calculated based on the following formula (3). σ=(R SE ×S / t) -1 ···· (3) Here, σ represents the ionic conductivity. S represents the contact area of the solid electrolyte material with the upper punch 201 (equal to the cross-sectional area of the hollow part of the frame type 202 in Figure 6). R represents the resistance value of the solid electrolyte material in the impedance measurement. t represents the thickness of the solid electrolyte material (that is, in Figure 6, the thickness of the layer formed from the powder 101 of the solid electrolyte material).

[0084] The ionic conductivity of the solid electrolyte material by Sample 1 measured at 25°C was 2.5×10 -3 S / cm.

[0085] <From Sample 2 to 24> (Fabrication of Solid Electrolyte Material) For Samples 2 to 7 and 24, except for the firing temperature, solid electrolyte materials were obtained from Samples 2 to 7 and 24 in the same manner as Sample 1. The firing temperatures are shown in Table 1.

[0086] For Samples 8 to 18 and 23, firing was performed in two steps instead of firing at 500°C for 1 hour in Sample 1. The mixture of raw material powders was fired at temperature T1 for 15 hours and then at temperature T2 for 1 hour. Except for the above matters, solid electrolyte materials were obtained from Samples 8 to 18 and 23 in the same manner as Sample 1. The values of temperatures T1 and T2 are shown in Table 1.

[0087] In Sample 19, in a dry argon atmosphere, Y2O3, Gd2O3, NH4Br, LiCl, and CaCl2 were prepared as raw material powders so as to have a molar ratio of Y2O3:Gd2O3:NH4Br:LiCl:CaCl2 = 0.25:0.25:6.6:2.85:0.075. These materials were ground and mixed in an agate mortar. The obtained mixture was placed in an alumina crucible and fired at 240°C for 15 hours and then at 500°C for 1 hour under a nitrogen atmosphere. The obtained fired product was ground in an agate mortar. In this way, a solid electrolyte material was obtained from Sample 19.

[0088] In Sample 20, Y2O3, Gd2O3, NH4Br, LiBr, and CaBr2 were prepared as raw material powders so as to have a molar ratio of Y2O3:Gd2O3:NH4Br:LiBr:CaBr2 = 0.25:0.25:6.6:2.85:0.075. Except for the above matters, a solid electrolyte material was obtained from Sample 20 in the same manner as Sample 19.

[0089] In Sample 21, Y2O3, GdCl3, NH4Cl, LiCl, LiBr, and CaBr2 were prepared as raw material powders in a dry argon atmosphere so that the molar ratio was Y2O3:GdCl3:NH4Cl:LiCl:LiBr:CaBr2 = 0.25:0.25:3.3:0.5:2.35:0.075. These materials were ground and mixed in an agate mortar. The resulting mixture was placed in an alumina crucible and fired at 200 °C for 15 hours and then at 500 °C for 1 hour under a nitrogen atmosphere. The obtained fired product was ground in an agate mortar. In this way, a solid electrolyte material according to Sample 21 was obtained.

[0090] In Sample 22, YCl3, Gd2O3, NH4Cl, LiCl, LiBr, and CaBr2 were prepared as raw material powders so that the molar ratio was YCl3:Gd2O3:NH4Cl:LiCl:LiBr:CaBr2 = 0.25:0.25:3.3:0.5:2.35:0.075. Except for the above matters, a solid electrolyte material according to Sample 22 was obtained in the same manner as Sample 21.

[0091] (Evaluation of ionic conductivity) The ionic conductivities of the solid electrolyte materials according to Samples 2 to 24 were measured in the same manner as Sample 1. The measurement results are shown in Table 1.

[0092] In Table 1, Raw material 1 is an oxide or halide containing Y. Raw material 2 is an oxide or halide containing Gd. Raw material 3 is ammonium halide. Raw material 4 is LiCl. Raw material 5 is LiBr. Raw material 6 is a halide containing Ca.

[0093]

Table 1

[0094] <Discussion> As is clear from Samples 1 to 24, the obtained solid electrolyte materials have an ionic conductivity of 3.0×10 -9 S / cm or more.

[0095] As is clear from Samples 8 to 22, even when the firing process is divided into two steps, the obtained solid electrolyte material has high ionic conductivity.

[0096] As is clear from comparing Samples 1 to 22 with Samples 23 and 24, when the process includes a step with a firing temperature of 350°C or higher, the obtained solid electrolyte material has even higher ionic conductivity. As is clear from comparing Samples 1 and 4 to 7 with Samples 2 and 3, if the firing temperature is 450°C or higher and 650°C or lower, the ionic conductivity of the solid electrolyte material becomes even higher. As is clear from comparing Samples 8, 9, and 12 to 22 with Samples 10 and 11, even when the firing process is in two steps, if the second firing temperature T2 is 450°C or higher and 650°C or lower, the ionic conductivity of the solid electrolyte material becomes even higher.

[0097] As described above, the solid electrolyte material produced by the manufacturing method of the present disclosure has high lithium ion conductivity. Furthermore, the manufacturing method of the present disclosure is a simple method and an industrially highly productive method. An industrially highly productive method is, for example, a method that can be produced in large quantities at low cost.

Industrial Applicability

[0098] The manufacturing method of the present disclosure is used, for example, as a manufacturing method for solid electrolyte materials. The solid electrolyte material produced by the manufacturing method of the present disclosure is used, for example, in all-solid-state lithium ion secondary batteries.

Explanation of Signs

[0099] 101 Powder of solid electrolyte material 200 Pressing die 201 Upper punch 202 Frame type 203 Lower punch

Claims

1. A method for manufacturing a halide, wherein A compound containing Y, a compound containing Gd, NH 4 α, Liβ, and Caγ 2 The firing process includes firing the mixed material containing these in an inert gas atmosphere. Here, the halide to be manufactured contains α, β, and γ, The compound containing Y is Y 2 O 3 and Yδ 3 and is at least one selected from the group consisting of The compound containing Gd is Gd 2 O 3 and at least one selected from the group consisting of Gdε 3 and is at least one selected from the group consisting of The mixed material is Y 2 O 3 and Gd 2 O 3 and includes at least one selected from the group consisting of α, β, γ, δ, and ε are each independently at least one selected from the group consisting of F, Cl, Br, and I, in the firing step, the mixed material is fired at 350°C or higher and 700°C or lower for 1 hour or longer and 72 hours or shorter, A method for manufacturing a halide.

2. The mixed material is Y 2 O 3 , Gd 2 O 3 , NH 4 α, Liβ, and Caγ 2 and includes The manufacturing method according to Claim 1.

3. in the firing step, the mixed material is fired at 650°C or lower, The manufacturing method according to Claim 1.

4. the firing step includes a first firing step and a second firing step performed after the first firing step, in the first firing step, the mixed material is fired at a first firing temperature T1, in the second firing step, the mixed material is fired at a second firing temperature T2, the first firing temperature T1 is 160°C or higher and lower than 350°C, the second firing temperature T2 is 350°C or higher and 700°C or lower, in the first firing step, the mixed material is fired for 1 hour or longer and 72 hours or shorter, in the second firing step, the mixed material is fired for 1 hour or longer and 72 hours or shorter, the time for firing the mixed material in the first firing step is longer than the time for firing the mixed material in the second firing step, The manufacturing method according to Claim 1 or 2.

5. α, β, γ, δ, and ε are each independently at least one selected from the group consisting of Cl and Br, The manufacturing method according to any one of Claims 1 to 4.

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