KR20240145831A - Powder supply apparatus for dry electrode - Google Patents

Abstract

A powder supply device for a dry electrode is disclosed. According to one embodiment of the present invention, a powder supply device for a dry electrode includes: a vacuum conveyor having a powder transport section for transporting powder for a dry electrode; a powder cover section coupled to the powder transport section of the vacuum conveyor and covering the powder; a spray nozzle section coupled to the powder cover section for spraying a fluid; and a stand on which the powder is placed.

Description

{POWDER SUPPLY APPARATUS FOR DRY ELECTRODE}

The present invention relates to a powder supply device for a dry electrode, and more specifically, to a powder supply device for a dry electrode capable of uniformly supplying powder.

Recently, interest in energy storage technology has been increasing. As the application fields are expanding to include energy for mobile phones, camcorders, notebook PCs, and even electric vehicles, efforts to research and develop electrochemical devices are becoming more specific.

Electrochemical devices are the most notable field in this regard, and among them, the development of rechargeable secondary batteries is the focus of attention. Recently, in developing secondary batteries, research and development on new electrode and battery designs are actively being conducted to improve capacity density and specific energy.

Among the secondary batteries currently in use, lithium secondary batteries developed in the early 1990s are receiving attention due to their advantages of higher operating voltage and much higher energy density than conventional batteries such as Ni-MH, Ni-Cd, and sulfuric acid-lead batteries that use aqueous electrolytes.

While expectations for these electrochemical devices are increasing, electrochemical devices are also required to be further improved in terms of low resistance, high capacity, mechanical properties, and productivity along with the expansion and development of their applications. In this situation, a manufacturing method with higher productivity is also required for electrodes for electrochemical devices.

Electrodes for electrochemical devices are typically formed by laminating an electrode active material layer on a current collector by binding an electrode active material and a conductive material used as needed with a binder. Electrodes for electrochemical devices include coated electrodes manufactured by applying a slurry for coated electrodes containing an electrode active material, a binder, a conductive material, etc., on a current collector and removing the solvent by heat or the like.

In these methods, energy is required to dry the polymer film or remove the solvent from the slurry for the coating electrode, which increases the cost and also makes it difficult to improve productivity.

Therefore, a method of manufacturing an electrode by a dry method without using a slurry for a coating electrode is proposed. This is known as a technology of producing an electrode by mixing an electrode active material, a binder, and a conductive material without a liquid medium such as a solvent or dispersion medium, and then passing the powder mixture through a rolling roll to manufacture a film.

Here, a vacuum conveyor can be used in the process of transporting the powder mixture, which is a powder, to the rolling roll.

Figure 1 is a drawing showing a powder falling from a conventional vacuum conveyor and accumulating.

Referring to Fig. 1, when powder (3) is transported using a conventional vacuum conveyor (1), powder (3) dropped from the hopper (2) of the vacuum conveyor (1) is piled up in a shape like a mountain with the center high. If the powder (3) is piled up high only in the center like this, there is a problem in that it is not loaded evenly in the next process.

Accordingly, the technical problem to be achieved by the present invention is to provide a powder supply device for a dry electrode capable of uniformly supplying powder when transporting powder through a vacuum conveyor.

According to one aspect of the present invention, a powder supply device for a dry electrode may be provided, including a vacuum conveyor having a powder transport section for transporting powder for a dry electrode; a powder cover section coupled to the powder transport section of the vacuum conveyor and covering the powder; a spray nozzle section coupled to the powder cover section for spraying a fluid; and a stand on which the powder is placed.

In one embodiment, the powder cover part is positioned on the upper side of the pedestal, and the powder transport part can be coupled to the upper side of the powder cover part.

In one embodiment, the powder cover part may include a body part formed with a diameter that increases from the top to the bottom; and an opening formed on the top of the body part to which the powder conveying part is coupled.

In one embodiment, the body portion may be formed in a conical shape.

In one embodiment, the spray nozzle section is provided in multiple units, and the multiple spray nozzle sections can be respectively coupled to the powder cover section at preset intervals.

In one embodiment, the number of the plurality of spray nozzle sections is four, and the four spray nozzle sections can be respectively coupled to the powder cover section at 90-degree intervals.

In one embodiment, the four injection nozzle sections may be arranged to sequentially inject fluid in a clockwise or counterclockwise direction from one of the injection nozzle sections.

In one embodiment, the four injection nozzles may be configured to all inject fluid at one time.

In one embodiment, a compressed air providing unit is coupled to the injection nozzle unit, and compressed air provided from the compressed air providing unit can be injected through the injection nozzle unit.

In one embodiment, the device may further include a regulator for controlling the pressure of compressed air provided from the compressed air supply unit.

Embodiments of the present invention have the effect of uniformly supplying powder when transporting powder through a vacuum conveyor.

Figure 1 is a drawing showing a powder falling from a conventional vacuum conveyor and accumulating.
FIG. 2 is a schematic drawing of a powder supply device for a dry electrode according to one embodiment of the present invention.
Figure 3 is a plan view of Figure 2.
FIG. 4 is a perspective view of a powder cover portion of a powder supply device for a dry electrode according to one embodiment of the present invention.
FIGS. 5 and 6 are drawings illustrating a process of spraying compressed air to uniformly distribute powder in a powder supply device for a dry electrode according to one embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the attached drawings according to preferred embodiments. The terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his own invention in the best way. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, and it should be understood that there may be various equivalents and modified examples that can replace them at the time of the present application.

In the drawings, the size of each component or a specific part of the component is exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect the actual size. If it is judged that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, such description will be omitted.

The term 'joint' or 'connection' as used herein includes not only cases where one member and another member are directly joined or directly connected, but also cases where one member is indirectly joined or indirectly connected to another member through a connecting member.

FIG. 2 is a schematic drawing of a powder supply device for a dry electrode according to one embodiment of the present invention, FIG. 3 is a plan view of FIG. 2, FIG. 4 is a perspective view of a powder cover part in a powder supply device for a dry electrode according to one embodiment of the present invention, and FIGS. 5 and 6 are drawings illustrating a process of spraying compressed air to uniformly distribute powder in a powder supply device for a dry electrode according to one embodiment of the present invention.

Referring to the drawings, a powder supply device (10) for a dry electrode according to one embodiment of the present invention includes a vacuum conveyor (100), a powder cover part (200), a spray nozzle part (300), and a stand (400).

Referring to FIG. 2, the vacuum conveyor (100) transports fine powder (700) for dry electrodes having various sizes for manufacturing dry electrodes. Even when simply referred to as powder (700) below, it should be understood that this means powder (700) for dry electrodes.

Here, the powder for dry electrode (700) is in a powder state that does not contain a solvent, and may include electrode active materials (positive electrode active materials and negative electrode active materials), a binder, a conductive material, a filler, etc.

The cathode active material may include, but is not limited to, lithium transition metal oxide; lithium metal iron phosphate; lithium nickel-manganese-cobalt oxide; an oxide in which some of the lithium nickel-manganese-cobalt oxide is substituted with another transition metal; or two or more of them. For example, the cathode active material may include, but is not limited to, layered compounds such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or compounds substituted with one or more transition metals; lithium manganese oxide having the chemical formula Li _1+x Mn _2-x O ₄ (wherein, x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO _{2 ,} etc.; lithium copper oxide (Li ₂ CuO ₂ ); vanadium oxide such as LiV ₃ O ₈ , LiV ₃ O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ ; Ni-site type lithium nickel oxide represented by the chemical formula LiNi _1-x M _x O ₂ (wherein, M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3); lithium manganese composite oxide represented by the chemical formula LiMn _2-x M _x O ₂ (wherein, M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (wherein, M = Fe, Co, Ni, Cu or Zn); lithium metal phosphate LiMPO ₄ (wherein, M is M = Fe, CO, Ni, or Mn); Lithium nickel-manganese-cobalt oxide Li _1+x (Ni _a Co _b Mn _c ) _1-x O ₂ (x = 0 to 0.03, a = 0.3 to 0.95, b = 0.01 to 0.35, c = 0.01 to 0.5, a+b+c=1); Lithium nickel-manganese-cobalt oxide partially substituted with aluminum oxide Li _a [Ni _b Co _c Mn _d Al _e ] _1-f M1 _f O ₂ (M1 is at least one selected from the group consisting of Zr, B, W, Mg, Ce, Hf, Ta, La, Ti, Sr, Ba, F, P, and S, and 0.8≤a≤1.2, 0.5≤b≤0.99, 0<c<0.5, 0<d<0.5, 0.01≤e≤0.1, 0≤f≤0.1); Lithium nickel-manganese-cobalt oxide, in which some of the atoms are substituted with other transition metals, Li _1+x (Ni _a Co _b Mn _c M _d ) _1-x O ₂ (x = 0 to 0.03, a = 0.3 to 0.95, b = 0.01 to 0.35, c = 0.01 to 0.5, d = 0.001 to 0.03, a+b+c+d=1, M is any one selected from the group consisting of Fe, V, Cr, Ti, W, Ta, Mg, and Mo), disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , but are not limited thereto.

And, the negative active material is, for example, carbon such as non-graphitizable carbon, graphite carbon; metal composite oxides such as Li _x Fe ₂ O ₃ (0≤x ≤1), Li _x WO ₂ (0≤x≤1), Sn _x Me _1-x Me' _y O _z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of group 1, 2, and 3 of the periodic table, halogen; 0≤x≤1; 1≤y≤3; 1≤z≤8); lithium metal; lithium alloy; silicon alloy; tin alloy; silicon oxides such as SiO, SiO/C, SiO ₂ ; Metal oxides such as SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb _{2 O 4 , Sb 2 O 5 ,} GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ and Bi ₂ O ₅ ; conductive polymers such as polyacetylene; Li-Co-Ni based materials; or two or more of these, but are not limited thereto.

And, the binder polymer included in the powder (700) may include PTFE (Polytetrafluoroethylene), polyolefin, or a mixture thereof. For example, the binder polymer may include PTFE in an amount of 60 wt% or more based on the total weight. At this time, the binder polymer may additionally include at least one of PEO (polyethylene oxide), PVdF (polyvinylidene fluoride), PVdF-HFP (polyvinylidene fluoride-cohexafluoropropylene), and a polyolefin-based polymer.

And, the conductive material that can be included in the powder (700) may include a material that is conductive without causing a chemical change in the secondary battery. For example, the conductive material may include graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, etc.; conductive fibers such as carbon fibers or metal fibers; metal powder such as fluorinated carbon, aluminum, and nickel powder; conductive whiskey such as zinc oxide or potassium titanate; conductive metal oxide such as titanium oxide; conductive materials such as polyphenylene derivatives; or two or more of these. The conductive material may include at least one selected from the group consisting of activated carbon, graphite, carbon black, and carbon nanotubes for uniform mixing and improved conductivity. Meanwhile, when considering the manufacturing process of the electrode mixture for dry electrodes, linear conductive materials such as carbon fibers may be included in the powder (700) to a minimum or may not be included since it is difficult to achieve high dispersion.

And, the filler that can be included in the powder (700) may include a fibrous material that does not cause chemical changes in the secondary battery as a component that suppresses expansion of the electrode. For example, the filler may include an olefin polymer such as polyethylene or polypropylene; a fibrous material such as glass fiber or carbon fiber; or two or more of these.

Referring to FIG. 2, the vacuum conveyor (100) may be equipped with a hopper (110) and a powder transport unit (120).

The hopper (110) is configured to receive powder (700). The shape of the hopper (110) may vary, and for example, it may be formed in a shape in which the upper side is wide and the diameter becomes narrower as it goes toward the lower side.

And, the powder transport unit (120) is configured to be connected to the hopper (110) and to transport powder (700) for a dry electrode. That is, the powder (700) fed into the hopper (110) can be configured to fall to the stand (400) through the powder transport unit (120).

Referring to FIG. 2 and FIG. 5 together, the powder cover part (200) is coupled to the powder transport part (120) of the vacuum conveyor (100), and the powder cover part (200) is configured to cover the powder (700). That is, by covering the powder (700) with the powder cover part (200), the powder (700) does not fall out of the powder cover part (200) but is located inside the powder cover part (200).

The powder cover part (200) is positioned on the upper side of the stand (400), and the powder transport part (120) can be coupled to the upper side of the powder cover part (200). That is, the powder (700) moves to the inside of the powder cover part (200) and is loaded onto the stand (400) through the powder transport part (120) coupled to the upper side of the powder cover part (200). In addition, since the powder (700) is surrounded by the powder cover part (200), it does not fall out of the powder cover part (200) as described above.

Referring to Fig. 4, the powder cover part (200) may be configured to include a body part (210) and an opening part (220). The body part (210) may be formed to have a diameter that increases from the upper side to the lower side. That is, the body part (210) may be formed in the form of an upper-lower narrow space in which the upper side is wide and the lower side is narrow.

The body part (210) can be formed in various shapes, for example, it can be formed in a cone-shaped shape, but the shape of the body part (210) is not limited thereto.

And, the opening (220) can be formed on the upper side of the body (210) and configured to allow the powder conveying unit (120) to be coupled. The size of the opening (220) can vary and is formed to a size appropriate for the powder to fall.

Referring to FIG. 4, a joining opening (230) may be formed on the side of the powder cover part (200). Then, a spray nozzle part (300) is joined to the joining opening (230) of the powder cover part (200) as shown in FIGS. 2 and 3.

The spray nozzle part (300) is configured to be coupled to the powder cover part (200) and spray the fluid. Referring to FIGS. 2 and 3, the spray nozzle part (300) may be provided in multiple units.

It is preferable to have multiple spray nozzles (300) to evenly disperse the powder (700), but a case where only one spray nozzle (300) is provided may also be considered, and this is also within the scope of the present invention as an embodiment.

When a plurality of spray nozzle parts (300) are provided, the plurality of spray nozzle parts (300) can be respectively coupled to the powder cover part (200) at preset intervals. Various embodiments are possible. For example, referring to FIG. 3, the plurality of spray nozzle parts (300) can be four, and the four spray nozzle parts (300a, 300b, 300c, 300d) can be respectively coupled to the powder cover part (200) at 90-degree intervals.

However, the number of multiple injection nozzle parts (300) is not limited to four, and more diverse embodiments are possible. In addition, the interval between multiple injection nozzle parts (300) is not limited to 90 degrees, and embodiments in which they are arranged at irregular intervals as well as regular intervals are also possible.

And, as one embodiment, four injection nozzle parts (300a, 300b, 300c, 300d) may be arranged to sequentially inject fluid in a clockwise or counterclockwise direction from one injection nozzle part (300).

Referring to FIG. 3, for example, first, a fluid is sprayed from a first injection nozzle part (300a), and then, a fluid is sprayed from a neighboring second injection nozzle part (300b) arranged at a 90-degree angle from the first injection nozzle part (300a).

And then, fluid is sprayed from the neighboring third injection nozzle unit (300c) arranged at a 90-degree angle from the second injection nozzle unit (300b). And then, fluid is sprayed from the neighboring fourth injection nozzle unit (300d) arranged at a 90-degree angle from the third injection nozzle unit (300c).

As shown in Fig. 5, when four spray nozzles (300) sequentially spray fluid toward the powder (700) with the center piled up like a mountain, the powder (700) is dispersed, spread out, flattened, and evenly distributed as shown in Fig. 6.

Here, as described above, since the powder cover part (200) is configured to cover the powder (700), even if fluid is sprayed from the spray nozzle part (300), the powder (700) does not fall out of the powder cover part (200).

Meanwhile, in another embodiment, four injection nozzle parts (300a, 300b, 300c, 300d) may be configured to all inject fluid at once. For example, in FIG. 3, the first injection nozzle part (300a), the second injection nozzle part (300b), the third injection nozzle part (300c), and the fourth injection nozzle part (300d) may all be configured to inject fluid at once.

Of course, the spraying method by the spray nozzle unit (300) is not limited to what was described above, and may be sprayed randomly rather than sequentially from the four spray nozzle units (300a, 300b, 300c, 300d), may be sprayed two at a time, or may be sprayed from the first spray nozzle unit (300a) and then from the third spray nozzle unit (300c).

Additionally, more variant embodiments are possible.

Through this configuration, the powder (700) loaded on the upper side of the stand (400) can be evenly spread out even if the center is piled high in a shape like a mountain. In addition, the powder (700) that is evenly spread out can be supplied so that it can be evenly loaded in the next process.

In addition, referring to FIGS. 2 and 3, in one embodiment, a compressed air supply unit (500) may be coupled to the spray nozzle unit (300). That is, the fluid sprayed through the spray nozzle unit (300) may be compressed air. However, the fluid sprayed through the spray nozzle unit (300) is not limited to compressed air and may include various fluids.

When the injection nozzle part (300) is connected to the compressed air supply part (500), the compressed air provided from the compressed air supply part (500) is sprayed through the injection nozzle part (300) to spread and flatten the powder (700) accumulated inside the powder cover part (200).

And, the regulator (600) can be coupled to the compressed air supply unit (500). The regulator (600) is configured to regulate the pressure of compressed air provided from the compressed air supply unit (500).

Powder (700) is placed on the stand (400). The stand (400) may be various and may be a general stand (400), but may also be a part of a roll press feeder for transporting the powder (700) to the next process.

Hereinafter, the operation and effect of a powder supply device (10) for a dry electrode according to one embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 2 and FIG. 5, powder (700) for dry electrodes, which is dropped from a vacuum conveyor (100) through a powder conveyor (120) to a stand (400), is loaded on the upper side of the stand (400) inside a powder cover (200). At this time, the powder (700) may be piled up in a shape like a mountain with a high center.

Referring to FIGS. 2 and 3 together, a spray nozzle part (300) is coupled to the powder cover part (200). A plurality of spray nozzle parts (300), for example, four, may be provided and coupled to the powder cover part (200) at 90-degree intervals.

Four spray nozzle parts (300a, 300b, 300c, 300d) coupled to the powder cover part (200) can sequentially spray toward the powder (700) from any one of the spray nozzle parts (300), for example, from the first spray nozzle part (300a) to the fourth spray nozzle part (300d).

Alternatively, four spray nozzle parts (300a, 300b, 300c, 300d), i.e., the first spray nozzle part (300a), the second spray nozzle part (300b), the third spray nozzle part (300c), and the fourth spray nozzle part (300d), may all be sprayed together at once toward the powder (700).

Referring to Fig. 5, when no fluid is sprayed from the spray nozzle (300), the center of the powder (700) is piled high. However, when the fluid is sprayed in the direction of the arrow from the spray nozzle (300) as shown in Fig. 6, the powder (700) becomes flat and evenly distributed.

Thereby, the powder (700) with a high center is evenly spread out and flattened, and accordingly, there is an effect of being able to supply the powder (700) evenly.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by those skilled in the art within the scope of the technical idea of the present invention and the equivalent scope of the patent claims to be described below.

10: Powder supply device for dry electrode 100: Vacuum conveyor
110: Hopper 120: Powder conveyor
200: Powder cover part 210: Body part
220 : Opening 230 : Joining opening
300: Injection nozzle part 400: Base
500: Compressed air supply unit 600: Regulator
700 : Powder

Claims (10)

A vacuum conveyor equipped with a powder transport section through which powder for dry electrodes is transported;
A powder cover part coupled to the powder transport part of the vacuum conveyor and covering the powder;
A spray nozzle part that is coupled to the above powder cover part and sprays fluid; and
A powder supply device for a dry electrode including a support on which the powder is placed. In the first paragraph,
A powder supply device for a dry electrode, characterized in that the powder cover part is located on the upper side of the support, and the powder transport part is coupled to the upper side of the powder cover part. In the first paragraph,
The above powder cover part,
A body part formed such that the diameter increases from the top to the bottom; and
A powder supply device for a dry electrode, characterized in that it includes an opening formed on the upper side of the body part and to which the powder transport part is coupled. In the third paragraph,
A powder supply device for a dry electrode, characterized in that the body part is formed in a conical shape. In the first paragraph,
The above injection nozzle section is provided in multiple units,
A powder supply device for a dry electrode, characterized in that a plurality of the above-described injection nozzle sections are respectively connected to the above-described powder cover section at preset intervals. In paragraph 5,
The above-mentioned multiple injection nozzle sections are four in number,
A powder supply device for a dry electrode, characterized in that the four above-mentioned injection nozzle sections are each connected to the above-mentioned powder cover section at 90-degree intervals. In Article 6,
A powder supply device for a dry electrode, characterized in that the four injection nozzle sections are arranged to sequentially inject fluid in a clockwise or counterclockwise direction from any one of the injection nozzle sections. In Article 6,
A powder supply device for a dry electrode, characterized in that the above four injection nozzles are arranged to all inject fluid at once. In any one of claims 1 to 9,
A powder supply device for a dry electrode, characterized in that a compressed air supply unit is coupled to the above-mentioned injection nozzle unit, and compressed air provided from the compressed air supply unit is injected through the above-mentioned injection nozzle unit. In Article 9,
A powder supply device for a dry electrode, characterized in that it further includes a regulator that controls the pressure of compressed air provided from the compressed air supply unit.

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