Drying device
The drying device addresses energy inefficiency by recycling heated air with solvent vapor, reducing energy use and preventing binder migration, while maintaining uniform heating.
Patent Information
- Application Number
- JP2024061615
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-05
- Publication Date
- 2025-10-17
AI Technical Summary
Conventional drying devices for electrode sheets consume excessive energy in heating outside air for preheating, which is inefficient and wasteful.
A drying device with a preheating unit that uses a circulation circuit to heat and humidify air with solvent vapor, reducing the need to heat outside air, and includes a preheating chamber filled with saturated vapor to preheat the electrode sheet.
Reduces energy consumption by reusing heated air, maintains moisture balance, and prevents migration of binder in the electrode paste, ensuring uniform heating.
Smart Images
Figure 2025158755000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a drying device. [Background technology]
[0002] For example, Japanese Patent Laid-Open Publication No. 2002-008722 (Patent Document 1) discloses a drying device for drying an electrode sheet on which an electrode paste has been formed. The drying device generally dries the electrode paste by blowing heated air onto the electrode sheet to form an electrode mixture layer. In such a drying device, air taken in from the outside is heated, and the heated air is blown onto the electrode sheet. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-008722 Summary of the Invention [Problem to be solved by the invention]
[0004] In the electrode sheet drying device, in the first preheating section, the electrode sheet is heated to, for example, 120° C. The purpose of this preheating section is to warm the electrode sheet itself, and not to remove moisture from the electrode paste.
[0005] On the other hand, in conventional drying devices, even in the preheating section, air taken in from outside is heated and blown onto the electrode sheets, and then the air that has warmed the electrode sheets is discharged to the outside.
[0006] This in turn necessitates heating the outside air, which poses a problem in that a lot of energy is used to heat the air.
[0007] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a drying device that reduces the amount of energy used to heat air in the preheating section. [Means for solving the problem]
[0008] A drying device according to a first aspect of the present disclosure is a drying device that dries an electrode sheet on which an electrode paste has been formed, and includes a preheating unit that preheats the electrode sheet, and a drying unit that dries the electrode paste formed on the electrode sheet preheated in the preheating unit, wherein the preheating unit is formed from a heating section, a liquid supply section, and a spraying section, and includes a circulation circuit in which gas circulates, the heating section heats the gas, and the liquid supply section supplies liquid to the gas.
[0009] The gas in the drying device according to the first aspect of the present disclosure is air, and the liquid is water.
[0010] The liquid in the drying device according to the first aspect of the present disclosure is a solvent contained in the electrode paste.
[0011] The liquid supply unit of the drying device according to the first aspect of the present disclosure is disposed upstream of the gas flowing in the circulation circuit with respect to the heating unit.
[0012] A preheating unit of a drying device according to a first aspect of the present disclosure is formed with a preheating chamber, a spraying unit is provided in the preheating chamber, an electrode sheet is placed in the preheating chamber, and the spraying unit sprays gas onto the electrode sheet in an environment in which the preheating chamber is filled with saturated vapor of liquid. [Effects of the Invention]
[0013] According to the drying device of the present disclosure, the amount of energy used to heat the air in the preheating section can be reduced. [Brief explanation of the drawings]
[0014] [Figure 1] FIG. 2 is a schematic diagram of a manufacturing apparatus according to the present embodiment. [Figure 2] FIG. 2 is a schematic diagram of an electrode sheet. [Figure 3] FIG. 2 is a schematic diagram of a preheating unit. [Figure 4] FIG. 2 is a schematic diagram of a drying unit. DETAILED DESCRIPTION OF THE INVENTION
[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.
[0016] 1 is a diagram showing the configuration of a manufacturing apparatus according to this embodiment. The manufacturing apparatus 1 manufactures an electrode sheet 2 shown in FIG.
[0017] The electrode sheet 2 is produced by applying an electrode paste 3 to a metal foil 4. The electrode paste 3 contains an active material, a binder, and a solvent. A plurality of electrode pastes 3 are arranged side by side on the surface of the metal foil 4 along the conveyance direction L. The electrode sheet 2 is used, for example, in an in-vehicle lithium-ion battery.
[0018] Referring again to FIG. 1, the manufacturing apparatus 1 includes a coating device 5, a conveying device 6, and a drying device .
[0019] The coating device 5 coats the electrode paste 3 on the surface of the metal foil 4. The transport device 6 includes a first roll unit 8, a second roll unit 9, and a winding unit 10. The first roll unit 8, the second roll unit 9, and the winding unit 10 are configured to be rotatable in a rotation direction R. The transport device 6 transports the metal foil 4 in a transport direction L.
[0020] The first roll unit 8 is provided upstream of the drying device 7 in the conveying direction L of the electrode sheet 2. The second roll unit 9 is provided downstream of the drying device 7 in the conveying direction L of the electrode sheet 2. The coating device 5 coats the metal foil 4 of the electrode sheet 2 that passes through the first roll unit 8 with electrode paste 3. The winding unit 10 rotates in the rotation direction R to wind up the electrode sheet 2 that has come out of the drying device 7. The rotation of the winding unit 10 also feeds the electrode sheet 2 in the conveying direction L of the electrode sheet 2 in the manufacturing apparatus 1.
[0021] The drying device 7 dries the electrode sheet 2 transported by the conveying device 6. The drying device 7 includes a preheating unit 11 and at least one drying unit 12. The drying device 7 also includes an outer shell 28. The outer shell 28 has a preheating case 35 and a heating case 36.
[0022] The outer shell 28 is formed by an end wall 29, an end wall 30, and a peripheral wall 31. The end wall 29, the end wall 30, and the peripheral wall 31 form a transfer chamber 34.
[0023] The end walls 29 and 30 are each arranged in the conveying direction L. The end walls 29 and 30 are formed with openings 29a and 30a, respectively. The electrode sheet 2 is carried into the conveying chamber 34 through the opening 29a and carried out from the conveying chamber 34 through the opening 30a. The peripheral wall 31 is formed to connect the outer peripheral edge of the end wall 29 and the outer peripheral edge of the end wall 30.
[0024] The preheating case 35 is formed by an end wall 29, a portion of the peripheral wall 31, and a partition wall 22. The partition wall 22 is disposed between the end wall 29 and the end wall 30. The end wall 29, the partition wall 22, and the end wall 30 are disposed so as to be aligned in the conveying direction L. The partition wall 22 has an opening 22a formed therein to allow the electrode sheet 2 to pass through. A preheating chamber 13 is formed inside the preheating case 35.
[0025] The heating case 36 is formed by the partition wall 22, a part of the peripheral wall 31, and the end wall 30. Inside the heating case 36, a drying chamber 15 is formed.
[0026] The preheating chamber 13 is arranged to be aligned with the drying chamber 15 in the conveying direction L. The preheating chamber 13 is located upstream of the drying chamber 15 in the conveying direction L. The preheating chamber 13 is provided with a blowing unit 14. The electrode sheet 2 carried into the preheating chamber 13 is preheated by gas blown from the blowing unit 14. In the preheating chamber 13, the area where the electrode sheet 2 is preheated is called the preheating section. The gas is, for example, air.
[0027] The drying chamber 15 is located downstream of the preheating chamber 13 in the conveying direction L. The drying chamber 15 is provided with a blowing unit 16 and a heater 37. The electrode sheet 2 carried into the drying chamber 15 is dried by the gas blown from the blowing unit 16 and is also heated by the heater 37. The heater 37 is a heating device that uses, for example, IR light, laser light, Joule heat, or the like as a heat source. In the drying chamber 15, the region where the electrode sheet 2 is dried is called the drying section. The gas is, for example, air.
[0028] The heating case 36 may further be provided with a partition plate 32. The partition plate 32 is arranged between the partition wall 22 and the end wall 30. The partition wall 22, the partition plate 32, and the end wall 30 are arranged to be aligned in the conveying direction L. The partition plate 32 has an opening 32a formed therein so that the electrode sheet 2 can pass through. The partition plate 32 defines the drying chamber 15 into a plurality of spaces. A blowing unit 16 is provided in each of the spaces defined by the partition plate 32. Note that the drying chamber 15 may not be provided with the partition plate 32 and may instead form a single space as a whole.
[0029] 3 is a schematic diagram of the preheating unit 11. The preheating unit 11 will be described in detail with reference to FIG.
[0030] The preheating unit 11 includes a preheating case 35, a pipe 18, a blower 19, a heating section 20, a liquid supply section 21, a spray section 14, and a steam trap 38.
[0031] Piping 18 sequentially connects preheating case 35, blower 19, heating unit 20, liquid supply unit 21, and spray unit 14. Blower 19 sends gas in preheating chamber 13 in blowing direction D and supplies it to heating unit 20. Heating unit 20 heats the gas sent from blower 19.
[0032] Liquid supply unit 21 supplies mist-like liquid to the gas heated by heating unit 20. The gas that has passed through liquid supply unit 21 is sprayed onto electrode sheet 2 by spray unit 14 in preheating chamber 13 again.
[0033] The liquid is, for example, water. Using water makes it easy to handle. Furthermore, the liquid may be a solvent contained in the electrode paste 3. Specific examples of the solvent include organic solvents such as N-methylpyrrolidin, dimethylformamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethylenetriamine, N,N-dimethylaminopropylamine, ethylene oxide, and tetrahydrofuran.
[0034] The liquid supply unit 21 may be disposed upstream of the heating unit 20 in the air blowing direction D.
[0035] The steam trap 38 is provided in the preheating case 35 and discharges water droplets generated in the preheating chamber 13 to the outside. The steam trap 38 may be provided in the piping 18.
[0036] The circuit formed by the preheating case 35, the piping 18, the blower 19, the heating unit 20, the liquid supply unit 21, and the spraying unit 14 is called a circulation circuit 17. Within the circulation circuit 17, gas is circulated using the blower 19 as power.
[0037] 4 is a schematic diagram of the drying unit 12. The drying unit 12 will be described in detail with reference to FIG.
[0038] The drying unit 12 is formed by a part of the heating case 36, a partition plate 32 not shown in Fig. 4, a heater 37, piping 25, a blower 26, a heating section 27, a blowing section 16, and a discharge valve 39. A drying unit 12 is formed for each of the spaces of the drying chamber 15 defined by the partition plate 32.
[0039] The piping 25 sequentially connects the air blower 26, the heating unit 27, and the blowing unit 16. The air blower 26 sends gas taken in from the outside in the air blowing direction D to the heating unit 27. The heating unit 27 heats the gas sent from the air blower 26. The gas that has passed through the heating unit 27 is blown onto the electrode sheet 2 by the blowing unit 16 in the drying chamber 15. The gas is then exhausted to the outside from an exhaust valve 39 provided in the drying chamber 15.
[0040] The path formed by the blower 26, the heating unit 27, and the blowing unit 16, which are connected by the piping 25, is called the air blowing path 24. In the air blowing path 24, gas is sent to the blowing unit 16 using the blower 26 as power.
[0041] In the above embodiment, as shown in Fig. 3, the gas circulates in the circulation circuit 17. More specifically, the gas is heated in the heating unit 20, for example, to 120°C, and then a mist of liquid is supplied in the liquid supply unit 21. As a result, the gas becomes saturated vapor, and is sprayed by the spray unit 14 onto the electrode sheet 2 placed in the preheating chamber 13. The gas then preheats the electrode sheet 2. The gas in the preheating chamber 13 is then recovered by the blower 19, heated again, and supplied with liquid, and used to preheat the electrode sheet 2. The gas in the circulation circuit 17 repeats this cycle.
[0042] In this configuration, the electrode sheet 2 is preheated in the preheating chamber 13 of the manufacturing apparatus 1. The preheating unit 11 reheats the gas in the preheating chamber 13, which is at a higher temperature than the outside air, and therefore the amount of energy required to heat the gas can be reduced compared to when heating gas newly taken in from the outside air.
[0043] In the above embodiment, the gas that has been converted into a saturated vapor state through the liquid supply unit 21 flows into the preheating chamber 13. As a result, the inside of the preheating chamber 13 becomes an environment filled with saturated vapor.
[0044] As a result, it is possible to suppress the loss of moisture from the electrode paste 3 of the electrode sheet 2 placed in the preheating chamber 13. This in turn suppresses the occurrence of so-called migration, which is the upward segregation of the binder contained in the electrode paste 3. Additionally, by suppressing the energy consumed in vaporizing the solvent that forms the electrode paste 3, it is possible to suppress the amount of energy consumed other than for raising the temperature of the electrode sheet 2.
[0045] Since saturated steam gives off latent heat when it comes into contact with the electrode sheet 2, heating using saturated steam has a superior heat transfer coefficient compared to heating using gas that is not yet saturated, and can raise the temperature of the electrode sheet 2 uniformly.
[0046] In the above embodiment, the partition wall 22 is provided, which makes it possible to prevent saturated steam in the preheating chamber 13 from flowing into the drying chamber 15.
[0047] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]
[0048] 1 Manufacturing equipment, 2 Electrode sheet, 3 Electrode paste, 4 Metal foil, 5 Coating device, 6 Conveying device, 7 Drying device, 8 First roll section, 9 Second roll section, 10 Winding section, 11 Preheating unit, 12 Drying unit, 13 Preheating chamber, 14 Spraying section, 15 Drying chamber, 16 Spraying section, 17 Circulation circuit, 18 Piping, 19 Blower, 20 Heating section, 21 Liquid supply section, 22 Partition wall, 22a Opening, 24 Air flow path, 25 Piping, 26 Blower, 27 Heating section, 28 Outer shell, 29 End wall, 29a Opening, 30 End wall, 30a Opening, 31 Peripheral wall, 32 Partition plate, 32a Opening, 34 Conveying chamber, 35 Preheating case, 36 Heating case, 37 Heater, 38 Steam trap, 39 Discharge valve.
Claims
1. A drying device for drying an electrode sheet on which an electrode paste is formed, a preheating unit that preheats the electrode sheet; a drying unit that dries the electrode paste formed on the electrode sheet preheated in the preheating unit, the preheating unit is formed by a heating section, a liquid supply section, and a spray section, and includes a circulation circuit in which gas circulates; The heating unit heats the gas, The liquid supply unit supplies liquid to the gas.
2. the gas is air, The drying device of claim 1 , wherein the liquid is water.
3. The drying device according to claim 1 , wherein the liquid is a solvent contained in the electrode paste.
4. The drying device according to claim 1 , wherein the liquid supply unit is disposed upstream of the gas flowing in the circulation circuit with respect to the heating unit.
5. The preheating unit has a preheating chamber formed therein, The spray unit is provided in the preheating chamber, The electrode sheet is placed in a preheating chamber, The drying device according to claim 1 , wherein the spraying unit sprays the gas onto the electrode sheet in an environment where the preheating chamber is filled with saturated vapor of the liquid.
Citation Information
Patent Citations
Manufacturing method for nonaqueous electrolyte secondary battery having polymer electrolyte
JP2002008722A