JP2016160127A - Li ION CONDUCTIVE FINE PARTICLE AND PRODUCTION METHOD THEREOF, AMORPHOUS LiPON FINE PARTICLE AND PRODUCTION METHOD THEREFOR, PRODUCTION METHOD OF ELECTROLYTE LAYER AND ELECTRODE LAYER, LITHIUM ION SECONDARY BATTERY AND PRODUCTION METHOD THEREFOR - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide Li ion conductive fine particles having a LIPON layer at least on surfaces thereof.SOLUTION: Li ion conductive fine particles 13 include LiPOfine particles 11 and amorphous LIPON layers 12 formed at least on surfaces of the LiPOfine particles. In a production method of the fine particles 13, the LiPOfine particles 11 are housed in a vessel, an electrode opposite to the inner face of the vessel is provided, a nitrogen gas or a gas including nitrogen is introduced into the vessel, the inside of the vessel is evacuated, plasma is formed by supplying electric power between the electrode and the vessel, and the amorphous LIPON layers 12 are formed on the surfaces of the LiPOfine particles 11 by oscillating or rotating the vessel.SELECTED DRAWING: Figure 1

Description

  The present invention relates to Li ion conductive fine particles and a method for producing the same, amorphous LiPON fine particles and a method for producing the same, a method for producing an electrolyte layer and an electrode layer, a lithium ion secondary battery, and a method for producing the same.

  In recent years, electric vehicles that do not emit carbon dioxide have been expected due to global warming and energy problems. In this technology, a “secondary battery” that stores electricity is indispensable, and a high-capacity and light-weight “lithium ion secondary battery” is regarded as a promising candidate. However, current lithium ion secondary batteries using an organic electrolyte have a risk of explosion (internal pressure increase, runaway reaction) due to liquid leakage, ignition, or decomposition of the electrolyte. In addition, this type of lithium ion secondary battery has a charging voltage limited to around 4.2 V in order to prevent decomposition of the organic electrolyte. As a result, the cruising distance per charge in electric vehicles is limited to gasoline vehicles. Compared to short.

  From the above background, in recent years, “all-solid-state lithium ion secondary batteries” using a solid electrolyte that has no risk of ignition or explosion and can have a high capacity have attracted attention. Among these, thin-film all-solid-state lithium ion secondary batteries in which an electrolyte thin film and an electrode material thin film are laminated are under research and development and are currently in practical use. However, in the case of the thin film type, not only the capacity is low because the amount of the electrode material used is small, but there is also a problem of film peeling due to vibration. Therefore, although this type of all-solid-state lithium ion secondary battery is useful for application to a microdevice such as a self-supporting sensor, a memory, and a backup power supply for an RFID tag, it is difficult to use it for an electric vehicle.

      On the other hand, a bulk-type all-solid-state lithium ion secondary battery using a particulate electrode and an electrolyte material can have a high capacity and is resistant to vibration. Therefore, research aimed at application to electric vehicles has been conducted, and recently, it has been reported that a bulk type system using sulfide-based electrolyte fine particles exhibits relatively high battery characteristics (for example, non-patented). Reference 1). However, there are concerns about the generation of harmful gases (hydrogen sulfide) due to reaction with moisture in sulfide-based systems, and problems have been pointed out from the viewpoint of safety.

  Therefore, the practical application of bulk-type all-solid-state lithium ion secondary batteries using oxide-based electrolyte fine particles that do not generate harmful gases and have high safety is expected.

As a bulk type all solid lithium ion secondary battery using an oxide electrolyte thin film instead of fine particles, there is a lithium ion secondary battery using a thin film of lithium oxynitride phosphate (LiPON). Non-Patent Documents 2 and 3 disclose that this LiPON thin film can be prepared by reactive sputtering of Li ₃ PO ₄ under N ₂ flow. However, no method for preparing high ion conductive LiPON fine particles has been found.

K. Takada, Progress and prospective of solid-state lithium batteries, Acta Mater. 61 (2013) 759-770. B. Fleutot, B. Pecquenard, F. Le, Cras, B. Delis, H. Martinez, L. Dupont, D. Guy-Bouyssou, Characterization of all-solid-state Li / LiPONB / TiOS microbatteries produced at the pilot scale , J. Power Sources 196 (2011) 10289-10296. N. Suzuki, T. Inaba, T. Shiga, Electrochemical properties of LiPON films made from a mixed powder target of Li3PO4 and Li2O, Thin Solid Films 520 (2012) 1821-1825. K. Senevirathne, C.S.Day, M.D.Gross, A. Lachgar, N.A.W.Holzwarth, A new crystalline LiPON electrolyte: Synthesis, properties, and electronic structure, Solid State Ionics 233 (2013) 95-101.

One aspect of the present invention is to provide a Li ion conductive fine particle having a LiPON layer at least on its surface or a method for producing the same.
Another embodiment of the present invention is to provide amorphous LiPON fine particles or a method for producing the same.
Another embodiment of the present invention is to provide a method for producing a solid electrolyte layer or electrode layer having Li ion conductivity.
Another embodiment of the present invention is to provide a lithium ion secondary battery having a solid electrolyte layer or a method for manufacturing the lithium ion secondary battery.

Hereinafter, various aspects of the present invention will be described.
[1] Li ₃ PO ₄ fine particles,
An amorphous LiPON layer formed on at least the surface of the Li ₃ PO ₄ fine particles;
Li ion conductive fine particles characterized by comprising:
[2] Amorphous LiPON fine particles produced by nitriding Li ₃ PO ₄ fine particles to the inside.

  The reason why the amorphous LiPON layer is used is that the Li ion conductivity is deteriorated in the crystallized LiPON layer.

[3] In the above [1],
Li ion conductive fine particles, wherein the diameter of the Li ion conductive fine particles is 0.01 μm or more and 1000 μm or less.
[4] In the above [2],
Amorphous LiPON fine particles having a diameter of 0.01 μm or more and 1000 μm or less.

[5] In the above [1] or [3],
Having metal particles or metal film formed on the LiPON layer;
Li ion conductive fine particles, wherein the LiPON layer is exposed from the metal particles or the metal film.
[6] In the above [2] or [4],
Having metal particles or metal film formed on the surface of the amorphous LiPON fine particles,
The amorphous LiPON fine particles, wherein the surface of the amorphous LiPON fine particles is exposed from the metal particles or the metal film.

[7] The Li ion conductive fine particles according to [1] or [3] described above contain Li ₃ PO ₄ fine particles in a container, an electrode facing the inner surface of the container, and nitrogen in the container. Introducing a gas or a gas containing nitrogen, evacuating the inside of the container, supplying power between the electrode and the container to form plasma in the container, and swinging or rotating the container Thus, Li ion conductive fine particles are produced by forming an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles while stirring or rotating the Li ₃ PO ₄ fine particles in the container.
[8] The amorphous LiPON fine particles described in [2] or [4] above contain Li ₃ PO ₄ fine particles in a container, an electrode facing the inner surface of the container, and nitrogen gas or Introducing a gas containing nitrogen, evacuating the inside of the container, supplying power between the electrode and the container to form plasma in the container, and by pendulum operation or rotating the container, Amorphous LiPON fine particles produced by nitriding the Li ₃ PO ₄ fine particles to the inside while stirring or rotating the Li ₃ PO ₄ fine particles in the container.

[9] The Li ion conductive fine particles according to [1] or [3] above,
A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Which is manufactured using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. Li ion conductive fine particles characterized by controlling to form an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles while rotating.
[10] The amorphous LiPON fine particles according to the above [2] or [4]
A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Which is manufactured using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. Amorphous LiPON fine particles, wherein the Li ₃ PO ₄ fine particles are controlled to be nitrided to the inside while rotating.

[11] In the above [9],
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
Li ion conductive fine particles, wherein a DC voltage component in forming the plasma is −500 V or less.
[12] In the above [10],
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
Amorphous LiPON fine particles, wherein a DC voltage component in forming the plasma is −500 V or less.

[13] The Li ion conductive fine particles according to any one of [1], [3], [7], [9] and [11] above and a binder are mixed and hardened. To electrolyte layer.
[14] An electrolyte characterized by mixing and solidifying the amorphous LiPON fine particles according to any one of [2], [4], [8], [10] and [12] and a binder. layer.
[15] a first electrode layer;
A second electrode layer;
An electrolyte layer disposed between the first electrode and the second electrode;
Comprising
The electrolyte layer is obtained by mixing and solidifying the Li ion conductive fine particles according to any one of [1], [3], [7], [9] and [11] and a binder. A lithium ion secondary battery characterized by being.
[16] a first electrode layer;
A second electrode layer;
An electrolyte layer disposed between the first electrode and the second electrode;
Comprising
The electrolyte layer is obtained by mixing and solidifying the amorphous LiPON fine particles according to any one of [2], [4], [8], [10] and [12] and a binder. A lithium ion secondary battery characterized by the above.
[17] A mixture of the Li ion conductive fine particles according to any one of [1], [3], [7], [9], and [11] above and a conductive assistant that conducts electrons. A method for producing an electrode layer, characterized by solidifying.
[18] Mixing and solidifying the amorphous LiPON fine particles according to any one of the above [2], [4], [8], [10] and [12] and a conductive auxiliary agent for conducting electrons. A method for producing an electrode layer characterized by the above.
[19] In the above [17] or [18],
The method for producing an electrode layer, wherein the electrode layer contains a binder.
[20] In a method for manufacturing a lithium ion secondary battery having a first electrode layer and a second electrode layer,
The first electrode layer is manufactured by the electrode layer manufacturing method according to any one of claims 17 to 19,
A method for manufacturing a lithium ion secondary battery, wherein the second electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 17 to 19.

[21] A method for producing Li ion conductive fine particles, wherein an amorphous LiPON layer is formed at least on the surface of the Li ₃ PO ₄ fine particles by treating the Li ₃ PO ₄ fine particles with nitrogen plasma.
[22] Amorphous LiPON fine particles characterized by treating Li ₃ PO ₄ fine particles with nitrogen plasma and nitriding the Li ₃ PO ₄ fine particles to the inside.
[23] In the above [21],
Li ion conductive fine particles, wherein the diameter of the Li ion conductive fine particles is 0.01 μm or more and 1000 μm or less.
[24] In the above [22],
Amorphous LiPON fine particles having a diameter of 0.01 μm or more and 1000 μm or less.

[25] a step of containing Li ₃ PO ₄ fine particles in a container;
Disposing an electrode facing the inner surface of the container;
Introducing nitrogen gas or nitrogen-containing gas into the container;
Evacuating the container; and
An amorphous LiPON layer is formed on the surface of the Li ₃ PO ₄ fine particles in the container by supplying electric power between the electrode and the container to form a plasma in the container, and the pendulum operation or rotation of the container. Forming a step;
A method for producing Li ion conductive fine particles, comprising:
[26] A step of containing Li ₃ PO ₄ fine particles in a container;
Disposing an electrode facing the inner surface of the container;
Introducing nitrogen gas or nitrogen-containing gas into the container;
Evacuating the container; and
By supplying electric power between the electrode and the container to form plasma in the container, the Li ₃ PO ₄ fine particles in the container are nitrided to the inside by operating the pendulum or rotating the container. Forming amorphous LiPON fine particles with
A process for producing amorphous LiPON fine particles characterized by comprising:

[27] a container;
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Is a method for producing Li ion conductive fine particles using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. A method for producing Li ion conductive fine particles, characterized by controlling the formation of an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles while rotating.
[28] a container;
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Is a method for producing amorphous LiPON fine particles using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. A method for producing amorphous LiPON fine particles, characterized in that the Li ₃ PO ₄ fine particles are controlled to be nitrided to the inside while rotating.

[29] In the above [27],
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
A method for producing Li ion conductive fine particles, wherein a DC voltage component in forming the plasma is −500 V or less.
[30] In the above [28],
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
A method for producing amorphous LiPON fine particles, wherein a DC voltage component in forming the plasma is −500 V or less.

[31] In the above [27] or [29],
After forming an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles, forming metal particles or a metal film on the LiPON layer,
The LiPON layer is exposed from the metal particles or the metal film, and the method for producing Li ion conductive fine particles.
[32] In the above [28] or [30],
After forming the amorphous LiPON fine particles by nitriding the Li ₃ PO ₄ fine particles to the inside, forming metal particles or a metal film on the amorphous LiPON fine particles,
A method for producing amorphous LiPON fine particles, wherein the surface of the amorphous LiPON fine particles is exposed from the metal particles or the metal film.

[33] A mixture of Li ion conductive fine particles produced by the production method according to any one of [25], [27], [29] and [31], and a conductive auxiliary agent for conducting electrons. The electrode layer manufacturing method, wherein the electrode layer is hardened.
[34] Mixing amorphous LiPON fine particles produced by the production method according to any one of [26], [28], [30] and [32] above, and a conductive auxiliary agent for conducting electrons. A method for producing an electrode layer, characterized by solidifying.
[35] In the above [33] or [34],
The method for producing an electrode layer, wherein the electrode layer contains a binder.

[36] In a method of manufacturing a lithium ion secondary battery having a first electrode layer and a second electrode layer,
The first electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 33 to 35,
36. A method of manufacturing a lithium ion secondary battery, wherein the second electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 33 to 35.

According to one aspect of the present invention, it is an object to provide a Li ion conductive fine particle having a LiPON layer at least on its surface or a method for producing the same.
Another aspect of the present invention is to provide amorphous LiPON fine particles or a method for producing the same.
Another aspect of the present invention is to provide a method for producing a solid electrolyte layer or electrode layer having Li ion conductivity.
Another aspect of the present invention is to provide a lithium ion secondary battery having a solid electrolyte layer or a method for manufacturing the lithium ion secondary battery.

(A), (B), (C) is sectional drawing for demonstrating the manufacturing method of Li ion conductive fine particle which concerns on 1 aspect of this invention. (A) shows the plasma surface modification method and sputtering method used to produce the Li ion conductive fine particles and amorphous LiPON fine particles shown in FIG. 1, and to impart electron conductivity to the Li ion conductive fine particles and the amorphous LiPON fine particles. Sectional drawing which shows the outline of the plasma apparatus which can be used together, (B) is sectional drawing along the 8B-8B line shown to (A). (A) and (B) are cross-sectional views for explaining a method for producing Li-ion conductive fine particles having electron conductivity and amorphous LiPON fine particles according to one embodiment of the present invention. 1 is a cross-sectional view illustrating a lithium ion secondary battery according to one embodiment of the present invention. Untreated Li ₃ PO ₄ fine particles, and Li ₃ PO ₄ is a photograph of samples N ₂ plasma treatment 100 W microparticles. (I) XPS survey spectrum of (A) untreated and (B) N ₂ plasma treated sample (treatment time: 90 minutes), (II) N1s spectrum of N ₂ plasma treated sample. (A) is a cross-sectional TEM image and electron diffraction image of an untreated sample, and (B) is a cross-sectional TEM image and electron diffraction image of a N ₂ plasma treated sample (100 W, 90 minutes treatment). It is a figure which shows the processing time dependence of the film thickness of LiPON. (A) shows a Cole-Cole plot (measurement frequency: 5 Hz to 1 MHz) of an untreated sample measured by changing the press pressure and their fitting curves. (B) shows an N ₂ plasma treated sample (treatment conditions: It is a figure which shows the Cole-Cole plot (measurement frequency: 5 Hz-1 MHz) of 100 W and 60 minutes and those fitting curves. The untreated sample (●), and N ₂ plasma treated sample: is a diagram showing a (treatment time 60 minutes) (○) press pressure dependence of the ionic conductivity of. 60,90,120 min N ₂ plasma-treated Cole-Cole plot of a sample (measurement frequency: 5 Hz to 1 MHz) is a diagram showing a fitting curve. It is a figure which shows the relationship between plasma processing time and ion conductivity. N ₂ plasma treated samples (treatment time: 90 minutes) to qualify the Cu by sputtering (Ar gas pressure: 5 Pa, output: 50 W, sputtering time: 90 minutes) is a TEM image of the sample surface.

  Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments and examples below.

[Embodiment 1]
1A, 1B, and 1C are cross-sectional views for explaining a method for producing Li ion conductive fine particles and amorphous LiPON fine particles according to one embodiment of the present invention.

Crystalline Li ₃ PO ₄ fine particles 11 shown in FIG. 1 (A) are prepared. Next, nitrogen is introduced into the surface of the Li ₃ PO ₄ fine particles 11 by treating the Li ₃ PO ₄ fine particles 11 with nitrogen plasma. In this way, an amorphous LiPON layer 12 is formed on the surface of the Li ₃ PO ₄ fine particles 11 as shown in FIG. 1 (B). Further, depending on the processing conditions, the Li ₃ PO ₄ fine particles 11 are nitrided to the inside, and amorphous LiPON fine particles 14 as shown in FIG. 1 (C) can be produced.

The outer diameters of the Li ion conductive fine particles 13 and the amorphous LiPON fine particles 14 are preferably 0.01 μm or more and 1000 μm or less. The outer diameter here means the longest outer diameter of the Li ion conductive fine particles 13 and the amorphous LiPON fine particles 14. Further, each of the Li ₃ PO ₄ fine particles 11, the Li ion conductive fine particles 13, and the amorphous LiPON fine particles 14 is not limited to a spherical shape, and may have any shape.

  According to the present embodiment, it is possible to produce fine particles 13 and 14 having high Li ion conductivity. In addition, the fine particles 13 and 14 having Li ion conductivity can be used not only as a solid electrolyte, but also by adding them to the electrode layer, a good Li ion conduction path can be constructed in the electrode.

In this embodiment, if it has a LiPON layer 12 surface of the amorphous Li ₃ PO ₄ fine particles 11, to Li ₃ PO ₄ particles 11 therein may remain, Li ₃ PO ₄ particles All 11 may be amorphous LiPON layers.

[Embodiment 2]
FIG. 2 (A) is a cross-sectional view schematically showing a plasma apparatus that can be used in combination with the plasma surface modification method and the sputtering method used when producing the Li ion conductive fine particles shown in FIG. 1, and FIG. 2 (B) FIG. 8 is a cross-sectional view taken along line 8B-8B shown in FIG.

The plasma apparatus has a cylindrical vacuum chamber 3. Both ends of the vacuum chamber 3 are closed by a chamber lid 20. A container 30 is disposed inside the vacuum chamber 3. The container 30 has a hexagonal barrel shape (hexagonal barrel shape) as shown in FIG. 2 (B). And, so that the inside of the container 30 as an object to be nitrided Li ₃ PO ₄ fine particles 1 (Li ₃ PO ₄ particles of powder) is housed. The container 30 also functions as an electrode and is connected to a plasma power source 31 or a ground potential, and both can be switched by a switch 32. The cross section shown in FIG. 2 (B) is a cross section substantially parallel to the direction of gravity. In the present embodiment, the hexagonal barrel-shaped container 30 is used. However, the present invention is not limited to this, and a polygonal barrel-shaped container other than a hexagon can also be used.

The container 30 is provided with a drive mechanism (not shown) for pendulum operation or rotation. Nitrogen plasma treatment is performed while stirring or rotating the Li ₃ PO ₄ fine particles 1 in the container 30 by pendulum operation or rotation of the container 30 as indicated by an arrow by this drive mechanism. A rotation axis when the container 30 is pendulum operated or rotated by the drive mechanism is an axis parallel to a substantially horizontal direction (a direction perpendicular to the gravity direction). Further, the airtightness in the vacuum chamber 3 is maintained even when the container 30 is rotated.

The plasma apparatus also includes a gas introduction mechanism that introduces gas into the vacuum chamber 3. The gas introduction mechanism has a cylindrical gas shower electrode 24, and the gas shower electrode 24 is disposed in the container 30. That is, an opening is formed on one side of the container 30, and the gas shower electrode 24 is inserted from this opening. The gas shower electrode 24 is formed with a plurality of gas outlets through which one or more gases are blown out in a shower shape. This gas outlet is disposed so as to face the Li ₃ PO ₄ fine particles 1 accommodated in the container. The gas outlet is arranged in a direction of about 1 ° to 90 ° in the rotation direction of the container 30 with respect to the direction of gravity.

  The gas shower electrode 24 is connected to a vacuum valve, a mass flow controller (MFC), a vacuum valve, a filter, and a gas introduction source (not shown). This gas introduction source is an introduction source of nitrogen gas or a gas containing nitrogen.

Further, the plasma apparatus includes a plasma power supply mechanism, and this plasma power supply mechanism has a plasma power source 25 connected to the gas shower electrode 24 via a switch 33. Each of the plasma power sources 25 and 31 is a high frequency power source that supplies a high frequency power (RF output) of 50 kHz or more and 500 kHz or less. An impedance matching unit (matching box) (not shown) is connected between the high frequency power source and the gas shower electrode 24. It is preferable to arrange in. That is, in this case, the gas shower electrode 24 is connected to a matching box, and the matching box is connected to a high frequency power source (RF power source) via a coaxial cable.
A plasma power source may be connected to one of the gas shower electrode 24 and the container 30 and a ground potential may be connected to the other, or a plasma power source may be connected to both the gas shower electrode 24 and the container 30. Also good.

  In addition, the plasma apparatus includes an evacuation mechanism that evacuates the inside of the vacuum chamber 3. For example, the gas shower electrode 24 is provided with an exhaust port (not shown) for exhausting the inside of the vacuum chamber 3, and the exhaust port is connected to a vacuum pump (not shown).

Next, a method for producing Li ion conductive fine particles or amorphous LiPON fine particles in which an amorphous LiPON layer is formed on the surface of Li ₃ PO ₄ fine particles using the plasma apparatus will be described.

First, crystalline Li ₃ PO ₄ fine particles 1 are prepared. The particle size of the Li ₃ PO ₄ fine particles is 0.01 μm or more and 1000 μm or less.

Next, the Li ₃ PO ₄ fine particles 1 are accommodated in the container 30. Then, the inside of the vacuum chamber 3 is exhausted to a predetermined pressure (for example, 6 Pa or less) by operating a vacuum pump. At the same time, the container 30 is swung or rotated by the drive mechanism, so that the Li ₃ PO ₄ fine particles 1 accommodated in the container 30 move while rolling between 90 ° in the gravity direction and the rotation direction on the inner surface of the container 30. .

Next, N ₂ gas is introduced into the mass flow controller in the gas introduction source, and the flow rate is controlled by the mass flow controller, and N ₂ gas having a flow rate of, for example, 10 to 20 sccm is introduced into the gas shower electrode 24. Then, N ₂ gas is blown out from the gas outlet of the gas shower electrode. As a result, gas is blown onto the Li ₃ PO ₄ fine particles 1 that are moving while rolling in the container 30, and a predetermined pressure is maintained by a balance between the controlled gas flow rate and the exhaust capacity.

Thereafter, an RF output of, for example, 380 kHz is supplied to the gas shower electrode 24 from, for example, a high frequency power supply (RF power supply) that is an example of the plasma power supply 25 via a matching box. At this time, the container 30 is connected to the ground potential. Thereby, plasma is ignited between the gas shower electrode 24 and the container 30. At this time, the matching box matches the impedance of the container 30 and the gas shower electrode 24 by the inductance L and the capacitance C. As a result, plasma is generated in the container 30, and the DC voltage component when forming the plasma is set to -500 V or less (preferably -900 to -1300 V), and the surface of the Li ₃ PO ₄ fine particles 1 is uniform. In addition, a powerful nitrogen plasma treatment is performed.

Thus, Li ion conductive fine particles in which an amorphous LiPON layer is formed on at least the surface of Li ₃ PO ₄ fine particles 1 (the N content of the LiPON layer is 2.0 wt% or more (preferably 3.5 wt% or more)), or Li Amorphous LiPON fine particles that are nitrided to the inside of ₃ PO ₄ fine particles 1 can be produced.

The reason why the N content of the LiPON layer can be 2.0% by weight or more (preferably 3.5% by weight or more) and the reason why the Li ₃ PO ₄ fine particles 1 can be nitrided will be described below.
This is because the surface of the Li ₃ PO ₄ fine particles 1 can be strongly subjected to nitrogen plasma treatment by applying a high DC bias with a DC voltage component at the time of plasma formation of −500 V or less. Therefore, a large amount of nitrogen can be introduced into the Li ₃ PO ₄ fine particles 1.

Further, since the Li ₃ PO ₄ fine particles 1 are rolled by the pendulum operation or rotation of the container 30, the entire surface of the Li ₃ PO ₄ fine particles 1 can be subjected to nitriding plasma treatment with good uniformity. Therefore, a large amount of nitrogen can be introduced homogeneously from the surface to the inside of the Li ₃ PO ₄ fine particles 1.

Further, in the present embodiment, N ₂ gas is blown out from the gas blowout port of the gas shower electrode. However, the present invention is not limited to this, and a gas containing N ₂ is blown out from the gas blowout port of the gas shower electrode. May be.

[Embodiment 3]
FIG. 3 is a cross-sectional view for explaining a method for producing Li ion conductive fine particles and amorphous LiPON fine particles having electronic conductivity according to one embodiment of the present invention.

Since the formation of the amorphous LiPON layer 12 on the surface of the Li ₃ PO ₄ fine particles 11 and the process of manufacturing the amorphous LiPON fine particles 14 are the same as those in the first embodiment, the description thereof is omitted.

After the amorphous LiPON layer 12 is formed on the surface of the Li ₃ PO ₄ fine particles 11 or the amorphous LiPON fine particles 14 are produced, the metal particles 15 (or the metal film 17) are partially formed on the surfaces. Thereby, the surface LiPON layer 12 and the surface of the amorphous LiPON fine particles 14 are exposed from the metal particles 15 (or the metal film 17).

  As the metal particles 15 or the metal film 17, various materials can be used as long as they function as a conductive auxiliary agent for conducting electrons. For example, Pt, Au, Al, Cu, Ti, Ag, Fe, Co, Mn , W or the like. The reason why the surface LiPON layer 12 is exposed from the metal particles 15 (or the metal film 17) is that if the surface LiPON layer 12 and the amorphous LiPON fine particles 14 are all covered with metal particles, Li ions cannot be conducted. is there.

  In the present embodiment, in addition to the effects of the first embodiment, electron conductivity can be imparted.

  Next, a method for partially forming the metal particles 15 (or the metal film 17) on the surface LiPON layer 12 and the amorphous LiPON fine particles 14 will be described.

In the plasma apparatus shown in FIG. 2, the gas shower electrode 24 is changed to a sputtering target made of the same metal as the metal particles 15 or the metal film 17, and a gas introduction mechanism for introducing Ar gas is added. A container 30 of this apparatus accommodates Li ion conductive fine particles 13 and amorphous LiPON fine particles 14 in which an amorphous LiPON layer 12 is formed on the surface of Li ₃ PO ₄ fine particles 11. Next, Ar gas is introduced into the container 30 by the gas introduction mechanism, the inside of the container 30 is evacuated by the evacuation mechanism, the container 30 is grounded, and power is supplied to the sputtering target by the plasma power source 25 to A plasma is formed on the container 30, and the container 30 is moved or rotated by a driving mechanism. Thus, the metal particles 15 or the metal film 17 is formed on a part of the surface of the fine particles while stirring or rotating the Li ion conductive fine particles 13 or the amorphous LiPON fine particles 14 in the container 30.

[Embodiment 4]
FIG. 4 is a cross-sectional view illustrating a lithium ion secondary battery according to one embodiment of the present invention.

The lithium ion secondary battery includes a first electrode layer 22, a second electrode layer 23, and an electrolyte layer 21, and the electrolyte layer 21 is between the first electrode layer 22 and the second electrode layer 23. Is arranged. The first electrode layer 22 is an electrode having a lithium metal oxide (for example, LiCoO ₂ ), and the second electrode layer 23 is an electrode having a carbon material (for example, amorphous carbon).

  The electrolyte layer 21 is formed by mixing and solidifying the Li ion conductive fine particles or amorphous LiPON fine particles described in any of Embodiments 1 and 2 and a binder (for example, polyvinylidene fluoride, styrene butadiene latex + carboxymethyl cellulose, etc.). It is a thing.

  Electrode layers 22 and 23 are partially formed from the Li ion conductive fine particles or amorphous LiPON fine particles described in any of Embodiments 1 and 2, or the metal particles (or metal film) described in any of Embodiment 3. Modified Li ion conductive fine particles or amorphous LiPON fine particles and a conductive auxiliary agent (for example, carbon auxiliary agent) through which electrons are conducted are mixed and hardened (a binder may be included).

Next, the manufacturing method of a lithium ion secondary battery is demonstrated.
The Li ion conductive fine particles and amorphous LiPON fine particles of Embodiments 1 and 2 are mixed with a binder. Thereby, a paste-like electrolyte material can be produced.

  Next, this paste-like electrolyte material is placed between the first electrode 22 and the second electrode 23 and heated to solidify, whereby an all-solid lithium ion secondary battery can be produced.

According to the present embodiment, the solid electrolyte layer 21 is formed between the first electrode layer 22 and the second electrode layer 23, and the electrolyte layer 21 has Li ion conductive fine particles or amorphous LiPON fine particles. Therefore, it is possible to construct a good Li ion conductive path.
In addition, since the LiPON layer and LiPON fine particles on the surface of the Li ion conductive fine particles are amorphous, they are softer than the crystallized LiPON layer. Therefore, good interparticle contact between Li ion conductive fine particles can be realized. As a result, Li ion conductivity can be increased.

  If the Li ion conductive fine particles and the amorphous LiPON fine particles according to Embodiments 1 and 2 are added to the electrode layer, a good ion conduction path can be established in the electrode layer, and the ion conductivity can be increased.

In addition, when Li ion conductive fine particles or amorphous LiPON fine particles imparted with electron conductivity according to Embodiment 3 are used, metal particles are formed on the surface of Li ion conductive fine particles 13 or amorphous LiPON fine particles 14 as shown in FIG. 15 (or metal film 17) is formed. The metal particles 15 and the metal film 17 function as a conductive aid that conducts electrons. Therefore, if any of these particulate materials 16, 18, 19, and 20a is added to the electrode layers 22 and 23, in addition to ionic conductivity, electron conductivity can be imparted. The content can be reduced. Therefore, the content of the electrode material such as LiCoO ₂ or amorphous carbon can be relatively increased, and as a result, a lithium ion secondary battery with higher charge / discharge capacity can be realized.

<Preparation of sample>
Samples were prepared using Li ₃ PO ₄ fine particle material manufactured by Toshima Seisakusho, with an average particle size of 29 μm for physical property evaluation and 77 nm for ion conductivity evaluation. These Li ₃ PO ₄ fine particles (0.5 g) were introduced into a hexagonal barrel (corresponding to the container shown in Fig. 2) with an inner diameter of 200 mm and a width of 29 mm. Attached to. After evacuating slowly to 1 × 10 ⁻³ Pa with a rotary pump and an oil diffusion pump, N ₂ gas was introduced. Subsequently, N ₂ plasma treatment was performed for 5 to 180 minutes under the conditions of high frequency output: 100 W, N ₂ gas pressure: 10 Pa, and no heating. At this time, while giving mechanical vibration to the barrel, a pendulum was operated by a motor at a speed of 5 rpm and an angle of ± 75 °. After the treatment, N ₂ gas was slowly introduced into the chamber and returned to atmospheric pressure, and then the sample was taken out. The obtained sample was stored in an Ar atmosphere using a glove box (1ADB-3KP-TS, Miwa Seisakusho).

<Evaluation of prepared sample>
The chemical bonding state of the sample surface was evaluated by photoelectron spectroscopy (XPS: ESCALAB 250X, Thermo Fisher Scientific). In this measurement, Al Kα monochromatic at 25 W was excited, and the obtained spectrum was normalized with the C1s peak (285 eV).

      The cross section of the sample was observed using a transmission electron microscope (TEM; JEM-2100, JEOL). A sample for TEM observation was prepared as follows. A sample attached to a Ni plate using carbon tape was coated with Pt (JEOL; JSM-7000F), and after carbon ink was dropped and dried, Pt was coated again to form a surface protective layer. Subsequently, a 3 × 13 × 7 mm piece was taken out with a focused ion beam (FIB: FB-2100, Hitachi High-Tech), fixed on a molybdenum grid for TEM observation, and the thickness of the center of this piece was 100 nm. I sharpened it to the extent.

<Electrochemical measurement>
The ionic conductivity (25 ° C.) of the prepared sample was determined from a Cole-Cole plot (measurement frequency range: 5 Hz to 1 MHz) measured using a chemical impedance apparatus (3582-30, Hioki Electric). The measurement was carried out by putting a sample sandwiched between brass plates (diameter: 15 mm) as a current collector into an electrochemical cell purchased from Mick Lab and Chemix, and compressing it at 0.2 to 1 MPa using a press machine. . After the measurement, the thickness of the sample was also estimated using a digital micrometer (MDE-25MJ, Mitutoyo). From the obtained results, the ionic conductivity (δ, S cm ⁻¹ ) was determined from the following equation (1).
δ = l / AR (1)
Here, l and A are the thickness (cm) of the sample and the measurement area (2.01 cm ² ), and R represents the resistance value (Ω) obtained from the fitting curve of the Cole-Cole plot.

<Results and discussion>
1. A photograph of Li ₃ PO ₄ microparticles N ₂ plasma treatment with N ₂ Li ₃ was treated with the plasma PO ₄ fine characterization various times shown in FIG. White Li ₃ PO ₄ microparticles turned light gray after 60 minutes of plasma treatment. This hue became darker with increasing treatment time and turned brown after 180 minutes treatment.

In order to clarify the cause of this hue change, XPS measurement was performed. FIG. 6 (I) shows XPS survey spectra of (A) untreated and (B) treated sample (treatment time: 90 minutes). The peak obtained in any sample can be attributed to signals derived from Li, P, and O elements contained in the measurement atmosphere or C1s derived from the carbon tape used for measurement and Li ₃ PO ₄ . However, a minute peak that can be attributed to N1s was observed around 398 eV in the treated sample. The narrow scan spectrum of the N1s peak of the treated sample is shown in Fig. 6 (II). The spectrum showed one broad peak, which was separated into two peaks with peak tops at 398.1 and 399.2 eV. These separation peaks were attributed to -N = and -N <bonds, and it was found that LiPON was produced by N ₂ plasma treatment.

The formation state of LiPON was evaluated by TEM observation. FIG. 7 shows a cross-sectional TEM image and an electron beam diffraction image of a sample treated with (A) untreated and (B) treated for 90 minutes. In the case of the untreated sample, the sample cross section was uniform, and spots due to the Li ₃ PO ₄ structure were observed in the electron beam diffraction image. On the other hand, in the cross-sectional TEM image of the treated sample, an altered layer having a uniform thickness of about 600 nm was observed on the surface of the fine particles. The electron diffraction pattern of the lower layer matches that of the untreated sample and can be regarded as a Li ₃ PO ₄ layer, whereas a halo appears in the electron diffraction pattern of the altered layer, indicating that the altered layer is amorphous. Clarifies that it is a LiPON layer.

      The relationship between LiPON layer thickness and processing time is shown in FIG. In the treatment time of 0 to 90 minutes, the thickness of the LiPON layer increased linearly, and then the film thickness gradually increased.

2. Ionic conductivity evaluation of Li ₃ PO ₄ fine particles treated with N ₂ plasma
The ionic conductivity of the N ₂ plasma treated sample was evaluated from the impedance measurement results. FIG. 9 shows Cole-Cole plots and fitting curves thereof of (A) untreated and (B) treated samples (treatment conditions: 100 W, 60 minutes) measured by changing the press pressure. In the case of the untreated sample, a semicircular arc plot appeared at any press pressure. The size of the semicircular arc decreased as the press pressure increased from 0.4 MPa to 0.8 and 1 MPa. Similar results were obtained with the treated sample, but the size of the semicircular arc was 1/10 or less of the untreated sample.

FIG. 10 shows the relationship between the ionic conductivity (δ) obtained from the fitting curve of the Cole-Cole plot and the press pressure (untreated: ●, sample treated in 60 minutes: ○). In the treated sample, the ionic conductivity increased with the pressing pressure and became almost constant at 0.8 MPa or more. A similar tendency is observed in the untreated sample, but the ionic conductivity change with respect to the press pressure is smaller than that in the treated sample. In addition, the ionic conductivity (1.33 × 10 ^-6 S cm ^-2 ) of the treated sample obtained at a press pressure of 1 MPa is about 100 times higher than that of the untreated sample (2.76 × 10 ^-8 S cm ^-2 ). The value of a typical LiPON thin film (2.6 to 6.4 × 10 ⁻⁶ S cm ⁻¹ , Non-Patent Documents 2 and 3) was comparable.

The influence of N ₂ plasma treatment time on ion conductivity was also evaluated by impedance measurement. FIG. 11 shows a Cole-Cole plot of samples treated for 60, 90, and 120 minutes. As shown in the inset, when the processing time was increased from 60 minutes to 90 minutes, the size of the semicircular arc decreased. However, the size of the semicircular arc in the 120 minute treated sample was dramatically larger than that in the 90 minute treated sample.

FIG. 12 shows the relationship between plasma processing time and ion conductivity. The ionic conductivity increases exponentially with increasing processing time, and the ionic conductivity of 90 minutes (1.75 × 10 ^-5 ± 1.25 × 10 ^-5 S cm ^-1 ) is described in Non-Patent Documents 2 and 3. 2-5 times higher than reported values for LiPON thin films (2.6-6.4 × 10 ^-6 S cm ^-1 ). However, the ionic conductivity decreased rapidly when the treatment time was longer than 90 minutes.

Fig. 13 shows a TEM image of a Cu-sputtered N ₂ plasma-treated sample (treatment time: 90 minutes) (sputtering conditions: high-frequency output: 50 W, sputtering time: 90 minutes, Ar gas pressure: 5 Pa, barrel operation : Pendulum (± 75 °, 3.5 rpm)). Although several nanometers of Cu nanoparticles (black dots) are uniformly modified on the surface of the plasma-treated sample, a part of the surface of the fine particles composed of the LiPON layer is exposed.

<Conclusion>
In this example, LiPON fine particles that contribute to the construction of a lithium ion conduction path in a bulk-type all-solid-state lithium ion secondary battery were prepared using a multi-barrel plasma surface modification method. As a result, it was found that Li ₃ PO ₄ fine particles having a LiPON layer on the surface could be prepared by this method, and that the ion conductivity was higher than that of the LiPON thin film. Note that by performing a sputtering operation after the N ₂ plasma treatment, a metal such as Cu can be uniformly modified on the surface of the fine particles with the surface LiPON layer exposed.

1 Li ₃ PO ₄ Fine Particle 3 Vacuum Chamber 11 Li ₃ PO ₄ Fine Particle 12 Amorphous LIPON Layer 13 Li Ion Conductive Fine Particle 14 Amorphous LiPON Fine Particle 15 Metal Particle 16 Fine Particle 17 Metal Film 18 Fine Particle 19 Fine Particle 20a Fine Particle 20 Chamber Lid 21 Electrolyte Layer 22 First electrode layer 23 Second electrode layer 24 Gas shower electrode 25 Plasma power source 30 Container 31 Plasma power source 32, 33 Switch

Claims (36)

Li ₃ PO ₄ fine particles,
An amorphous LiPON layer formed on at least the surface of the Li ₃ PO ₄ fine particles;
Li ion conductive fine particles characterized by comprising: Amorphous LiPON fine particles produced by nitriding Li ₃ PO ₄ fine particles to the inside. In claim 1,
Li ion conductive fine particles, wherein the diameter of the Li ion conductive fine particles is 0.01 μm or more and 1000 μm or less. In claim 2,
Amorphous LiPON fine particles having a diameter of 0.01 μm or more and 1000 μm or less. In claim 1 or 3,
Having metal particles or metal film formed on the LiPON layer;
Li ion conductive fine particles, wherein the LiPON layer is exposed from the metal particles or the metal film. In claim 2 or 4,
Having metal particles or metal film formed on the surface of the amorphous LiPON fine particles,
The amorphous LiPON fine particles, wherein the surface of the amorphous LiPON fine particles is exposed from the metal particles or the metal film. The Li ion conductive fine particles according to claim 1 or 3, wherein Li ₃ PO ₄ fine particles are accommodated in a container, an electrode facing the inner surface of the container is disposed, and nitrogen gas or a gas containing nitrogen is contained in the container. , Evacuating the container, supplying power between the electrode and the container to form plasma in the container, and pendulating or rotating the container, the Li ₃ PO ₄ while fine particles are stirred or rotated, the Li ₃ PO ₄ Li ion conductivity particles, characterized in that it is produced by forming a LiPON layer of amorphous to the microparticle surface. The amorphous LiPON fine particles according to claim 2 or 4, wherein the Li ₃ PO ₄ fine particles are accommodated in a container, an electrode facing the inner surface of the container is arranged, and nitrogen gas or a gas containing nitrogen is introduced into the container Then, the inside of the container is evacuated, electric power is supplied between the electrode and the container to form plasma in the container, and the Lid in the container is moved by pendulum operation or rotation. ₃ PO ₄ while fine particles are stirred or rotated, the Li ₃ PO ₄ amorphous LiPON fine particles, characterized in that the fine particles to the inside is produced by nitriding. The Li ion conductive fine particles according to claim 1 or 3,
A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Which is manufactured using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. Li ion conductive fine particles characterized by controlling to form an amorphous LIPON layer on the surface of the Li ₃ PO ₄ fine particles while rotating. The amorphous LiPON fine particles according to claim 2 or 4,
A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Which is manufactured using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. Amorphous LiPON fine particles, wherein the Li ₃ PO ₄ fine particles are controlled to be nitrided to the inside while rotating. In claim 9,
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
Li ion conductive fine particles, wherein a DC voltage component in forming the plasma is −500 V or less. In claim 10,
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
Amorphous LiPON fine particles, wherein a DC voltage component in forming the plasma is −500 V or less.   An electrolyte layer, wherein the Li ion conductive fine particles according to any one of claims 1, 3, 7, 9, and 11 and a binder are mixed and hardened.   An electrolyte layer, wherein the amorphous LiPON fine particles according to any one of claims 2, 4, 8, 10, and 12 and a binder are mixed and hardened. A first electrode layer;
A second electrode layer;
An electrolyte layer disposed between the first electrode and the second electrode;
Comprising
The electrolyte layer is obtained by mixing Li ion conductive fine particles according to any one of claims 1, 3, 7, 9, and 11 and a binder, and solidifying them. Next battery. A first electrode layer;
A second electrode layer;
An electrolyte layer disposed between the first electrode and the second electrode;
Comprising
The lithium ion secondary battery, wherein the electrolyte layer is obtained by mixing and solidifying the amorphous LiPON fine particles according to any one of claims 2, 4, 8, 10, and 12 and a binder. .   A method for producing an electrode layer, comprising mixing and solidifying the Li ion conductive fine particles according to any one of claims 1, 3, 7, 9, and 11 and a conductive auxiliary agent through which electrons are conducted.   A method for producing an electrode layer, comprising mixing and solidifying the amorphous LiPON fine particles according to any one of claims 2, 4, 8, 10, and 12 and a conductive auxiliary agent through which electrons are conducted. In claim 17 or 18,
The method for producing an electrode layer, wherein the electrode layer contains a binder. In a method for manufacturing a lithium ion secondary battery having a first electrode layer and a second electrode layer,
The first electrode layer is manufactured by the electrode layer manufacturing method according to any one of claims 17 to 19,
A method for manufacturing a lithium ion secondary battery, wherein the second electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 17 to 19. A method for producing Li ion conductive fine particles, characterized in that an amorphous LIPON layer is formed on at least the surface of the Li ₃ PO ₄ fine particles by treating the Li ₃ PO ₄ fine particles with nitrogen plasma. A method for producing amorphous LiPON fine particles, characterized by treating Li ₃ PO ₄ fine particles with nitrogen plasma and nitriding the Li ₃ PO ₄ fine particles to the inside. In claim 21,
Li ion conductive fine particles, wherein the diameter of the Li ion conductive fine particles is 0.01 μm or more and 1000 μm or less. In claim 22,
Amorphous LiPON fine particles having a diameter of 0.01 μm or more and 1000 μm or less. Storing Li ₃ PO ₄ fine particles in a container;
Disposing an electrode facing the inner surface of the container;
Introducing nitrogen gas or nitrogen-containing gas into the container;
Evacuating the container; and
An amorphous LiPON layer is formed on the surface of the Li ₃ PO ₄ fine particles in the container by supplying electric power between the electrode and the container to form a plasma in the container, and the pendulum operation or rotation of the container. Forming a step;
A method for producing Li ion conductive fine particles, comprising: Storing Li ₃ PO ₄ fine particles in a container;
Disposing an electrode facing the inner surface of the container;
Introducing nitrogen gas or nitrogen-containing gas into the container;
Evacuating the container; and
By supplying electric power between the electrode and the container to form plasma in the container, the Li ₃ PO ₄ fine particles in the container are nitrided to the inside by operating the pendulum or rotating the container. Forming amorphous LiPON fine particles with
A process for producing amorphous LiPON fine particles characterized by comprising: A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Is a method for producing Li ion conductive fine particles using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. A method for producing Li ion conductive fine particles, characterized by controlling the formation of an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles while rotating. A container,
A drive mechanism for pendulum operation or rotation of the container;
An electrode disposed in the container;
A power source for supplying power between the electrode and the container;
A gas introduction mechanism for introducing nitrogen gas or a gas containing nitrogen into the container;
An exhaust mechanism for evacuating the inside of the container;
A control unit;
Is a method for producing amorphous LiPON fine particles using a plasma apparatus comprising:
The control unit introduces nitrogen gas or nitrogen-containing gas by the gas introduction mechanism into the container in which Li ₃ PO ₄ fine particles are accommodated, evacuates the container by the exhaust mechanism, and the power by the power source Electric power is supplied between the electrode and the container to form plasma in the container, and the container is stirred or rotated by the drive mechanism, thereby stirring or rotating the Li ₃ PO ₄ fine particles in the container. A method for producing amorphous LiPON fine particles, characterized in that the Li ₃ PO ₄ fine particles are controlled to be nitrided to the inside while rotating. In claim 27,
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
A method for producing Li ion conductive fine particles, wherein a DC voltage component in forming the plasma is −500 V or less. In claim 28,
The power source is a high frequency power source having a frequency of 50 kHz to 500 kHz,
A method for producing amorphous LiPON fine particles, wherein a DC voltage component in forming the plasma is −500 V or less. In claim 27 or 29,
After forming an amorphous LiPON layer on the surface of the Li ₃ PO ₄ fine particles, forming metal particles or a metal film on the LiPON layer,
The LiPON layer is exposed from the metal particles or the metal film, and the method for producing Li ion conductive fine particles. In claim 28 or 30,
After forming the amorphous LiPON fine particles by nitriding the Li ₃ PO ₄ fine particles to the inside, forming metal particles or a metal film on the amorphous LiPON fine particles,
A method for producing amorphous LiPON fine particles, wherein the surface of the amorphous LiPON fine particles is exposed from the metal particles or the metal film.   An electrode layer characterized by mixing and solidifying Li ion conductive fine particles produced by the production method according to any one of claims 25, 27, 29, and 31, and a conductive additive that conducts electrons. Manufacturing method.   An amorphous LiPON fine particle produced by the production method according to any one of claims 26, 28, 30 and 32, and a conductive additive capable of conducting electrons are mixed and hardened to produce an electrode layer. Method. In claim 33 or 34,
The method for producing an electrode layer, wherein the electrode layer contains a binder. In a method for manufacturing a lithium ion secondary battery having a first electrode layer and a second electrode layer,
The first electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 33 to 35,
36. A method of manufacturing a lithium ion secondary battery, wherein the second electrode layer is manufactured by the method for manufacturing an electrode layer according to any one of claims 33 to 35.