Lithium nitride manufacturing device and lithium nitride manufacturing method

Abstract

The lithium nitride manufacturing device (10) of the present invention is used to manufacture lithium nitride by heating a lithium component (9) in a nitrogen environment to nitride the lithium component (9), wherein the lithium nitride manufacturing device (10) comprises: a reaction tank (1) for performing a nitridation reaction of the lithium component (9); a heating mechanism (2) for heating the lithium component (9); an environmental control mechanism (3) for controlling the dew point in the reaction tank (1); and an environmental cooling mechanism (4) for cooling the reaction tank (1).

Description

Technical Field

[0001] The invention relates to a lithium nitride manufacturing device and a lithium nitride manufacturing method. Background Art

[0002] Lithium nitride has a lithium ion conductivity of 10 at room temperature. -3 Scm -1 It is widely known as a high ion conductor and is being studied for use as a solid electrolyte or electrode material for lithium-ion batteries.

[0003] Since lithium nitride is easily decomposed when in contact with water, its synthesis method is subject to many restrictions. Lithium nitride is usually produced by the reaction of metallic lithium and nitrogen.

[0004] Patent document 1 (Japanese Patent Application Publication No. 2001-48504) discloses a method for producing lithium nitride, characterized in that metallic lithium is reacted with nitrogen in a nitrogen environment while the temperature of lithium and the generated lithium nitride is maintained below the melting temperature of lithium by cooling.

[0005] Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-3209) discloses a method for producing lithium nitride, which includes heating metallic lithium from 50°C to 110°C at a heating rate of 0.4°C / min to 7.0°C / min in a nitrogen atmosphere.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2001-48504

[0009] Patent Document 2: Japanese Patent Application Publication No. 2002-3209 Summary of the invention

[0010] Problems to be solved by the invention

[0011] However, the present inventors' research has revealed that in the methods for producing lithium nitride by reacting metallic lithium with nitrogen gas disclosed in Patent Documents 1 and 2, the reaction reproducibility between metallic lithium and nitrogen gas is poor and the nitridation reaction may not proceed.

[0012] The present invention has been made in view of the above circumstances, and provides a lithium nitride manufacturing apparatus and a lithium nitride manufacturing method that can rapidly generate lithium nitride and stably produce lithium nitride.

[0013] Technical solutions to problems

[0014] According to the present invention, there is provided a lithium nitride manufacturing apparatus for manufacturing lithium nitride by heating a lithium component in a nitrogen atmosphere to nitride the lithium component, wherein:

[0015] The lithium nitride manufacturing device comprises:

[0016] A reaction tank for performing a nitridation reaction of the lithium component;

[0017] A heating mechanism for heating the lithium component;

[0018] An environmental control mechanism for controlling the dew point in the reaction tank; and

[0019] An environmental cooling mechanism is used to cool the interior of the reaction tank.

[0020] In addition, according to the present invention, a method for producing lithium nitride is provided, which is used to produce lithium nitride, wherein:

[0021] The method for producing lithium nitride comprises:

[0022] Step (A): placing a lithium component in the reaction tank of the lithium nitride manufacturing device; and

[0023] Step (B): The reaction tank is set to a nitrogen atmosphere, and while the dew point and temperature in the reaction tank are controlled by the environment control mechanism and the environment cooling mechanism, the lithium member is heated by the heating mechanism to nitride the lithium member.

[0024] Effects of the Invention

[0025] According to the present invention, it is possible to provide a lithium nitride manufacturing apparatus and a lithium nitride manufacturing method that can rapidly generate lithium nitride and stably produce lithium nitride. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a cross-sectional view schematically showing an example of the structure of a lithium nitride production apparatus according to an embodiment of the present invention.

[0027] Figure 2 This is a cross-sectional view schematically showing an example of the structure of a lithium nitride production apparatus according to an embodiment of the present invention.

[0028] Figure 3 This is a cross-sectional view schematically showing an example of the structure of a lithium nitride production apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following is an explanation of the embodiments of the present invention using the accompanying drawings. It should be noted that in all the drawings, the same structural components are marked with common reference numerals, and the description is appropriately omitted. In addition, the drawings are conceptual drawings and are inconsistent with the actual size ratio. In addition, unless otherwise specified, the numerical range "A to B" means above A and below B.

[0030] (Lithium Nitride Manufacturing Equipment)

[0031] Figure 1 to Figure 3 It is a cross-sectional view schematically showing an example of the structure of a lithium nitride production apparatus 10 according to an embodiment of the present invention.

[0032] The lithium nitride manufacturing device 10 of the present embodiment is a lithium nitride manufacturing device 10 for manufacturing lithium nitride by heating a lithium component 9 in a nitrogen environment to nitride the lithium component 9, and comprises: a reaction tank 1 for performing a nitridation reaction of the lithium component 9; a heating mechanism 2 for heating the lithium component 9; an environmental control mechanism 3 for controlling the dew point in the reaction tank 1; and an environmental cooling mechanism 4 for cooling the reaction tank 1.

[0033] According to the lithium nitride production apparatus 10 of the present embodiment, lithium nitride can be generated rapidly and can be produced stably.

[0034] As described above, the present inventors' research has revealed that in the methods for producing lithium nitride by reacting metallic lithium with nitrogen gas disclosed in Patent Documents 1 and 2, the reproducibility of the reaction between metallic lithium and nitrogen gas is poor and the nitridation reaction may not proceed.

[0035] Therefore, as a result of intensive research, the inventors discovered that by controlling the dew point in the reaction tank 1 using an environmental control mechanism 3 for controlling the dew point in the reaction tank 1 and an environmental cooling mechanism 4 for cooling the reaction tank 1 while using a heating mechanism 2 to heat the lithium component 9 in a nitrogen environment, the nitridation reaction of the lithium component can be carried out quickly.

[0036] It is considered that the formation of a film containing lithium oxide and lithium hydroxide on the surface of metal lithium can be suppressed by controlling the dew point in the reaction tank 1. Therefore, it is considered that the contact area between metal lithium and nitrogen increases and the nitridation reaction of the lithium member proceeds rapidly.

[0037] The reaction tank 1 is not particularly limited as long as it can carry out the nitridation reaction of the lithium component 9 and can maintain the dew point, nitrogen environment, and ambient temperature (temperature inside the reaction tank 1), but examples thereof include reaction tanks formed of heat-resistant materials, glove boxes, dryers, vacuum replacement dryers, metal sealed tanks, etc.

[0038] The shape and size of the reaction vessel 1 are not particularly limited, but can be appropriately determined according to the amount of lithium member 9 to be processed.

[0039] The heating mechanism 2 is not particularly limited, and for example, known heating mechanisms such as heating wires, lamp heating, high-frequency induction heating, and microwave heating can be used. However, as described later, it is preferable to include a local heating mechanism that can locally heat the lithium member 9 .

[0040] Examples of the environmental control mechanism 3 for controlling the dew point in the reaction tank 1 include a column filled with a moisture adsorbent such as a molecular sieve, a steam trap through which a refrigerant flows, a honeycomb coated with a water-absorbing material such as LiCl, and a column filled with phosphorus pentoxide. The nitrogen in the reaction tank 1 is circulated through the environmental control mechanism 3, thereby removing moisture from the nitrogen and controlling the dew point in the reaction tank 1.

[0041] Examples of the environment cooling mechanism 4 for cooling the inside of the reaction tank 1 include a heat exchanger connected to an air-cooling type solvent circulation device and a heat exchanger connected to a refrigerant type solvent circulation device.

[0042] In addition, as required, in the lithium nitride manufacturing apparatus 10 of this embodiment, Figure 1 As shown, a powder supply mechanism 5 for supplying inorganic particles to the surface of the lithium member 9 and a rolling mechanism 6 for embedding the inorganic particles attached to the surface of the lithium member 9 into the lithium member 9 may be further provided.

[0043] Thus, the inorganic particle-buried lithium member 9 described later can be manufactured in the lithium nitride manufacturing apparatus 10 , and the nitridation reaction can be performed in the lithium nitride manufacturing apparatus 10 without exposing the obtained inorganic particle-buried lithium member 9 to the atmosphere.

[0044] Examples of the powder supply mechanism 5 include a vibration feeder, a plate feeder, a screw feeder, and the like.

[0045] In addition, as required, in the lithium nitride manufacturing apparatus 10 of this embodiment, Figure 1 As shown, a gas supply unit 7 for introducing nitrogen gas into the reaction tank 1 may be provided. As a result, the reaction tank 1 is filled with fresh nitrogen gas, so that the nitridation reaction of the lithium component 9 can be performed more quickly. Furthermore, the reaction tank 1 is negatively pressurized, so that the atmosphere can be prevented from flowing into the reaction tank 1.

[0046] In addition, as required, in the lithium nitride manufacturing apparatus 10 of this embodiment, Figure 1 As shown, a gas discharge unit 8 for discharging nitrogen gas in the reaction tank 1 may be further provided. This can suppress the pressure in the reaction tank 1 from increasing and placing a burden on the reaction tank 1 .

[0047] In addition, the positions of the gas supply part 7 and the gas discharge part 8 in the reaction tank 1 are not particularly limited.

[0048] In addition, in the lithium nitride manufacturing apparatus 10 of the present embodiment, Figure 2 As shown, the structure may further include at least one selected from the conveying mechanism 11, the cutting mechanism 12, and the lithium member roller 13.

[0049] Thus, the lithium member 9 fed from the lithium member roller 13 can be cut into an appropriate size by the cutting mechanism 12, and the cut lithium member 9 can be transported to the heating mechanism 2 by the conveying mechanism 11. In addition, inorganic particles can be supplied to the surface of the lithium member 9 by the powder supply mechanism 5 during the conveying mechanism 11, and then the inorganic particles can be embedded in the lithium member 9 by the rolling mechanism 6. In this way, the process of manufacturing the lithium member 9 embedded with the inorganic particles and the process of heating the lithium member 9 embedded with the inorganic particles can be continuously performed.

[0050] As the conveying mechanism 11, for example, a belt conveyor or the like can be cited.

[0051] In addition, if Figure 3 As shown, the lithium nitride production apparatus 10 of the present embodiment may also have a structure further including a lithium member roller 13 and a lithium nitride roller 14 .

[0052] Thus, the lithium member 9 fed from the lithium member roller 13 can be transported to the lithium nitride roller 14 disposed on the heating mechanism 2. In addition, inorganic particles can be supplied to the surface of the lithium member 9 using the powder supply mechanism 5 during the transport from the lithium member roller 13 to the lithium nitride roller 14, and then the inorganic particles can be continuously embedded in the lithium member 9 using the rolling mechanism 6. In this way, the process of manufacturing the lithium member 9 embedded with the inorganic particles and the process of heating the lithium member 9 embedded with the inorganic particles can be continuously performed.

[0053] In addition, if Figure 3 As shown, the lithium nitride production apparatus 10 of the present embodiment may be configured to further include a heat storage cover 15 that covers the vicinity of the heating mechanism 2 .

[0054] Thus, even when the temperature of the lithium member 9 disposed in the reaction tank 1 is increased, a rise in the ambient temperature of the reaction tank 1 can be suppressed, and as a result, a rise in the dew point in the reaction tank 1 can be suppressed.

[0055] (Method for producing lithium nitride)

[0056] Next, a method for producing lithium nitride according to the present embodiment will be described.

[0057] The method for producing lithium nitride of the present embodiment is a method for producing lithium nitride, for example, including the following steps (A) and (B). In addition, the method for producing lithium nitride of the present embodiment may further include the following steps (C) and (D) as needed.

[0058] Step (A): a step of disposing a lithium member 9 in the reaction tank 1 of the lithium nitride production apparatus 10 of the present embodiment;

[0059] Step (B): a step of nitriding the lithium member 9 by making the reaction tank 1 a nitrogen atmosphere and heating the lithium member 9 by using the heating mechanism 2 while controlling the dew point and temperature in the reaction tank 1 by using the environment control mechanism 3 and the environment cooling mechanism 4;

[0060] Step (C): Before step (B), a step of embedding inorganic particles into the lithium member 9;

[0061] Step (D): After step (B), a step of pulverizing the nitrided lithium member 9 into powder.

[0062] (Process (A))

[0063] In step (A), the lithium member 9 is disposed in the reaction vessel 1 of the lithium nitride production apparatus 10 of the present embodiment.

[0064] The lithium component 9 of the present embodiment is, for example, a metal lithium having a thin film composed of carbon and oxygen on its surface, and its shape may be a shape generally provided by ingots, foils, wires, rods, etc., and does not need to be a special shape. However, since a shape with a large surface area is preferred for rapidly completing the nitriding reaction, a foil is preferably used as the shape of the lithium component 9. That is, the lithium component 9 of the present embodiment is preferably a metal lithium foil.

[0065] The thickness of the metal lithium foil is preferably 3 mm or less, more preferably 1 mm or less. When the thickness of the metal lithium foil is below the above upper limit, the explosive reaction caused by the accumulation of reaction heat can be suppressed. The thickness of the metal lithium foil is not particularly limited, for example, it can be 0.05 mm or more, or it can be 0.1 mm or more.

[0066] (Process (B))

[0067] In step (B), the reaction vessel 1 is set to a nitrogen atmosphere, and the lithium member 9 is heated by the heating mechanism 2 while the dew point and temperature in the reaction vessel 1 are controlled by the environment control mechanism 3 and the environment cooling mechanism 4 , so that the lithium member 9 is nitrided.

[0068] From the viewpoint of more rapidly performing the nitriding reaction of the lithium member 9, the dew point in the reaction tank in step (B) is preferably less than 0° C., more preferably less than -10° C., further preferably less than -15° C., further preferably less than -18° C., further preferably less than -20° C., further preferably less than -25° C., further preferably less than -30° C., further preferably less than -40° C., further preferably less than -50° C. The lower limit of the dew point is not particularly limited, and is, for example, not less than -90° C.

[0069] In the method for producing lithium nitride of the present embodiment, by heating the lithium member 9 in a nitrogen environment having a dew point lower than the upper limit value, the formation of a film containing lithium oxide or lithium hydroxide on the surface of the metal lithium can be suppressed. Therefore, the contact area between the metal lithium and nitrogen is increased, so that the nitridation reaction of the lithium member 9 can be carried out more quickly.

[0070] Nitrogen gas is used in the nitridation reaction of the lithium member 9. Nitrogen gas reacts easily with lithium, is inexpensive, and is non-toxic.

[0071] The lower the oxygen concentration in the nitrogen gas used, the more preferable it is. This is because when the oxygen concentration in the nitrogen gas increases, metallic lithium is significantly oxidized and corroded, which not only hinders the formation of lithium nitride but also causes lithium oxide or lithium hydroxide to mix into lithium nitride.

[0072] Specifically, the oxygen concentration in the nitrogen gas is preferably 100 ppm or less, more preferably 60 ppm or less.

[0073] In addition, the purity of nitrogen gas is preferably 99.99% or higher.

[0074] In step (B), the lithium member 9 is preferably heated using a local heating mechanism capable of locally heating the lithium member 9. That is, the heating mechanism 2 preferably includes a local heating mechanism capable of locally heating the lithium member 9.

[0075] It is preferred to use a local heating mechanism to locally heat the lithium member 9 or the periphery of the lithium member 9 disposed in the reaction tank 1, rather than heating the entire reaction tank 1. By doing so, since the temperature in the reaction tank 1 becomes difficult to rise, it is possible to suppress the evaporation of water attached to the moisture adsorbent, device, and apparatus, etc., such as the molecular sieve in the environmental control mechanism 3, thereby suppressing the dew point rise in the reaction tank 1. That is, by using a local heating mechanism that can locally heat the lithium member 9, the lithium member 9 can be heated while the dew point in the reaction tank 1 is maintained below the above-mentioned upper limit.

[0076] Examples of the local heating mechanism include conductive heat transfer heating and radiant heat transfer heating. These heating mechanisms may be used alone or in combination of two or more.

[0077] Conduction heat transfer heating is a method of heating a lithium member by heat conduction in which the lithium member is brought into contact with a high-temperature object. Examples of a device for conducting conduction heat transfer heating include a hot plate heater and a heating roller.

[0078] Radiant heat transfer heating is a method of heating a lithium member by causing it to absorb energy released by a high-temperature object in the form of electromagnetic waves. Examples of devices for radiant heat transfer heating include infrared heaters and infrared lamps.

[0079] In the method for producing lithium nitride of the present embodiment, from the viewpoint of more rapidly generating lithium nitride, the heating temperature of the heating mechanism 2 in step (B) is preferably 30° C. or higher, more preferably 40° C. or higher, and further preferably 45° C. or higher. The upper limit of the heating temperature of the heating mechanism 2 is not particularly limited, but from the viewpoint of suppressing an explosive reaction caused by the accumulation of reaction heat, it is preferably 120° C. or lower, more preferably 100° C. or lower, further preferably 80° C. or lower, and further preferably 60° C. or lower.

[0080] Here, the heating temperature of the heating mechanism 2 is a set temperature of the heating mechanism 2, that is, the temperature of the heating portion.

[0081] In the method for producing lithium nitride of the present embodiment, from the viewpoint of more rapidly generating lithium nitride, the substantial temperature of the lithium member 9 in step (B) is preferably 30° C. or higher, more preferably 40° C. or higher, and even more preferably 50° C. or higher. The upper limit of the substantial temperature of the lithium member 9 in step (B) is not particularly limited, but from the viewpoint of suppressing an explosive reaction caused by the accumulation of reaction heat, it is preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0082] Here, the substantial temperature of the lithium member 9 in the step (B) is the temperature of the surface of the lithium member 9 .

[0083] In the method for producing lithium nitride of the present embodiment, from the viewpoint of more rapidly generating lithium nitride, the ambient temperature of the nitrogen environment in step (B) is preferably 20° C. or higher, more preferably 23° C. or higher, further preferably 25° C. or higher, and further preferably 28° C. or higher. The upper limit of the ambient temperature of the nitrogen environment in step (B) is not particularly limited, but from the viewpoint of maintaining the dew point under the nitrogen environment in step (B) below the upper limit, it is preferably 40° C. or lower, more preferably 35° C. or lower, and further preferably 30° C. or lower.

[0084] Here, the ambient temperature of the nitrogen atmosphere in step (B) is the temperature of a space at a point 30 cm away from the heating portion of the heating mechanism 2 .

[0085] In the method for producing lithium nitride of the present embodiment, from the viewpoint of maintaining the dew point in the reaction tank 1 in the step (B) below the above-mentioned upper limit value, the ambient temperature in the reaction tank 1 is controlled using the ambient cooling mechanism 4 such as a heat exchanger. By doing so, even if the temperature of the lithium member 9 arranged in the reaction tank 1 for heating is increased, the rise in the ambient temperature of the reaction tank 1 in the step (B) can be suppressed, and as a result, the dew point in the reaction tank 1 in the step (B) can be effectively maintained below the above-mentioned upper limit value.

[0086] The time for the nitridation reaction of the lithium member 9 is, for example, 0.5 hours to 24 hours, preferably 0.5 hours to 8 hours, and more preferably 1 hour to 5 hours.

[0087] (Process (C))

[0088] In the method for producing lithium nitride of the present embodiment, a step of embedding inorganic particles in the lithium member 9 may be performed before step (B) as necessary. That is, in step (B), the lithium member 9 embedded with inorganic particles may be used.

[0089] By embedding the inorganic particles in the lithium component 9, the lithium component 9 is deformed, and fresh metal lithium is exposed around the contact portion between the lithium component 9 and the inorganic particles. When nitrogen contacts this portion, the exposed fresh metal lithium becomes a nitridation starting point, and the nitridation reaction of the lithium component can proceed more rapidly.

[0090] The inorganic particles of this embodiment are not particularly limited, and for example, lithium nitride powder, lithium sulfide powder, phosphorus sulfide powder, solid electrolyte powder, etc. can be used. From the viewpoint of obtaining high-purity lithium nitride and simplifying the removal process of the inorganic particles, lithium nitride powder is preferred as the inorganic particles.

[0091] The inorganic particles of the present embodiment are not particularly limited, and the average particle size d in the weight-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method is 50 The thickness is preferably 0.1 μm or more and 45 μm or less, and more preferably 0.5 μm or more and 20 μm or less.

[0092] By making the average particle size d 50 When the average particle size d of the inorganic particles is greater than the above lower limit, the handling properties of the inorganic particles can be improved. 50 When the content is equal to or less than the upper limit, the amount of nitridation starting point regions generated can be increased, and as a result, the nitridation reaction of the lithium component can be carried out more rapidly.

[0093] In the lithium component 9 embedded with inorganic particles, when the total of the inorganic particles and the lithium component 9 is 100 mass%, the embedding amount of the inorganic particles is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, and preferably 10 mass% or less, more preferably 5 mass% or less.

[0094] When the embedding amount of the inorganic particles is equal to or greater than the above lower limit, the amount of nitridation starting point regions generated can be increased, and as a result, the nitridation reaction of the lithium member can be carried out more rapidly.

[0095] When the amount of inorganic particles embedded is equal to or less than the upper limit value described above, an explosive reaction due to accumulation of reaction heat can be suppressed, and as a result, the nitridation reaction of the lithium member 9 can be performed more safely.

[0096] As a method of embedding inorganic particles in a part of the lithium member 9 , for example, there is a method of scattering inorganic particles on the surface of the lithium member and then pressing the lithium member 9 to which the inorganic particles are attached by a rolling mechanism 6 .

[0097] As the calendering mechanism 6, for example, a hand roller, a roller press, a flat plate press, etc. can be cited. Among them, a roller press is preferred. The roller press can continuously press and bond while applying a constant pressing pressure by setting the roller interval, and is preferred because it is suitable for mass production. As the material of the calendering mechanism 6, for example, polyacetal can be cited.

[0098] (Process (D))

[0099] As required, after step (B), the nitrided lithium member 9 is crushed into powder. Thus, powdered lithium nitride can be obtained. The method for making the powder is not particularly limited, and can be carried out by a generally known crushing mechanism. Step (D) can be carried out by setting the crushing mechanism in the reaction tank 1 and in the reaction tank 1, or by setting the crushing mechanism outside the reaction tank 1 and outside the reaction tank 1.

[0100] The lithium nitride obtained by the manufacturing method of this embodiment can be suitably used as, for example, a solid electrolyte for lithium ion batteries, an electrode material for lithium ion batteries, and an intermediate raw material for chemicals. Since the lithium nitride obtained by the manufacturing method of this embodiment is high-purity, it can be suitably used as a raw material for a solid electrolyte for lithium ion batteries and an electrode material for lithium ion batteries, which particularly require high purity.

[0101] As mentioned above, although embodiment of this invention was described, these are examples of this invention, and various structures other than the above-mentioned can be adopted.

[0102] Example

[0103] Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0104] (Example 1)

[0105] A hot plate heated to 50°C was set in a stainless steel vacuum replacement glove box in a nitrogen environment (dew point: -30°C, temperature: 25°C), and a metal lithium foil (manufactured by Honjo Metals, 60mm×250mm×1mm) with a purity of 99.7% was placed on the heated hot plate to start the nitridation reaction of the metal lithium foil. Here, a heat exchanger connected to an air-cooled solvent circulation device was used in the glove box to control the external air temperature (25°C). In addition, the nitrogen in the glove box was circulated through a column of a moisture adsorbent (manufactured by Wako Pure Chemical Industries, Ltd., molecular sieve 3A) to remove moisture from the nitrogen and keep the dew point in the glove box at -30°C. In addition, the nitrogen in the glove box was set to be automatically controlled by a pressure switch, and when the nitrogen was consumed in the nitridation reaction with the metal lithium foil and the internal pressure decreased, nitrogen equivalent to the consumed amount was introduced into the glove box.

[0106] Next, the nitridation rate was calculated from the weight change of the metal lithium foil. As a result, the nitridation rate after the metal lithium foil was placed on the hot plate for 2 hours was 83%.

[0107] Here, a nitridation rate of 100% means that all the metal lithium foil (Li) is converted into lithium nitride (Li 3 N).

[0108] (Example 2)

[0109] The nitridation reaction of the metal lithium foil was carried out in the same manner as in Example 1 except that the dew point of the nitrogen atmosphere was changed to -20°C. The nitridation rate after the metal lithium foil was placed on the hot plate for 5 hours was 80%.

[0110] (Example 3)

[0111] The nitridation reaction of the metal lithium foil was carried out in the same manner as in Example 1 except that the dew point of the nitrogen atmosphere was changed to -50°C. The nitridation rate after the metal lithium foil was placed on the hot plate for 2 hours was 90%.

[0112] (Example 4)

[0113] 80 mg of lithium nitride powder was sprinkled on both sides of a metal lithium foil with a purity of 99.7% (manufactured by Honjo Metals Co., Ltd., 60 mm×250 mm×1 mm, 8 g). Then, a hand roller was used to bury the lithium nitride powder adhering to the metal lithium foil into the surface layer of the metal lithium foil.

[0114] Next, a hot plate heated to 50°C is set in a stainless steel vacuum replacement glove box in a nitrogen environment (dew point: -30°C, temperature: 25°C), and the above-mentioned metal lithium foil with lithium nitride powder buried in the surface is arranged on the heated hot plate to start the nitridation reaction of the metal lithium foil. Here, a heat exchanger connected to an air-cooled solvent circulation device is used in the glove box to control the external air temperature (25°C). In addition, the nitrogen in the glove box is circulated through a column of a moisture adsorbent (Wako Pure Chemical Industries, Ltd., molecular sieve 3A) to remove moisture from the nitrogen and keep the dew point in the glove box at -30°C. In addition, the nitrogen in the glove box is set to be automatically controlled by a pressure switch. When the nitrogen is consumed in the nitridation reaction with the metal lithium foil and the internal pressure decreases, nitrogen equivalent to the consumption is introduced into the glove box.

[0115] Next, the nitridation rate was calculated from the weight change of the metal lithium foil. As a result, the nitridation rate was 81% after 1 hour of placing the metal lithium foil on the hot plate, and 100% after 2 hours.

[0116] (Comparative Example 1)

[0117] Except that the metal lithium foil was not heated (ie, no hot plate was used), the metal lithium foil was nitrided in the same manner as in Example 1. The nitridation rate of the metal lithium foil after being placed in the glove box for 96 hours was 0%.

[0118] (Comparative Example 2)

[0119] The nitridation reaction of the metal lithium foil was carried out in the same manner as in Example 1 except that the heat exchanger connected to the air-cooling solvent circulation device was not used. The nitridation rate after the metal lithium foil was placed on the hot plate for 2 hours was 10%.

[0120] (Comparative Example 3)

[0121] The nitridation reaction of the metal lithium foil was carried out in the same manner as in Example 1, except that the operation of adjusting the dew point in the glove box by circulating the nitrogen in the glove box through a column of a moisture adsorbent (manufactured by Wako Pure Chemical Industries, Ltd., molecular sieve 3A) to remove moisture in the nitrogen was not performed. The nitridation rate of the metal lithium foil after placing it on a hot plate for 2 hours was 5%.

[0122] This application claims the benefit of priority based on Japanese patent application No. 2020-073635, filed on April 16, 2020, the disclosure of which is incorporated herein in its entirety.

[0123] Description of reference numerals:

[0124] 1 Reaction tank

[0125] 2 Heating mechanism

[0126] 3 Environmental control agencies

[0127] 4 Environmental cooling mechanism

[0128] 5 Powder supply mechanism

[0129] 6 Calendering mechanism

[0130] 7 Gas supply unit

[0131] 8 Gas exhaust part

[0132] 9 Lithium components

[0133] 10 Lithium nitride manufacturing equipment

[0134] 11 Conveying mechanism

[0135] 12 Cutting mechanism

[0136] 13 Lithium component roller

[0137] 14 Lithium Nitride Roller

[0138] 15 Heat storage cover

Claims

1. A lithium nitride manufacturing apparatus for manufacturing lithium nitride by heating a lithium component in a nitrogen atmosphere to nitride the lithium component, in, The lithium nitride manufacturing device comprises: a powder supply mechanism for supplying inorganic particles to the surface of the lithium component; A rolling mechanism for embedding the inorganic particles attached to the surface of the lithium member into the lithium member; A reaction tank for performing a nitridation reaction of the lithium component; A heating mechanism for heating the lithium component; An environmental control mechanism for controlling the dew point in the reaction tank; and An environmental cooling mechanism for cooling the interior of the reaction tank; The heating mechanism includes a local heating mechanism capable of locally heating the lithium member; The lithium member is nitrided by heating the lithium member using the heating mechanism while controlling the dew point and the temperature in the reaction tank using the environmental control mechanism and the environmental cooling mechanism, The heating mechanism is arranged in the reaction tank.

2. The lithium nitride manufacturing device according to claim 1, in, The lithium nitride manufacturing apparatus further includes a gas supply unit for introducing nitrogen gas into the reaction tank.

3. The lithium nitride manufacturing device according to claim 1 or 2, in, The lithium nitride manufacturing apparatus further includes a gas exhaust unit for exhausting nitrogen gas in the reaction tank.

4. The lithium nitride manufacturing device according to claim 1 or 2, in, The local heating mechanism includes at least one heating mechanism selected from conductive heat transfer heating and radiative heat transfer heating.

5. The lithium nitride manufacturing device according to claim 1 or 2, in, The ambient cooling mechanism includes a heat exchanger.

6. A method for producing lithium nitride, which is used to produce lithium nitride. in, The method for producing lithium nitride comprises: Step (A): placing a lithium member in the reaction tank of the lithium nitride production apparatus according to any one of claims 1 to 5; and Step (B): The reaction tank is set to a nitrogen atmosphere, and while the dew point and temperature in the reaction tank are controlled by the environment control mechanism and the environment cooling mechanism, the lithium member is heated by the heating mechanism to nitride the lithium member.

7. The method for producing lithium nitride according to claim 6, in, The dew point in the reaction tank in the step (B) is lower than 0°C.

8. The method for producing lithium nitride according to claim 6 or 7, in, The method for producing lithium nitride further comprises a step (C) of embedding inorganic particles in the lithium member before the step (B).

9. The method for producing lithium nitride according to claim 8, in, The inorganic particles are lithium nitride powder.

10. The method for producing lithium nitride according to claim 8, in, When the total amount of the inorganic particles and the lithium member is 100% by mass, The embedding amount of the inorganic particles is 0.1 mass % or more and 10 mass % or less.

11. The method for producing lithium nitride according to claim 6 or 7, in, The heating temperature of the heating means in the step (B) is 30° C. or higher.

12. The method for producing lithium nitride according to claim 6 or 7, in, The ambient temperature in the reaction tank in the step (B) is 20° C. or higher and 40° C. or lower.

13. The method for producing lithium nitride according to claim 6 or 7, in, The substantial temperature of the lithium member in the step (B) is 30° C. or higher.

14. The method for producing lithium nitride according to claim 6 or 7, in, The lithium component is a metal lithium foil.

15. The method for producing lithium nitride according to claim 14, in, The thickness of the metal lithium foil is less than 3 mm.

16. The method for producing lithium nitride according to claim 6 or 7, in, The method for producing lithium nitride further includes a step (D) of crushing the nitrided lithium component into a powder after the step (B).

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