阅读说明：本技术 粉体涂覆装置、能量设备的制造方法、电池用正极及负极 (Powder coating device, method for manufacturing energy device, and positive electrode and negative electrode for battery ) 是由 小岛俊之 大河内基裕 松野俊一 堀川晃宏 于 2021-04-20 设计创作，主要内容包括：本公开提供一种粉体涂覆装置、能量设备的制造方法、电池用正极及负极。粉体涂覆装置具备搬运装置(9)、粉体供给部(11)和刮板(2)。搬运装置(9)使片材(4)沿着给定方向移动。粉体供给部(11)向片材(4)的表面(4a)上供给粉体。刮板(2)配置为在与片材(4)之间形成间隙,对由粉体供给部(11)供给到片材(4)的表面(4a)上的粉体(3)的厚度进行调整。刮板以2kHz以上且300kHz以下的频率振动。(The present disclosure provides a powder coating device, a method for manufacturing an energy device, a positive electrode and a negative electrode for a battery. The powder coating device is provided with a conveying device (9), a powder supply part (11) and a scraper (2). The conveying device (9) moves the sheet (4) in a predetermined direction. A powder supply unit (11) supplies powder onto the surface (4a) of the sheet (4). The scraper (2) is arranged to form a gap with the sheet (4) and to adjust the thickness of the powder (3) supplied onto the surface (4a) of the sheet (4) by the powder supply unit (11). The blade vibrates at a frequency of 2kHz to 300 kHz.)

1. A powder coating device is provided with:

a driving section that moves the member in a given direction;

a powder supply unit configured to supply powder onto a surface of the member;

a scraper configured to form a gap with the member and adjust a thickness of the powder supplied from the powder supply unit onto the surface of the member,

the blade vibrates at a frequency of 2kHz to 300 kHz.

2. The powder coating apparatus according to claim 1,

the average particle diameter D50 of the powder is 0.005-50 μm.

3. The powder coating apparatus according to claim 1 or 2,

an angle formed by a main surface of the scraper contacting the powder with respect to a perpendicular direction of the surface of the member is greater than 0 °.

4. The powder coating apparatus according to claim 3,

the angle is above the rest angle of the powder.

5. The powder coating apparatus according to claim 1 or 2,

the blade is formed in a cylindrical shape having an axis parallel to the surface of the member and orthogonal to a moving direction of the surface of the member.

6. The powder coating apparatus according to any one of claims 1 to 5,

the squeegee vibrates in a horizontal direction parallel to a main surface of the squeegee and a vertical direction perpendicular to the main surface of the squeegee,

the magnitude of the vibration in the horizontal direction is larger than the magnitude of the vibration in the vertical direction.

7. The powder coating apparatus according to any one of claims 1 to 6,

the ratio of the thickness of the powder before the thickness adjustment by the scraper to the thickness of the powder after the thickness adjustment by the scraper is within the range of 1: 1 to 3: 1.

8. The powder coating apparatus according to any one of claims 1 to 7,

further provided with: and a pressing section for compressing the powder on the member whose thickness is adjusted by the scraper.

9. A method of manufacturing an energy device, comprising:

supplying powder onto a surface of a member while moving the member in a predetermined direction; and

the thickness of the powder supplied onto the surface is adjusted using a scraper,

the blade is configured to form a gap with the member,

the blade vibrates at a frequency of 2kHz to 300 kHz.

10. A positive electrode for a battery, comprising:

a positive electrode current collector; and

a positive electrode layer containing a positive electrode active material and formed on the positive electrode current collector,

the concentration of the solvent contained in the positive electrode layer is 50ppm or less,

the area of the positive electrode layer is 900mm²In the above-mentioned manner,

the thickness of the positive electrode layer is 15 [ mu ] m or more,

the variation in the thickness of the positive electrode layer is ± 5% or less.

11. The positive electrode for a battery according to claim 10,

the positive electrode layer is provided with a positive electrode mixture layer containing the positive electrode active material and a solid electrolyte having ion conductivity, and formed on the positive electrode current collector,

the concentration of the solvent contained in the positive electrode mixture layer is 50ppm or less,

the area of the positive electrode mixture layer is 900mm²In the above-mentioned manner,

the thickness of the positive electrode mixture layer is 15 [ mu ] m or more,

the thickness variation of the positive electrode mixture layer is + -5% or less.

12. The positive electrode for a battery according to claim 11,

cross-sectional area of 100 μm²The total area of the aggregated portions of the solid electrolyte in the positive electrode mixture layer is 2% or less with respect to the cross-sectional area of the positive electrode mixture layer.

13. A negative electrode for a battery includes:

a negative electrode current collector; and

a negative electrode layer containing a negative electrode active material and formed on the negative electrode current collector,

the concentration of the solvent contained in the negative electrode layer is 50ppm or less,

the area of the negative electrode layer is 900mm²In the above-mentioned manner,

the thickness of the negative electrode layer is more than 15 μm,

the variation in the thickness of the negative electrode layer is ± 10% or less.

14. The negative electrode for a battery according to claim 13,

the negative electrode layer is provided with a negative electrode mixture layer containing the negative electrode active material and a solid electrolyte having ion conductivity, and formed on the negative electrode current collector,

the concentration of the solvent contained in the negative electrode mixture layer is 50ppm or less,

the area of the negative electrode mixture layer is 900mm²In the above-mentioned manner,

the thickness of the negative electrode mixture layer is more than 15 μm,

the thickness of the negative electrode mixture layer varies by + -10% or less.

Technical Field

The present disclosure relates to a powder coating device, a method for manufacturing an energy device, a positive electrode for a battery, and a negative electrode for a battery.

Background

Conventionally, a technique of conveying a member such as a metal foil and coating a powder on the surface of the member has been known.

For example, patent document 1 discloses a technique of coating a composite material (powder) containing an active material on the surface of a current collector, which is a long metal foil.

Patent document 1 describes that after the powder is supplied onto the surface of the metal foil, the powder is flattened by a blade, thereby adjusting the thickness of the powder to a uniform thickness. In addition, in patent document 1, the flowability of the powder is improved by performing the granulation step of the powder.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2014-198293

Disclosure of Invention

A powder coating device according to an embodiment of the present disclosure includes: a driving section that moves the member in a given direction; a powder supply unit configured to supply powder onto a surface of the member; and a scraper configured to form a gap with the member and to adjust a thickness of the powder supplied from the powder supply unit onto the surface of the member. The blade vibrates at a frequency of 2kHz to 300 kHz.

A method for manufacturing an energy device according to an embodiment of the present disclosure includes: supplying powder onto a surface of a member while moving the member in a predetermined direction; the thickness of the powder supplied onto the surface is adjusted using a scraper. The blade is configured to form a gap with the member. The blade vibrates at a frequency of 2kHz to 300 kHz.

A positive electrode for a battery according to an embodiment of the present disclosure includes: a positive electrode current collector; and a positive electrode layer containing a positive electrode active material and formed on the positive electrode current collector, wherein the concentration of a solvent contained in the positive electrode layer is 50ppm or less, and the area of the positive electrode layer is 900mm²Above, what is needed isThe thickness of the positive electrode layer is 15 [ mu ] m or more, and the variation in the thickness of the positive electrode layer is ± 5% or less.

A negative electrode for a battery according to an embodiment of the present disclosure includes: a negative electrode current collector; a negative electrode layer containing a negative electrode active material and formed on the negative electrode current collector, the negative electrode layer containing a solvent at a concentration of 50ppm or less, the negative electrode layer having an area of 900mm²The negative electrode layer has a thickness of 15 μm or more, and the variation in the thickness of the negative electrode layer is ± 10% or less.

Drawings

Fig. 1 is a schematic view showing a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 2 is a schematic view showing a part of a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 3A is a schematic view showing a part of a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 3B is a schematic view showing a part of a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 3C is a schematic view showing a part of a powder coating apparatus according to another embodiment of the present disclosure.

Fig. 3D is a schematic view illustrating a part of a powder coating apparatus according to another embodiment of the present disclosure.

Fig. 3E is a schematic view showing a part of a powder coating apparatus according to still another embodiment of the present disclosure.

Fig. 3F is a schematic view showing a part of a powder coating apparatus according to still another embodiment of the present disclosure.

Fig. 4 is a schematic view showing a part of a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 5 is a schematic view showing a part of a powder coating apparatus according to an embodiment of the present disclosure.

Fig. 6 is a diagram illustrating a manufacturing process of an energy device according to an embodiment of the present disclosure.

Fig. 7 is a cross-sectional view of a positive electrode of an all-solid battery according to an embodiment of the present disclosure.

Fig. 8 is a cross-sectional view of the negative electrode of the all-solid battery according to one embodiment of the present disclosure.

Fig. 9 is a schematic view showing a part of a conventional powder coating apparatus.

Fig. 10 shows the comparison result of the thickness variation of the powder after passing through the squeegee.

Fig. 11 shows the analysis result of the retained particle ratio.

Description of the symbols

1: a powder coating device;

2. 22a, 22b, 22c, 102, 103: a squeegee;

2a, 2c, 22a1, 22b1, 22c1, 102a, 103 a: a main face;

2 b: an end face;

3: powder;

4: a sheet (member);

4 a: a surface;

5: compressing the powder layer;

6: a roll press (press section);

9: a conveying device (drive unit);

11: a powder supply unit;

12: an ultrahigh frequency vibration generator;

51: a positive electrode active material;

52: a solid electrolyte;

53: a positive electrode mix layer;

54: a positive electrode current collector;

61: a negative electrode active material;

63: a negative electrode mix layer;

64: a negative electrode current collector;

a: a resting angle;

θ: and (4) an angle.

Detailed Description

As shown in fig. 9, since the powder receives a force in the direction opposite to the moving direction (the metal foil conveying direction) when it contacts the blade, when the powder has low fluidity, the powder tends to stay on the upstream side of the blade in the metal foil conveying direction, that is, a bridge tends to be generated between the blade and the metal foil. In patent document 1, vibration having a frequency of about 700Hz is applied to the blade in order to suppress the retention of powder. In addition, the hollow arrows in fig. 9 show the conveying direction of the plate material.

However, even if the blade is vibrated at a frequency of about 700Hz as in patent document 1, the retention of powder having low fluidity cannot be sufficiently suppressed. Further, even when the fluidity of the powder is high, it is difficult to flatten the powder so that the thickness of the powder supplied onto the surface of the member becomes uniform with high accuracy.

An object of the present disclosure is to provide a powder coating apparatus capable of forming a powder layer with less variation in film thickness on the surface of a member, a method for manufacturing an energy device, a positive electrode for a battery, and a negative electrode for a battery.

The disclosed powder coating device is provided with: a driving section that moves the member in a given direction; a powder supply unit configured to supply powder onto a surface of the member; and a scraper configured to form a gap with the member and adjust the thickness of the powder supplied to the surface of the member by the powder supply unit. In the powder coating device, the blade vibrates at a frequency of 2kHz to 300 kHz.

According to the present disclosure, a powder layer with less variation in film thickness can be formed on the surface of a member.

In the powder coating apparatus of the present disclosure, the powder is continuously supplied onto the surface of the member using the powder supply unit while the member is moved by the drive unit. At this time, the powder supplied onto the surface of the member passes through the gap between the scraper and the surface of the member, whereby the thickness of the powder supplied onto the surface of the member is adjusted to be substantially the same as the width of the gap. In this case, the powder is pressed by the contact with the scraper, and the powder is accumulated and aggregated between the scraper and the member, so that powder clogging is likely to occur. However, in the powder coating apparatus of the present disclosure, since the scraper vibrates at a frequency of 2kHz to 300kHz, the flowability of the powder can be improved, and the powder is less likely to accumulate and aggregate, and clogging of the powder can be suppressed.

The embodiments described below are all illustrative or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions and connection modes of the constituent elements, steps, order of the steps, and the like shown in the following embodiments are examples, and the present disclosure is not limited thereto. Note that, among the components in the following embodiments, components that are not described in independent claims will be described as arbitrary components.

The drawings are schematic and not necessarily strictly shown. In the drawings, the same structural members are denoted by the same reference numerals. In the following embodiments, expressions such as substantially parallel are used. For example, substantially parallel means not only completely parallel, but also substantially parallel, i.e. for example including an error of the order of a few percent. Further, substantially parallel means parallel within a range where the effect based on the present disclosure can be achieved. The same applies to other expressions using "approximately".

Hereinafter, the embodiments will be described with reference to the drawings as appropriate. However, detailed description of the process that is more than necessary may be omitted. For example, detailed descriptions of already known matters and repetitive descriptions of substantially the same configuration may be omitted. This is to avoid the following description from unnecessarily becoming redundant to make it readily understandable by those skilled in the art.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

(embodiment mode)

A powder coating apparatus 1, which is an embodiment of the powder coating apparatus according to the present disclosure, will be described below with reference to fig. 1 to 2.

The powder coating apparatus 1 is an apparatus that coats the powder 3 on the surface 4a of the sheet 4 while conveying a sheet-like member (hereinafter, also referred to as the sheet 4) by a conveying apparatus 9 as a driving unit. In detail, the powder coating apparatus 1 is an apparatus as follows: while the sheet 4 is conveyed by the conveying device 9, the powder 3 is continuously supplied onto the surface of the sheet 4 by using the powder supply portion 11, and the sheet 4 and the powder 3 on the sheet 4 are continuously compressed by the roll press 6, thereby forming the compressed powder layer 5 on the surface of the sheet 4.

The conveying device 9 is a driving unit that moves the sheet 4 in a predetermined direction, and is not particularly limited as long as the sheet 4 can be conveyed. In the present embodiment, the conveying device 9 continuously draws out the sheet 4 wound in a roll shape, but the present invention is not limited thereto, and the conveying device 9 may intermittently draw out the sheet 4. The conveying device 9 is an example of a driving unit. When the rolled sheet 4 is continuously conveyed as in the present embodiment, the sheet 4 having the compressed powder layer 5 formed on the surface 4a may be wound into a roll shape again and collected. Further, a guide roller that rotates in accordance with the movement of the sheet 4, a control device that corrects the meandering of the sheet 4, and the like may be provided in the conveyance path of the sheet 4.

In the present embodiment, the sheet 4 is a long thin sheet and is wound, but the member is not limited to such a sheet 4. After the sheet 4 of a desired shape is pulled out from the conveying device 9 and the application of the powder 3 is completed, a new sheet 4 may be pulled out from the conveying device 9. The sheet 4 may not be wound into a roll shape. The member is not limited to the sheet 4, and may be any shape as long as it can coat the powder 3 using the powder coating apparatus 1. In the present embodiment, the sheet 4 is a current collector including a metal foil, but the material is not particularly limited, and any material may be used as long as it can coat the powder 3 using the powder coating apparatus 1.

The powder 3 may be a powdery material, and the raw material, the component, and the particle shape are not particularly limited. In the present embodiment, the powder 3 is a particle group containing an active material.

The average particle diameter (D50) of the powder 3 is preferably 0.005 μm to 50 μm. In this case, although the fluidity of the powder 3 is likely to decrease, the powder 3 can be inhibited from staying and agglomerating by the vibration of the blade 2, and therefore the compressed powder layer 5 with less variation in thickness can be formed on the surface 4a of the sheet 4. The average particle diameter (D50) is a volume-based median diameter calculated from the measurement value of the particle size distribution by the laser diffraction/scattering method, and can be measured using a commercially available laser analysis/scattering particle size distribution measuring apparatus.

The powder 3 may contain only 1 type of powder, or may contain 2 or more types of powder. When the powder 3 is an admixture powder containing a plurality of types of powder, the dispersibility of the plurality of types of powder in the powder 3 is improved when high-frequency vibration in the vicinity of the ultrasonic wave band is applied to the blade 2 to flatten the powder 3. That is, in the powder 3, a plurality of types of powder are easily dispersed, and a specific type of powder is not easily unevenly stacked on the sheet 4. This is considered to be because the high-frequency vibration in the vicinity of the ultrasonic wave band of the blade 2 is transmitted to the portion where the powder 3 is retained before reaching the blade 2, and the plurality of types of particles constituting the powder 3 vibrate and flow, whereby the plurality of types of particles constituting the powder 3 are mixed with each other, and the dispersibility is improved.

In the present embodiment, a hopper is used as the powder supplying section 11. The hopper stores the powder 3 therein, and feeds the powder 3 onto the surface 4a of the sheet 4. The hopper is disposed upstream of a position where outer peripheral surfaces of the pair of roll presses 6 are closest to each other (hereinafter, also referred to as a "pressing position") in the moving direction of the sheet 4. The powder 3 supplied onto the surface 4a of the sheet 4 reaches the pressing position as the sheet 4 moves. In the present embodiment, a hopper is used as the powder supply unit 11, but the present invention is not limited thereto, and an apparatus capable of supplying the powder 3 onto the surface 4a of the sheet 4 may be used.

The compressed powder layer 5 is a layer formed by compressing the powder 3.

As shown in fig. 1, the powder coating apparatus 1 may further include a pair of roll presses 6 as a pressing section. The pair of roll compactors 6 compress the powder 3 on the sheet 4 whose thickness is adjusted by the doctor blade 2.

The pair of roller presses 6 are each cylindrical, and are disposed such that the axial centers of the pair of roller presses 6 are substantially parallel to each other. As shown in fig. 1, a pair of roll presses 6 are disposed to sandwich the sheet 4 with a given interval therebetween. In detail, the following are set: the outer peripheral surface of one roller press 6 is opposed to one surface of the sheet 4, and the outer peripheral surface of the other roller press 6 is opposed to the other back surface of the sheet 4. The pair of roller presses 6 are rotationally driven in opposite directions (in the direction of the arrows in the pair of roller presses 6 shown in fig. 1) by a driving device (not shown).

The powder coating apparatus 1 has a blade 2. The scraper 2 makes the film thickness of the powder 3 supplied to the surface 4a of the sheet 4 uniform to reduce the variation of the film thickness. That is, the scraper 2 adjusts the thickness of the powder 3 supplied from the powder supply unit 11 onto the surface 4a of the sheet 4.

The squeegee 2 is disposed at a position downstream of the hopper in the moving direction of the sheet 4 and upstream of the pressing position in the moving direction of the sheet 4 so as to form a predetermined gap with the sheet 4.

In the powder coating apparatus 1 of the present embodiment, the powder 3 supplied from the hopper onto the surface 4a of the sheet 4 is scraped by the scraper 2 until it reaches the pressing position along with the movement of the sheet 4. Then, at the pressing position, the powder 3 supplied onto the surface of the sheet 4 is pressurized on the surface of the sheet 4. In this way, the compressed powder layer 5 is formed on the surface 4a of the sheet 4.

The blade 2 will be described in detail below with reference to fig. 1 and 2.

The scraper 2 flattens the powder 3 supplied onto the surface 4a of the sheet 4, thereby adjusting the thickness (vertical dimension in fig. 2) of the powder 3 to be constant. A predetermined gap is formed between the blade 2 and the sheet 4, and the powder 3 supplied onto the surface 4a of the sheet 4 passes through the gap. Thereby, the thickness of the powder 3 is changed to the shortest distance d between the tip of the blade 2 (the portion facing the surface 4a) and the surface 4a of the sheet 4.

The squeegee 2 is preferably configured to be movable relative to the sheet 4 so that the distance d can be changed.

In the present embodiment, the blade 2 has a trapezoidal shape as viewed from the side as shown in fig. 1. The blade 2 has a main surface 2a facing the surface 4a of the sheet 4 and inclined with respect to a plane parallel to the surface 4a, and an end surface 2b substantially parallel to the sheet 4.

The main surface 2a is inclined downward along the movement direction of the powder 3, and is a surface intersecting the movement direction of the powder 3 supplied onto the surface 4 a. The main surface 2a contacts the moving powder 3, thereby scraping the powder 3 uniformly against the surface 4 a.

The end face 2b is a face formed along the moving direction of the powder 3 and substantially parallel to the surface 4 a. The end face 2b is configured to scrape the lower edge of the main face 2a (edge closest to the surface 4a) so that the surface of the powder 3 having the thickness d (shortest distance) is further scraped by a predetermined length. The given length is the length of the end face 2b in the direction parallel to the moving direction. The end face 2b is not necessarily essential, and instead of the end face 2b, a tip portion may be used.

(mechanism of Retention)

The powder 3 comes into contact with the main surface 2a of the blade 2 when it approaches the gap between the blade 2 and the sheet 4 together with the movement of the sheet 4. At this time, since the sheet 4 moves relative to the blade 2 to apply pressure to the powder 3, in the case of the powder 3 having low fluidity, the powder 3 is accumulated and aggregated between the blade 2 and the sheet 4, and powder clogging is likely to occur.

In particular, when the powder 3 having a particle diameter of 50 μm or less is used, the flowability is liable to be lowered, and thus powder clogging is liable to occur.

In addition, in the powder 3 having a high flowability, it is difficult to make the film thickness of the powder 3 passing through the scraper 2 uniform with high accuracy due to the influence of the retention. This is because the retention and release of the powder 3 are repeated in a small range.

(high frequency vibration near ultrasonic wave band)

A uhf vibration generator 12 for vibrating the blade 2 is connected thereto. Specifically, the ultrahigh frequency vibration generator 12 applies high frequency vibration in the vicinity of the ultrasonic wave band to the blade 2, and the blade 2 vibrates in the vicinity of the ultrasonic wave band at high frequency. The ultrahigh frequency vibration generator 12 can vibrate the blade 2 at a frequency of 2kHz to 300 kHz. The ultrahigh frequency vibration generator 12 may be included in the structural elements of the powder coating apparatus 1, or may not be included in the structural elements of the powder coating apparatus 1.

The blade 2 vibrates at a frequency of 2kHz to 300kHz when the sheet 4 moves. That is, the blade 2 vibrates in a high frequency near the ultrasonic wave band while the sheet 4 moves. When the blade 2 is vibrated at a high frequency near the ultrasonic wave band, the vibration of the blade 2 is transmitted to the powder 3, and the flowability of the powder 3 is improved, thereby suppressing the clogging of the powder.

The higher the frequency of the vibration of the blade 2, the higher the fluidity of the powder 3 becomes. Therefore, the flowability of the powder 3 can be sufficiently improved by vibrating the blade 2 at a frequency of 2kHz or more in a high-frequency region near the ultrasonic wave band. However, since the high frequency near the ultrasonic wave band is easily attenuated if the frequency is too high, the vibration becomes more difficult to be transmitted as the distance from the blade 2 increases. Therefore, if the frequency is 300kHz or less, the flowability of the powder 3 can be sufficiently improved even in a portion where powder clogging is likely to occur. When the blade 2 vibrates at a high frequency near the ultrasonic wave band, the powder 3 contacting the blade 2 is less likely to receive frictional resistance due to the powder pressure, and the fluidity is improved, whereby the retention and aggregation of the powder 3 are suppressed.

In addition, also with respect to the powder 3 located near the scraper 2, the frictional force between particles constituting the powder 3 is reduced by the vibration effect caused by the scraper 2, and the fluidity is improved, whereby the aggregation of the powder is suppressed.

Accordingly, even in the powder 3 having a particle diameter of 50 μm or less and low fluidity, the powder 3 passes through the vibrating blade 2 without being accumulated or agglomerated.

Further, even in the powder 3 having a high flowability, the flowability can be further promoted, and the film thickness of the powder 3 passing through the scraper 2 can be further made uniform with high accuracy.

(Direction and magnitude of high frequency vibration in the vicinity of ultrasonic wave band)

The high-frequency vibration direction in the vicinity of the ultrasonic wave band of the blade 2 includes at least one of a vertical direction component, a horizontal direction component, and a plane direction component. That is, the blade 2 vibrates in at least any one of the vertical direction, the horizontal direction, and the planar direction.

The vertical direction is a direction perpendicular to the main surface 2a of the squeegee 2. In the embodiment shown in fig. 1, the vertical direction is substantially parallel to the X direction. The vertical vibration easily transmits a longitudinal wave (a wave in a vibration direction approaching or departing from the scraper 2 to the powder 3) to the powder 3.

The vertical component has a large effect of reducing the frictional resistance between the powders 3. Since the vibration in the vertical direction is a vibration direction approaching or separating from the scraper 2 with respect to the powder 3, the particles of the powder 3 repeatedly collide with each other, and the vibration is easily transmitted to the entire powder 3. It is also considered that the high frequency near the ultrasonic wave band has a high frequency and thus vibration is hard to be transmitted to the entire powder 3, but in the case of vibration in the vertical direction, vibration is particularly easy to be transmitted to the powder 3.

In particular, the vibration component in the vertical direction can move the powder 3 greatly in the aggregation portion where the powder 3 is easily aggregated. This makes it easier for the particles of the powder 3 to collide with each other in the aggregation portion, and the powder 3 is further dispersed.

The horizontal direction is a direction substantially parallel to the main surface 2a of the blade 2 and substantially parallel to the axial center of the blade 2. In the embodiment shown in fig. 1, the horizontal direction is substantially parallel to the Z direction. The horizontal vibration easily transmits a transverse wave (a wave in a direction vibrating from the blade 2 rubbing against the powder 3) to the powder 3. The axial center of the blade 2 means substantially parallel to the longitudinal direction of the blade 2.

The plane direction is a direction substantially parallel to the main surface 2a of the blade 2 and perpendicular to the axis of the blade 2. In the embodiment shown in fig. 1, the plane direction is substantially parallel to the Y direction. The vibration in the plane direction easily transmits a transverse wave to the powder 3 (a wave in a direction vibrating from the blade 2 by rubbing against the powder 3).

The horizontal and planar components of the high-frequency vibration in the vicinity of the ultrasonic wave band of the blade 2 contribute to a reduction in frictional resistance between the powder 3 and also contribute greatly to a reduction in frictional force between the blade 2 and the powder 3. If the vertical vibration component is excessively increased, the vibration may be excessively transmitted, and the powder 3 largely vibrates, and the film thickness deviation may become large. However, since the horizontal vibration component can also reduce the frictional force between the scraper 2 and the powder 3, the flowability of the powder 3 can be particularly improved. Further, the vibration of the blade 2 in the horizontal direction can be realized by mounting a high-frequency transducer in the axial direction of the blade 2 and connecting the end portions of the blade 2 by bearings, and therefore the device structure can be simplified with respect to the vibration in the planar direction.

The direction of the high-frequency vibration in the vicinity of the ultrasonic wave band of the blade 2 may be only the vertical direction, only the horizontal direction, or only the plane direction. However, if the high-frequency vibrations in the vicinity of the ultrasonic wave band in both the vertical direction and the horizontal direction are used in combination, the flowability of the powder 3 can be further improved. When focusing attention on the single particles of the powder 3, the vibration directions of the particles become random, and the vibration is transmitted to the entire surface of the powder 3 on the upstream side of the blade 2, so that the surface having high frictional resistance disappears without transmitting the vibration, and the fluidity is improved.

When the blade 2 vibrates at a high frequency in the vicinity of the ultrasonic wave band in the vertical direction and the horizontal direction, the magnitude of the vibration of the blade 2 in the horizontal direction is preferably larger than the magnitude of the vibration of the blade 2 in the vertical direction. That is, with respect to the blade 2, the magnitude of the vibration of the transverse wave component of the powder 3 (the direction of vibration caused by the blade 2 rubbing against the powder 3) is preferably larger than the magnitude of the vibration of the longitudinal wave component of the powder 3 (the direction of vibration caused by the blade 2 approaching or separating from the powder 3). In this case, particularly, the frictional resistance at the interface (for example, the main surface 2a and the end surface 2b) between the blade 2 and the powder 3, where the frictional resistance tends to be high, can be reduced by the horizontal vibration of the blade 2, and the frictional resistance between the powders 3 can also be reduced, so that the flowability of the powder 3 can be further improved.

The magnitude of the vibration of the blade 2 in the vertical direction, that is, the amplitude of the vibration of the blade 2 in the vertical direction is preferably 2 μm or more. In this case, the frictional resistance between the powders 3 can be sufficiently reduced, and the flowability of the powders 3 can be further improved.

The magnitude of the horizontal vibration of the blade 2 is preferably 4 μm or more. That is, the horizontal amplitude of the blade 2 is preferably 4 μm or more. In this case, the frictional resistance at the interface between the scraper 2 and the powder 3 can be sufficiently reduced, and the flowability of the powder 3 can be further improved.

(inclination angle of scraper)

The inclination angles of the scrapers 22a to 22c will be described in detail with reference to fig. 3A to 3F. The squeegees 22a to 22c are examples of the squeegees 2. Fig. 3B, 3D, and 3F illustrate the repose angle model of the powder 3. The rest angle a is an angle formed by a slope of a mountain of the powder 3 and a horizontal plane, which is formed when the powder 3 is dropped from a certain height to a sheet and the powder 3 spontaneously keeps stable in a mountain shape without scattering. Since the powder 3 flows in the direction of the outlined arrow, the arrow start point is considered to be above (upstream side) the repose angle model of the powder 3. Therefore, as shown in fig. 3B, 3D, and 3F, the powder 3 is rotated by 90 ° in a stable state in a mountain shape as shown by the two-dot chain line. The slope is indicated by a tangent line of a two-dot chain line, and the horizontal plane is indicated by the main surface 22a1 of the squeegee 22 a. Note that, while fig. 3B is merely illustrated as the rest angle a, the rest angle a is the same as that illustrated in fig. 3D and 3F, and the illustration is omitted. In fig. 3A to 3F, the sheet is not illustrated.

Fig. 3A and 3B show a case where the angle θ of the main surface 22a1 of the squeegee 22a with respect to the longitudinal direction is 0 °. The longitudinal direction means a direction perpendicular to the sheet 4 as a member (also referred to as a vertical direction of the member). The main surface 22a1 of the scraper 22a is a surface of the outer peripheral surface of the scraper 22a, which has a uniform thickness of the powder 3.

In this case, as shown in fig. 3A and 3B, when the repose angle of the powder 3 is a, the powder 3 reaching the main surface 22a1 of the scraper 22a becomes hard to be scattered, and the powder 3 is likely to be accumulated. However, since the blade 22a vibrates at a high frequency in the vicinity of the ultrasonic wave band, even if the angle θ of the main surface 22a1 of the blade 22a with respect to the longitudinal direction is 0 °, the particle fluidity is improved by the conduction of vibration to the powder 3, and the retention of the powder 3 can be reduced.

As shown in fig. 3C and 3D, the angle θ of the main surface 22b1 of the blade 22b with respect to the longitudinal direction is preferably greater than 0 °. That is, the angle θ formed by the main surface 22b1 of the scraper 22b in contact with the powder 3 with respect to the perpendicular direction of the sheet 4 is preferably greater than 0 °. Fig. 3C and 3D show the case where the angle θ is greater than 0 °. Since the powder 3 is in contact with the main surface 22b1 of the scraper 22b in the direction of the outlined arrow, if the angle θ is greater than 0 °, the stability of the powder 3 at the repose angle a is low, and the force with which the powder 3 is to stay on the main surface 22b1 of the scraper 22b is likely to be small. Therefore, the powder 3 can be prevented from being retained and aggregated to cause powder clogging.

As shown in fig. 3E and 3F, the angle θ of the main surface 22c1 of the scraper 22c with respect to the longitudinal direction is particularly preferably equal to or larger than the repose angle a of the powder 3. That is, the angle θ formed by the main surface 22c1 of the scraper 22c with respect to the direction perpendicular to the sheet 4 is particularly preferably substantially the same as the repose angle a of the powder 3. Fig. 3E and 3F show the case where the angle θ is equal to or larger than the angle of repose a. Since the powder 3 is in contact with the main surface 22c1 of the scraper 22c in the direction of the outlined arrow, if the angle θ is equal to or greater than the repose angle a, the stability of the powder 3 at the repose angle a is lower, and the force with which the powder 3 is to stay on the main surface 22c1 of the scraper 22c tends to be further reduced. Therefore, in particular, the powder 3 can be prevented from being retained and aggregated to cause powder clogging.

Modifications 1 and 2 of the blade structure will be described below.

(modification 1)

In this modification, a blade will be described. The present modification is different from embodiment 1 in that the shape of the squeegee is a circular shape in a side view. In the case where other structures in the present modification are not specifically shown, the same structures as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

In the present modification, as shown in fig. 4, the blade 102 has a curved surface 2c and a shape in which the principal surface 2a extends from the end surface toward the upstream side in the moving direction of the sheet 4. However, the shape of the squeegee 102 is not limited thereto. The scraper 102 may be of any shape as long as the thickness of the powder 3 can be adjusted, and may be, for example, an elliptical shape or a semicircular shape only on the main surface 2a of embodiment 1.

Another shape of the blade 102 will be described with reference to fig. 4. The blade 102 may be cylindrical as shown in fig. 4. Specifically, the blade 102 is preferably substantially parallel to the surface 4a of the sheet 4 and has a cylindrical shape in which the curved surface 2c and the axial center are substantially parallel.

When the powder 3 advances and comes into contact with the surface of the scraper 102, a pressure is generated on the powder 3. This makes the powder 3 easily stagnate/aggregate, and causes powder clogging. Since the scraper 102 has a cylindrical shape, the angle of contact between the powder 3 and the scraper 102 increases continuously, and eventually becomes equal to or larger than the repose angle. As a result, the pressure applied to the powder 3 is gradually reduced, does not have a special point, and is finally equal to or greater than the rest angle, and is released. Therefore, when the scraper 102 has a cylindrical shape, the powder 3 is less likely to be accumulated and aggregated.

In the case where the blade 102 is cylindrical, the high-frequency vibration direction in the vicinity of the ultrasonic wave band of the blade 102 includes at least one of a component in the horizontal direction and a component in the vertical direction. That is, the blade 102 vibrates in at least one of the horizontal direction and the vertical direction.

When the blade 102 has a cylindrical shape, the horizontal direction is a direction substantially parallel to the main surface 2a of the blade 102. In the present modification, the horizontal vibration easily transmits a transverse wave to the powder 3 (a wave in a direction vibrating from the blade 102 by rubbing against the powder 3).

When the blade 102 has a cylindrical shape, the vertical direction is a direction perpendicular to the main surface 2a of the blade 102. I.e., the direction perpendicular to the circumference of the squeegee 102. The vertical vibration easily transmits a longitudinal wave (a wave in a vibration direction approaching or departing from the scraper 102 to the powder 3) to the powder 3.

The columnar blade 102 may be slidable in the horizontal direction by fixing both ends of the blade 102 by a support with a bearing, for example. In this case, the relationship of (amplitude in the horizontal direction) > (amplitude in the vertical direction) can be established by forming the axial center of the blade 102 into a shape into which the circular bearing is inserted.

When the blade 102 has a cylindrical shape, the diameter of the cylinder is preferably 4mm or more and 300mm or less. When the diameter is 4mm or more, the change in angle is not likely to be rapid, and the effect of continuously releasing the pressure is likely to be large. By having a diameter of 300mm or less, the weight of the blade 102 does not become too heavy, and the blade 102 is easily interlocked with the operation of high-frequency vibration in the vicinity of the ultrasonic wave band, and a sufficient vibration effect can be obtained.

(modification 2)

In this modification, the blades 102 and 103 will be described. The present modification is different from embodiment 1 in that the scrapers 102 and 103 have a multi-stage shape. Other structures in this modification are the same as those in embodiment 1, and the same structures are denoted by the same reference numerals and detailed description thereof is omitted, unless otherwise explicitly stated.

Another embodiment of the scrapers 102 and 103 will be described with reference to fig. 5.

The ratio of the thickness of the powder 3 before the thickness adjustment by the scrapers 102 and 103 to the thickness of the powder 3 after the thickness adjustment by the scrapers 102 and 103 is preferably in the range of 1: 1 to 3: 1. In the present modification, since the ratio of (the thickness of the powder before passing through the scraper 103)/(the thickness of the powder 3 after passing through the scraper 102) is less than 3, the amount of the powder 3 located in front of the scraper 102 does not become excessive, and the pressure applied to the powder 3 from the main surfaces 102a and 103a of the scrapers 102 and 103 tends to be small. Therefore, the powder 3 is less likely to be retained or aggregated, and clogging of the powder can be suppressed. Further, since the ratio of (the thickness of the powder before passing through the scraper 103)/(the thickness of the powder 3 after passing through the scraper 103) and the ratio of (the thickness of the powder before passing through the scraper 102)/(the thickness of the powder 3 after passing through the scraper 102) are larger than 1, the powder 3 can be flattened well by the scrapers 102 and 103.

Further, the scraper 103 may be provided to adjust the thickness of the powder 3 before passing through the scraper 102 in advance so that the ratio of the thickness of the powder 3 before being adjusted by the thickness of the scraper 102 to the thickness of the powder 3 after being adjusted may be within the above range.

The thickness of the powder 3 before passing through the squeegee 103 may be adjusted in advance so that the ratio of the thickness of the powder 3 before being adjusted by the thickness of the squeegee 103 to the thickness of the powder 3 after being adjusted may be within the above-described range.

The scraper 103 is disposed at a position downstream of the powder supply portion 11 (hopper) in the movement direction of the powder 3 and upstream of the scraper 2 in the movement direction of the powder 3 so as to form a predetermined gap with the surface 4a of the sheet 4, which is larger than a predetermined gap between the scraper 102 and the surface 4 a. In this way, the powder coating apparatus 1 may have a multistage blade including a plurality of blades 102, 103. In this case, since the thickness of the powder 3 can be adjusted in stages, the powder 3 is less likely to be retained or aggregated, and clogging of the powder can be suppressed. Such a multistage scraper structure is useful for powder having particularly low fluidity. As shown in fig. 5, the multistage blade may include 2 blades, that is, the blades 103 and 102, or may include 3 or more blades.

The following description returns to the embodiments.

[ method for manufacturing energy device ]

A method for manufacturing an energy device, which is an embodiment of the method for manufacturing an energy device according to the present disclosure, will be described below with reference to fig. 1 and 6. In the method for manufacturing an energy device, the energy device can be manufactured using the powder coating apparatus 1 as shown in fig. 1.

As shown in fig. 1 and 6, the method of manufacturing an energy device includes: supplying the powder 3 onto the surface of the sheet 4 while moving the sheet 4 for an energy device such as a current collector in a predetermined direction (powder supplying step S10); the thickness of the powder 3 supplied onto the surface of the sheet 4 is adjusted using the scraper 2 (powder aligning step S20).

First, in the method for manufacturing an energy device, the powder 3 is manufactured. The raw material of the powder 3 is not particularly limited, and for example, a particle group containing an active material may be used. The powder 3 is prepared by mixing a substance obtained by adding an appropriate additive (e.g., a conductive material) to an active material and a binder. As a method of mixing, for example, a method of mixing by a mortar, a ball mill, a stirrer, or the like is available. In particular, a method of mixing the powder 3 without using a solvent or the like is preferable because the material is not deteriorated.

In the powder supplying step S10, the powder 3 is supplied onto the surface of the sheet 4 by using the powder supplying unit 11 such as a hopper while moving the sheet 4 in a predetermined direction. The sheet 4 may be sheet-like.

The powder aligning step S20 is a step of aligning the powder 3 on the surface 4a of the sheet 4 using the blade 2 of the powder coating apparatus 1. That is, in the powder aligning step S20, the thickness of the powder 3 supplied onto the surface 4a of the sheet 4 is adjusted to be flat by using the scraper 2. At this time, the blade 2 vibrates at a frequency of 2kHz to 300 kHz.

The method for manufacturing an energy device further includes a powder sheet forming step S30. The powder sheet forming step S30 is a step of compressing the powder 3 arranged on the sheet 4 by using the roll press 6 of the powder coating apparatus 1. Thereby, the compressed powder layer 5 in which the powder 3 is compressed is formed on the surface 4a of the sheet 4.

As described above, in the method for manufacturing an energy device, the powder supplying step S10, the powder aligning step S20, and the powder sheet forming step S30 are sequentially performed, whereby the compressed powder layer 5 containing the powder 3 is formed on the surface 4a of the sheet 4. Such a laminate of the sheet 4 and the compressed powder layer 5 can be used in an energy device. For example, when a current collector is used as the sheet 4 and an active material is used as the powder 3, an electrode for an energy device can be manufactured.

The energy device manufactured using the powder coating apparatus 1 can have the compressed powder layer 5 with less variation in thickness even if the powder 3 having low fluidity is used. Therefore, according to the method for manufacturing an energy device, since it is not necessary to perform a granulation step for improving the flowability of the powder 3, it is possible to prevent the deterioration of the material and suppress the increase in cost. Further, since the thickness of the compressed powder layer 5 is uniform, the characteristics as an electrode in an energy device can be improved, and an energy device having good quality (output or the like) can be manufactured at low cost.

[ Positive and negative electrodes for batteries ]

Hereinafter, one embodiment of the positive electrode and the negative electrode for a battery according to the present disclosure will be described with reference to fig. 7 and 8. Fig. 7 is a cross-sectional view of a positive electrode of an all-solid battery according to an embodiment of the present disclosure. Fig. 8 is a cross-sectional view of the negative electrode of the all-solid battery according to one embodiment of the present disclosure. The positive electrode and the negative electrode of the present embodiment can be used for an all-solid battery, for example.

As shown in fig. 7 and 8, the all-solid-state battery includes, for example: the solid electrolyte layer includes a pair of electrodes including a positive electrode and a negative electrode, and a solid electrolyte layer disposed between the pair of electrodes. The positive electrode includes a positive electrode current collector 54 and a positive electrode mixture layer 53. The negative electrode includes a negative electrode current collector 64 and a negative electrode mixture layer 63. Positive electrode mixture layer 53 and negative electrode mixture layer 63 can be produced using powder coating apparatus 1 described above. The negative electrode is described later. The positive electrode is an example of the positive electrode layer or positive electrode mixture layer 53. The negative electrode is an example of the negative electrode layer or negative electrode mixture layer 63 described later.

As shown in fig. 7, positive electrode mixture layer 53 is formed on positive electrode current collector 54, and contains positive electrode active material 51 and solid electrolyte 52 having ion conductivity. Positive electrode mixture layer 53 and positive electrode current collector 54 constitute a positive electrode.

The concentration of the solvent contained in positive electrode mixture layer 53 is 50ppm or less. That is, positive electrode mixture layer 53 contains substantially no solvent. The substantial absence means a case where the inclusion is completely absent and a case where the inclusion is inevitably 50ppm or less as an impurity or the like. The solvent means an organic solvent. The method of measuring the solvent is not particularly limited, and for example, measurement can be performed by using a gas chromatograph, a mass spectrometry, or the like. Examples of the organic solvent include: nonpolar organic solvents such as heptane, xylene, and toluene; polar organic solvents such as tertiary amine solvents, ether solvents, thiol solvents, and ester solvents; and combinations thereof. Examples of the tertiary amine-based solvent include triethylamine, tributylamine, and tripentylamine. Examples of the ether solvent include tetrahydrofuran and cyclopentylmethyl ether. Examples of the thiol-based solvent include ethanethiol. Examples of ester-based solvents include butyl butyrate, ethyl acetate, and butyl acetate.

The area of positive electrode mixture layer 53 was 900mm²The above. The thickness of positive electrode mixture layer 53 is 15 μm or more.

The variation in thickness Tp of positive electrode mixture layer 53 is ± 5% or less. That is, when the average film thickness of positive electrode mixture layer 53 is Tp, the minimum value and the maximum value of the film thickness of positive electrode mixture layer 53 are within the range of Tp ± 5%.

Since positive electrode mixture layer 53 is produced using powder coating apparatus 1, even if produced using powder 3 having low fluidity (positive electrode active material 51 having an average particle diameter of 50 μm or less and solid electrolyte powder), positive electrode mixture layer 53 as compressed powder layer 5 has small variations in thickness and can be easily formed to have a uniform thickness. Further, by using the powder coating apparatus 1, a 900mm area can be manufactured²Large high-capacity positive electrode mixture layer 53 having a thickness of 15 μm or more. Further, positive electrode mixture layer 53 is produced through a coating process that does not include a solvent, and therefore is not damaged by the solvent. Therefore, in the positive electrode of the all-solid battery, large-sized and high-capacity positive electrode mixture layer 53 having excellent quality with little variation in film thickness and high output can be obtained.

The average particle diameter (D50) of the positive electrode active material 51 is preferably 50 μm or less. By using an active material having a small particle diameter, the surface area becomes large and a high capacity can be achieved.

Further, it is preferable that solid electrolyte 52 in positive electrode mixture layer 53 be kept in a well dispersed state. When the cross section of positive electrode mixture layer 53 is observed, the cross section is more preferably 100 μm²The total area of the aggregated portions of solid electrolyte 52 is 2% or less with respect to the cross-sectional area of positive electrode mixture layer 53. In this case, by dispersing solid electrolyte 52 in positive electrode mixture layer 53 well, solid electrolyte 52 can be used flexibly without waste, and a positive electrode mixture having high capacity characteristics can be obtainedAnd an agent layer 53.

By applying high-frequency vibration in the vicinity of the ultrasonic wave band to the blade 2, the powder 3 containing the solid electrolyte 52 can be flattened, and the dispersibility of the solid electrolyte 52 can be improved. By the high-frequency vibration in the vicinity of the ultrasonic wave band, the high-frequency vibration in the vicinity of the ultrasonic wave band is applied to the powder 3 at the portion where the powder 3 is collected on the upstream side of the scraper 2, and the powder 3 flows while vibrating. Thereby, the powders 3 are mixed with each other, and thus the solid electrolyte 52 in the powder 3 is well dispersed.

The positive electrode active material 51 is a material in which metal ions such as lithium (Li) are inserted into or released from the crystal structure at a potential higher than that of the negative electrode, and are oxidized or reduced with the insertion or release of the metal ions such as lithium. The type of the positive electrode active material 51 is appropriately selected according to the type of the all-solid battery, and examples thereof include an oxide active material and a sulfide active material.

The positive electrode active material 51 in the present embodiment is, for example, an oxide active material (lithium-containing transition metal oxide). As the oxide active material, for example, LiCoO can be mentioned₂、LiNiO₂、LiMn₂O₄、LiCoPO₄、LiNiPO₄、LiFePO₄、LiMnPO₄And compounds obtained by substituting 1 or 2 different kinds of elements for the transition metals of these compounds. As the compound obtained by substituting the transition metal of the above compound with 1 or 2 different kinds of elements, LiNi can be used_1/3Co_1/3Mn_1/3O₂、LiNi_0.8Co_0.15Al_0.05O₂、LiNi_0.5Mn_1.5O₂And the like known materials. The positive electrode active material 51 may be used as 1 species, or 2 or more species may be used in combination.

Examples of the positive electrode active material 51 include particles and films. When the positive electrode active material 51 is in the form of particles, the average particle diameter (D50) of the positive electrode active material 51 is, for example, preferably in the range of 50nm to 50 μm, and more preferably in the range of 1 μm to 15 μm. The range is preferable because the operability is easily improved by setting the average particle diameter of the positive electrode active material 51 to 50nm or more, and a high-capacity positive electrode is easily obtained by setting the average particle diameter to 50 μm or less. In the present specification, the "average particle diameter" is a volume-based average diameter measured by a laser analysis and scattering particle size distribution measuring apparatus.

The content of the positive electrode active material 51 in the positive electrode mixture layer 53 is not particularly limited, but is, for example, preferably in the range of 40 wt% to 99 wt%, and more preferably 70 wt% to 95 wt%.

The surface of the positive electrode active material 51 may be coated with a coating layer. This is because the reaction between the positive electrode active material 51 (for example, an oxide active material) and the solid electrolyte 52 (for example, a sulfide-based solid electrolyte) can be suppressed. Examples of the material of the coating layer include LiNbO₃、Li₃PO₄And Li ion conductive oxides such as LiPON. The average thickness of the coating layer is, for example, preferably in the range of 1nm to 20nm, more preferably in the range of 1nm to 10 nm.

When the ratio of positive electrode active material 51 to solid electrolyte 52 contained in positive electrode mixture layer 53 is a weight ratio of (positive electrode active material)/(solid electrolyte) by weight conversion, the weight ratio is preferably in the range of 1 to 19, more preferably in the range of 2.3 to 19. The reason why the weight ratio is preferably in the range is because both lithium ion conduction paths and electron conduction paths are easily ensured in positive electrode mixture layer 53.

The solid electrolyte 52 may be appropriately selected according to the kind of conductive ions (for example, lithium ions), and can be roughly classified into a sulfide-based solid electrolyte and an oxide-based solid electrolyte, for example.

The type of the sulfide-based solid electrolyte in the present embodiment is not particularly limited, and examples of the sulfide-based solid electrolyte include Li₂S-SiS₂、LiI-Li₂S-SiS₂、LiI-Li₂S-P₂S₅、LiI-Li₂S-P₂O₅、LiI-Li₃PO₄-P₂S₅And Li₂S-P₂S₅And the like, particularly, since lithium ion conductivity is excellent, Li, P, and S are preferably contained. The sulfide-based solid electrolyte may be used as 1 species, or 2 or more species may be used in combination. The sulfide-based solid electrolyte may be crystalline, amorphous, or glass ceramic. In addition, the above-mentioned "Li₂S-P₂S₅"the description means that Li is contained₂S and P₂S₅The sulfide-based solid electrolyte formed from the raw material components of (1) is the same as described in other descriptions.

In the present embodiment, one embodiment of the sulfide-based solid electrolyte is a solid electrolyte containing Li₂S and P₂S₅Sulfide glass-ceramics of, Li₂S and P₂S₅The ratio of (A) is Li in terms of mol₂S/P₂S₅When the molar ratio is equal to the molar ratio, the molar ratio is preferably in the range of 2.3 or more and 4 or less, and more preferably in the range of 3 or more and 4 or less. The reason why the molar ratio is preferably in the range is that a crystal structure having high ion conductivity can be obtained while maintaining the lithium concentration that affects the battery characteristics.

The shape of the sulfide-based solid electrolyte in the present embodiment includes, for example, a particle shape such as a spherical shape or an ellipsoidal shape, a thin film shape, and the like. When the sulfide-based solid electrolyte material is in the form of particles, the average particle diameter (D50) of the sulfide-based solid electrolyte is not particularly limited, but is preferably 40 μm or less, more preferably 50 μm or less, and still more preferably 10 μm or less, because the filling ratio in the positive electrode can be easily increased. On the other hand, the average particle size of the sulfide-based solid electrolyte is preferably 0.001 μm or more, and more preferably 0.01 μm or more. The average particle size can be determined by, for example, image analysis using a particle size distribution meter or SEM (Scanning Electron Microscope).

Next, the oxide-based solid electrolyte in the present embodiment will be described. Oxygen gasThe type of the compound-based solid electrolyte is not particularly limited, but examples thereof include LiPON and Li₃PO₄、Li₂SiO₂、Li₂SiO₄、Li_0.5La_0.5TiO₃、Li_1.3Al_0.3Ti_0.7(PO₄)₃、La_0.51Li_0.34TiO_0.74、Li_1.5Al_0.5Ge_1.5(PO₄)₃And the like. The oxide solid electrolyte may be used in 1 type, or 2 or more types may be used in combination.

The all-solid-state battery in the present embodiment includes, for example, a positive electrode current collector 54 including a metal foil or the like. For example, a foil, a plate, a mesh, or the like containing aluminum, gold, platinum, zinc, copper, SUS, nickel, tin, titanium, or an alloy of 2 or more of these can be used for the positive electrode current collector 54.

The thickness, shape, and the like of the positive electrode current collector 54 may be appropriately selected according to the application of the all-solid battery.

Next, the negative electrode will be described with reference to fig. 8.

As shown in fig. 8, negative electrode mixture layer 63 is formed on negative electrode current collector 64, and contains negative electrode active material 61 and solid electrolyte 52 having ion conductivity. Negative electrode mixture layer 63 and negative electrode current collector 64 constitute a negative electrode.

The concentration of the solvent contained in negative electrode mixture layer 63 is 50ppm or less. That is, negative electrode mixture layer 63 contains substantially no solvent. The substantial absence means a case where the inclusion is completely absent and a case where the inclusion is inevitably 50ppm or less as an impurity or the like. The solvent means an organic solvent, and examples of the solvent contained in negative electrode mixture layer 63 are the same as those exemplified as the solvent contained in positive electrode mixture layer 53. The method of measuring the solvent is not particularly limited, and for example, measurement can be performed by using a gas chromatograph, a mass spectrometry, or the like.

The area of the negative electrode mixture layer 63 was 900mm²The above. The thickness of negative electrode mixture layer 63 is 15 μm or more.

The variation in thickness Tn of negative electrode mixture layer 63 is ± 10% or less. That is, when the average film thickness of negative mixture layer 63 is Tn, the minimum value and the maximum value of the film thickness of negative mixture layer 63 are within the range of Tn ± 10%.

Since the negative-electrode mixture layer 63 is produced using the powder coating apparatus 1, even if the negative-electrode mixture layer is produced using the powder 3 having low fluidity (the negative-electrode active material 61 having an average particle diameter of 50 μm or less and the solid electrolyte powder), the negative-electrode mixture layer 63 as the compressed powder layer 5 has small variations in thickness and can be easily formed with a uniform thickness. Further, by using the powder coating apparatus 1, a 900mm area can be manufactured²Large high-capacity negative electrode mixture layer 63 having a thickness of 15 μm or more. Further, since negative electrode mixture layer 63 is produced through a coating process that does not include a solvent, there is no damage caused by the solvent. Therefore, in the negative electrode of the all-solid battery, large-sized and high-capacity negative electrode mixture layer 63 having excellent quality with little variation in film thickness and high output can be obtained.

The average particle diameter (D50) of the negative electrode active material 61 is preferably 50 μm or less. By using an active material having a small particle diameter, the surface area becomes large, and a high capacity can be achieved.

The negative electrode active material 61 is a material in which metal ions such as lithium are inserted into or released from the crystal structure at a potential lower than that of the positive electrode, and are oxidized or reduced with the insertion or release of the metal ions such as lithium.

As the negative electrode active material 61 in the present embodiment, for example, an alloying metal with lithium such as lithium, indium, tin, and silicon, a carbon material such as hard carbon and graphite, and Li can be used₄Ti₅O₁₂、SiO_xAnd known materials such as oxide active materials. As the negative electrode active material 61, a composite obtained by appropriately mixing the negative electrode active materials 61 described above, or the like may be used.

When the ratio of negative electrode active material 61 to solid electrolyte 52 contained in negative electrode mixture layer 63 is a negative electrode active material/solid electrolyte weight ratio by weight conversion, the weight ratio is preferably in the range of 0.6 or more and 19 or less, and more preferably in the range of 1 or more and 5.7 or less. The reason why the weight ratio is preferably in this range is because both lithium ion conduction paths and electron conduction paths can be ensured in negative electrode mixture layer 63.

The negative electrode in the present embodiment includes a negative electrode current collector 64 including, for example, a metal foil. For example, a foil, plate, mesh, or the like containing SUS, gold, platinum, zinc, copper, nickel, titanium, tin, or an alloy of 2 or more of these metals can be used for the negative electrode current collector 64.

The thickness, shape, and the like of the negative electrode current collector 64 may be appropriately selected according to the application of the all-solid battery.

(example 1)

The present disclosure will be specifically described below with reference to example 1. The present disclosure is not limited to the following example 1.

In example 1 and comparative example 1, the shape of the squeegee was a cylindrical shape, and experiments were performed using a powder having a repose angle of 45 ° and an average particle diameter of 1.5 μm, and the thickness variation of the powder after passing through the squeegee was compared. The results are shown in FIG. 10. The vibration frequency in fig. 10 is the vibration frequency of the blade. The powder film thickness variation is a ratio of a value having a standard deviation of 3 times of the powder film thickness to the powder film thickness.

(example 2)

The present disclosure will be specifically described below with reference to example 2. The present disclosure is not limited to the following examples.

In examples 2 to 5 and comparative examples 2 to 4, the shape of the scraper was a flat plate shape, and a simulation was performed in the case of using a powder having a resting angle of 46 ° and an average particle diameter of 10 μm, and the ratio of the retained particles was analyzed. The vibration frequency of the blade was 2.5 kHz. The results are shown in FIG. 11. The angle in fig. 11 is an angle formed between a direction perpendicular to the sheet for conveying the powder and the main surface of the blade. In examples 2 to 5, the film having a lower retained powder ratio was stable. The retained powder ratio is a ratio of the powder retained by the scraper, and is a ratio of the number of powder at a speed of 15% or less of the powder conveying speed to the total number of powder. If the ratio of the powder retained is high, powder clogging in the blade is induced, and film thickness variation of the powder coating film is induced.

Industrial applicability

The powder coating apparatus of the present disclosure can produce a uniform powder layer with little variation in film thickness without using a solvent, and thus can be applied to applications such as a mixture layer of a high-quality all-solid battery.