Device for drying electrode

Abstract

According to an example embodiment, an apparatus for drying an electrode is provided. The device includes a plurality of light emitting devices arranged along a traveling direction of electrodes, each electrode including a plate and an active material, where each of the plurality of light emitting devices includes: a light source configured to generate light of an infrared band; and a reflector configured to reflect light generated by the light source, and a reflecting surface of the reflector is a paraboloid.

Description

Technical Field

[0001] The present invention relates to an electrode drying device. This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0029869 filed on March 7, 2023, and the entire contents of the Korean Patent Application are incorporated herein by reference. Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries have been widely used as energy sources for various types of wireless devices (e.g., mobile phones, laptops, and cordless vacuum cleaners). Recently, due to improved energy density and economies of scale, the manufacturing costs of electric hybrid electric vehicles (HEV) and battery electric vehicles (BEV) have been greatly reduced, and the cruising range of BEVs has been improved to the same level as the cruising range of fuel vehicles, and therefore, the main use of secondary batteries is shifting from mobile devices to transportation (mobility).

[0003] The electrode drying process is a process of removing moisture from the sheet-shaped positive electrode plate and the sheet-shaped negative electrode plate after the active material is applied to the sheet-shaped positive electrode plate and the sheet-shaped negative electrode plate, and before the sheet-shaped positive electrode plate and the sheet-shaped negative electrode plate are separated from each other. By uniformly drying all surfaces of the electrode sheet, the yield and reliability of the secondary battery can be improved. Summary of the invention

[0004] Technical issues

[0005] The present invention is directed to providing an electrode drying system having improved reliability.

[0006] Technical Solution

[0007] An embodiment of the present invention provides an electrode drying device. The electrode drying device includes a plurality of light emitting devices arranged along a moving direction of an electrode, wherein the electrode includes a plate and an active material, wherein each of the plurality of light emitting devices includes a light source configured to generate light in an infrared band and a reflector configured to reflect the light generated from the light source, and the reflective surface of the reflector is a parabola.

[0008] Each of the plurality of light emitting devices may be configured to emit parallel light.

[0009] The light source can be at the focus of the parabola.

[0010] An exemplary embodiment provides an electrode drying device, which includes a first light emitting device and a second light emitting device alternately arranged along a moving direction of an electrode including a plate and an active material. The first light emitting device may include a first light source configured to generate a first light in an infrared band and a first reflector configured to reflect the first light generated from the first light source, and the second light emitting device may include a second light source configured to generate a second light in an infrared band and a second reflector configured to reflect the second light generated from the second light source. A first reflective surface of the first reflector may be different from a second reflective surface of the second reflector.

[0011] The first reflecting surface may be a parabola.

[0012] The second reflecting surface may be a parabola.

[0013] The first focal length of the first reflective surface may be smaller than the second focal length of the second reflective surface.

[0014] The first light source may be at a focal point of the first reflective surface.

[0015] The second light source may be at a focal point of the second reflective surface.

[0016] The first light emitting device may be configured to emit parallel light.

[0017] The second light emitting device may be configured to emit non-parallel light.

[0018] The second light emitting device may include a third reflector configured to reflect the second light reflected by the second reflector.

[0019] The third reflecting surface of the third reflector may be a parabola.

[0020] The second light source may be at a focal point of the second reflective surface.

[0021] Example embodiments provide an electrode drying device including first and second light emitting devices alternately arranged along a moving direction of an electrode including a plate and an active material.

[0022] The first light emitting device may include a first light source configured to generate first light in an infrared band and a first reflector configured to reflect the first light generated from the first light source.

[0023] The second light emitting device may include a second light source configured to generate second light in an infrared band and a second reflector configured to reflect the second light generated from the second light source.

[0024] The first light emitting device may be configured to emit parallel light, and the second light emitting device may be configured to emit non-parallel light.

[0025] The first reflector may include a first reflecting surface that is a parabola.

[0026] The second reflector may include a second reflecting surface that is a parabola.

[0027] The first light source is spaced apart from a focal point of the first reflective surface.

[0028] The second light source may be at a focal point of the second reflective surface.

[0029] Beneficial Effects

[0030] According to an exemplary embodiment of the present invention, infrared rays can be emitted to an electrode using a reflector having a parabolic reflection surface. Therefore, electrode drying uniformity can be improved.

[0031] The effects that can be achieved by the exemplary embodiments of the present invention are not limited to the above effects, and those skilled in the art to which the exemplary embodiments of the present invention belong will clearly derive and understand other effects not described herein from the following description. That is, those skilled in the art can derive from the exemplary embodiments of the present invention the unexpected effects achieved when implementing the exemplary embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a diagram for describing an electrode drying device according to an example embodiment.

[0033] Figure 2 It is shown Figure 1 Figure 1. A diagram of a light emitting device.

[0034] Figure 3 are diagrams for describing light emitting devices according to other example embodiments.

[0035] Figure 4 are diagrams for describing light emitting devices according to other example embodiments.

[0036] Figure 5 are diagrams for describing light emitting devices according to other example embodiments.

[0037] Figure 6 are diagrams for describing light emitting devices according to other example embodiments.

[0038] Figure 7 is a diagram for describing an electrode drying device according to an example embodiment.

[0039] Figure 8 is a diagram for describing an electrode drying device according to an example embodiment. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before describing the embodiments of the present invention, the terms or expressions used in this specification and claims should not be interpreted as limited to the meanings defined in the commonly understood or commonly used dictionaries, but should be understood based on the meanings and concepts corresponding to the present invention, based on the inventor of the present application can appropriately define the terms or expressions to best explain the principle of the present invention.

[0041] Therefore, the embodiments described herein and the configurations shown in the drawings are merely examples of the present invention and do not reflect all technical ideas of the present invention, and therefore it should be understood that various equivalents and modifications of alternative configurations have been made on the filing date of the present application.

[0042] Well-known configurations or functions related to describing the present invention are not described in detail when it is determined that the subject matter of the present invention would be obscure due to unnecessary detail.

[0043] Because the embodiments of the present invention are provided to explain the present invention more comprehensively to those skilled in the art, the shapes, sizes, etc. of the components shown in the drawings may be exaggerated, omitted, or schematically shown for the sake of clarity. Therefore, the size or ratio of the components should not be understood to reflect their actual size or ratio at all.

[0044] (First Embodiment)

[0045] Figure 1 is a diagram for describing an electrode drying device 10 according to an example embodiment.

[0046] Figure 2 It is shown Figure 1 FIG. 1 is a diagram of a light emitting device 100 .

[0047] refer to Figure 1 and Figure 2 , the electrode drying device 10 may include a plurality of light emitting devices 100. The electrode drying device 10 may be configured to perform a drying process on the electrode EL. Here, the drying process is a process of emitting light IR in an infrared band to the upper surface ELU and the lower surface ELL of the electrode EL to remove moisture from the electrode EL. The electrode drying device 10 may perform a roll-to-roll drying process. The electrode EL unwound from the first roll R1 may be dried by the electrode drying device 10 and then wound around the second roll R2.

[0048] The electrode EL can be used to manufacture a secondary battery. The electrode EL can be a positive electrode or a negative electrode. The positive electrode includes a positive electrode plate and a positive electrode active material applied to the positive electrode plate, and the negative electrode includes a negative electrode plate and a negative electrode active material applied to the negative electrode plate.

[0049] Here, the electrode EL may be a positive electrode or a negative electrode of a secondary battery. The positive electrode includes a positive electrode plate and a positive electrode active material applied to the positive electrode plate. The negative electrode includes a negative electrode plate and a negative electrode active material applied to the negative electrode plate.

[0050] The thickness of the positive plate can be in the range of about 3 μm to about 500 μm. The positive plate does not cause chemical changes in the final manufactured secondary battery and can have high conductivity. The positive plate may include, for example, stainless steel, nickel, titanium, baked carbon and aluminum. The positive plate may include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the positive plate may include fine uneven structures to increase the adhesion of the active material. The positive plate may be in the form of a film, sheet, foil, mesh, pores, foam, non-woven fabric, etc.

[0051] The thickness of the negative plate can be in the range of about 3 μm to about 500 μm. The negative plate does not cause chemical changes in the final manufactured secondary battery and can have high conductivity. The negative plate may include copper, stainless steel, aluminum, nickel, titanium, baked carbon, and aluminum-cadmium alloy. The negative plate may include stainless steel surface-treated with carbon, nickel, titanium, silver, etc. The surface of the negative plate may include fine uneven structures to increase the adhesion of the active material. The negative plate may be in the form of a film, sheet, foil, mesh, pores, foam, non-woven fabric, etc.

[0052] The positive electrode active material is a material that can cause an electrochemical reaction. The positive electrode active material can be a lithium transition metal oxide. For example, the positive electrode active material may include: a layered compound substituted with one or more transition metals, such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2); a lithium manganese oxide substituted with one or more transition metals; a compound having the chemical formula LiNi 1-y M y Lithium nickel oxide represented by O2 (herein, M is Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn or Ga, and 0.01≤y≤0.7); 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A represents a lithium nickel cobalt manganese compound oxide, for example, Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2 or Li 1+zN i 0.4 Mn 0.4 Co 0.2O2 (where -0.5 ≤ z ≤ 0.5, 0.1 ≤ b ≤ 0.8, 0.1 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.2, 0 ≤ e ≤ 0.2, b + c + d < 1, M is Al, Mg, Cr, Ti, Si or Y, and A is F, P or Cl); or a lithium metal phosphate olivine represented by the chemical formula Li 1+x M 1-y M' y PO 4-z X z (where M is a transition metal, and more specifically, Fe, Mn, Co or Ni, M' is Al, Mg or Ti, X is F, S or N, -0.5 ≤ x ≤ +0.5, 0 ≤ y ≤ 0.5 and 0 ≤ z ≤ 0.1).

[0053] For example, the negative electrode active material may include, for example, carbon, such as non-graphitized carbon or graphitic carbon. The negative electrode active material may include, for example, metal composite oxides, such as, Li x Fe2O3 (0 ≤ x ≤ 1), LixWO2 (0 ≤ x ≤ 1) or Sn x Me 1-x Me' y O z (where Me is Mn, Fe, Pb or Ge, Me′ is Al, B, P, Si, an element of Group I, Group II or Group III of the periodic table, or a halogen, 0 < x ≤ 1, 1 ≤ y ≤ 3 and 1 ≤ z ≤ 8). The negative electrode active material may include, for example, lithium metal, lithium alloy, silicon-based alloy and tin-based alloy. The negative electrode active material may include, for example, metal oxides, such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4 or Bi2O5. The negative electrode active material may include, for example, conductive polymers, such as polyacetylene, lithium cobalt nickel-based materials, etc.).

[0054] Each of the plurality of light emitting devices 100 may be configured to emit light IR in the infrared band towards the electrode EL. The wavelength of the light IR generated by the plurality of light emitting devices 100 may be in the range from 0.78 μm to about 2.5 μm. Some of the plurality of light emitting devices 100 may be on the electrode EL and emit light IR towards the upper surface ELU of the electrode EL. Some of the plurality of light emitting devices 100 may be located below the electrode EL and emit light IR towards the lower surface EL of the electrode EL.

[0055] According to an exemplary embodiment, the light IR emitted from the plurality of light emitting devices 100 may be calibrated. Thus, the light IR may be parallel light and improve the uniformity when drying the electrode EL.

[0056] According to example embodiments, each of the plurality of light emitting devices 100 may include a light source 110 and a reflector 120. The light source 110 may be configured to generate light IR in an infrared band. The reflector 120 may include a reflective surface 120R having a high reflectivity and a low absorptivity with respect to the light IR. For example, the reflectivity of the reflective surface 120R with respect to the incident light IR may be about 95% or more. As another example, the reflectivity of the reflective surface 120R with respect to the incident light IR may be about 99% or more. As another example, the reflectivity of the reflective surface 120R with respect to the incident light IR may be about 99.9% or more.

[0057] According to example embodiments, the reflective surface 120R may be a parabola. According to example embodiments, the light source 110 may be at the focus of the reflective surface 120R. Therefore, the light IR generated from the light source 110 and reflected from the reflective surface 120R may be substantially parallel to the optical axis of the reflective surface 120R. Here, the optical axis is the rotational symmetry axis of the optical system and may be a straight line connecting the symmetry centers of the refractive surface or the reflective surface. That is, the light IR generated from the light source 110 and reflected from the reflective surface 120R may be parallel light.

[0058] (Second Embodiment)

[0059] Figure 3 is a diagram for describing a light emitting device 101 according to other example embodiments. Figure 3 The light emitting device 101 can replace the electrode drying device 10 Figure 2 A light emitting device 100.

[0060] refer to Figure 3 According to an example embodiment, the light emitting device 101 may include a light source 110 and a reflector 120. The light source 110 and the reflector 120 are substantially the same as those described above with reference to Figure 1 and Figure 2 Same as those described.

[0061] The light source 110 may not be at the focal point FP. According to an example embodiment, the light source 110 may be spaced apart from the focal point FP of the reflective surface 120R. According to an example embodiment, the light source 110 may be closer to the reflective surface 120R than the focal point FP. Therefore, the light IR generated from the light source 110 and reflected from the reflective surface 120R may be inclined with respect to the optical axis of the reflective surface 120R. That is, the light IR generated from the light source 110 and reflected from the reflective surface 120R may be non-parallel light. The light R generated from the light source 110 and reflected from the reflective surface 120R may be divergent light.

[0062] According to example embodiments, the light emitting device 101 emits divergent light, and thus the area of ​​the portion of the electrode EL covered by the light IR emitted by the light emitting device 101 increases. Therefore, the number of light emitting devices 101 required to perform a drying process may be reduced.

[0063] (Third Embodiment)

[0064] Figure 4 is a diagram for describing a light emitting device 102 according to other example embodiments. Figure 4 The light emitting device 102 can replace the electrode drying device 10 Figure 2 A light emitting device 100.

[0065] refer to Figure 4 According to an example embodiment, the light emitting device 102 may include a light source 110 and a reflector 121. The light source 110 is similar to the reflector 121 of the embodiment of the present invention. Figure 1 and Figure 2 The light sources described are essentially the same.

[0066] The reflector 122 may include a reflective surface 121R having high reflectivity and low absorptivity with respect to the light IR. For example, the reflectivity of the reflective surface 121R with respect to the incident light IR may be about 95% or more. As another example, the reflectivity of the reflective surface 121R with respect to the incident light IR may be about 99% or more. As another example, the reflectivity of the reflective surface 121R with respect to the incident light IR may be about 99.9% or more.

[0067] According to example embodiments, the reflective surface 121R may be a parabola. According to example embodiments, the light source 110 may be at a focus of the reflective surface 121R. Therefore, the light IR generated from the light source 110 and reflected from the reflective surface 121R may be substantially parallel to the optical axis of the reflective surface 121R.

[0068] refer to Figure 2 and Figure 4 , the focal length f2 of the reflective surface 121R can be greater than the focal length f1 of the reflective surface 120R. Therefore, a larger portion of the light IR generated from the light source 110 can be parallel light, and the energy efficiency of the light emitting device 102 emitting light can be improved. In addition, since the cross-sectional area of ​​the light IR emitted from the light emitting device 102 is reduced, the electrode EL (see Figure 1 ) can be used at a temperature higher than Figure 2 The light emitting device 100 increases at a higher rate, and the efficiency of the drying process can be improved.

[0069] (Fourth Embodiment)

[0070] Figure 5 is a diagram for describing a light emitting device 103 according to other example embodiments. Figure 5 The light emitting device 103 can replace the electrode drying device 10 Figure 2 A light emitting device 100.

[0071] refer to Figure 5 According to an example embodiment, the light emitting device 103 may include a light source 111 and a reflector 120. The reflector 120 is similar to the above-mentioned Figure 1 and Figure 2 The reflectors described are essentially the same.

[0072] According to example embodiments, the light source 111 may be a surface light source. The light IR generated from the light source 111 may be calibrated. According to example embodiments, the light source 111 may include a beam former for forming a cross section of the light IR.

[0073] The light source 111 may not be at the focal point FP. According to an example embodiment, the light source 111 may be spaced apart from the focal point FP of the reflective surface 120R. According to an example embodiment, the light source 111 may be farther from the reflective surface 120R than the focal point FP of the reflective surface 120R. According to an embodiment, the light source 111 may be spaced apart from the reflective surface 120R, and the focal point FP of the reflective surface 120R is located between the light source and the reflective surface. Therefore, interference between the light source 111 and the light IR reflected from the reflective surface 120R can be prevented.

[0074] According to example embodiments, the light IR generated from the light source 111 and reflected from the reflective surface 120R may be inclined relative to the optical axis of the reflective surface 120R. That is, the light IR generated from the light source 111 and reflected from the reflective surface 120R may be non-parallel light. The light IR generated from the light source 111 and reflected from the reflective surface 120R may be divergent light.

[0075] According to the example embodiment, the light emitting device 103 emits divergent light, and thus the area of ​​the portion of the electrode to be covered increases. Therefore, the electrode drying process can be performed using a relatively small number of light emitting devices 103.

[0076] (Fifth Embodiment)

[0077] Figure 6 is a diagram for describing a light emitting device 104 according to other example embodiments. Figure 6 The light emitting device 104 can replace the electrode drying device 10 Figure 2 A light emitting device 100.

[0078] refer to Figure 6 According to an example embodiment, the light emitting device 104 may include a light source 110, a first reflector 123, and a second reflector 125. The light source 110 is similar to the light source 110 described above. Figure 1 and Figure 2 The first reflector 123 and the second reflector 125 are substantially the same as those described above. Figure 1 and Figure 2 The reflectors 120 described are substantially the same. That is, the first reflector 123 may include a first reflective surface 123R that is a parabola, and the second reflector 125 may include a second reflective surface 125R that is a parabola.

[0079] According to an embodiment, the light source 110 may be at a focus of the first reflective surface 123R of the first reflector 123. Therefore, the light IR generated from the light source 110 may be reflected and collimated by the first reflector 123. The light IR collimated by the first reflector 123 may be reflected by the second reflector 125. The light IR reflected by the second reflector 125 may be non-parallel light. The light IR reflected by the second reflector 125 may be divergent light.

[0080] According to the example embodiment, the light emitting device 104 emits divergent light, and thus the area of ​​the portion of the electrode to be covered increases. Therefore, the number of light emitting devices 104 required to perform the drying process can be reduced.

[0081] (Sixth Embodiment)

[0082] Figure 7 is a diagram for describing an electrode drying device 11 according to an example embodiment.

[0083] refer to Figure 7 , the electrode drying device 11 may be configured to perform a drying process of the electrode EL. The electrode drying device 11 may include a first light emitting device 100a and a second light emitting device 100b. According to example embodiments, the first light emitting device 100a and the second light emitting device 100b may be alternately arranged. Therefore, the second light emitting device 100b may be inserted between the first light emitting devices 100a, and the first light emitting device 100a may be inserted between the second light emitting devices 100b.

[0084] According to example embodiments, the first light emitting device 100a may be different from the second light emitting device 100b. Each of the first light emitting devices 100a may be Figures 2 to 6 One of the light emitting devices 100, 101, 102, 103 and 104, and each of the second light emitting devices 100b may be Figures 2 to 6 For example, each of the first light emitting devices 100a may be Figure 2 The light emitting device 100 of the embodiment of the present invention, and each of the second light emitting devices 100b may be Figure 3 A light emitting device 101 is provided.

[0085] (Seventh Embodiment)

[0086] Figure 8 is a diagram for describing an electrode drying device 12 according to an example embodiment.

[0087] refer to Figure 8 The electrode drying device 12 may be configured to perform a drying process of the electrode EL. The electrode drying device 12 may include first to fourth light emitting devices 100a, 100b, 100c, and 100d. The first to fourth light emitting devices 100a, 100b, 100c, and 100d may be arranged along the moving direction of the electrode EL.

[0088] According to example embodiments, each of the first to fourth light emitting devices 100a, 100b, 100c, and 100d may be Figures 2 to 6 One of the light emitting devices 100, 101, 102, 103 and 104.

[0089] According to example embodiments, the first to fourth light emitting devices 100a, 100b, 100c, and 100d may be different from each other. For example, each of the first light emitting device 100a may be Figure 2 The light emitting device 100, each of the second light emitting devices 100b may be Figure 3 The light emitting device 101, each of the third light emitting devices 100c may be Figure 4 The light emitting device 102, and each of the fourth light emitting devices 100d may be Figure 5 Light emitting device 103.

[0090] According to example embodiments, some of the first to fourth light emitting devices 100a, 100b, 100c, and 100d may be the same. For example, each of the first light emitting devices 100a may be Figure 2 The light emitting device 100, each of the second light emitting devices 100b may be Figure 2 The light emitting device 100, each of the third light emitting devices 100c may be Figure 3 The light emitting device 101, and each of the fourth light emitting devices 100d may be Figure 4 A light emitting device 102 is provided.

[0091] The present invention is described in more detail above with reference to the accompanying drawings, embodiments, etc. However, the configurations shown in the drawings or embodiments described in this specification are merely embodiments of the present invention and do not reflect all technical ideas of the present invention, and therefore it should be understood that various equivalents and modifications of alternative configurations have been made on the filing date of this application.

Claims

1. An electrode drying device, comprising a plurality of light emitting devices arranged along a moving direction of an electrode, wherein the electrode comprises an electrode plate and an active material, wherein: Each of the plurality of light emitting devices comprises: a light source configured to generate light in an infrared band; and a reflector configured to reflect light generated from the light source, Wherein, the reflecting surface of the reflector is a parabola.

2. The electrode drying device according to claim 1, wherein: Each of the plurality of light emitting devices is configured to emit parallel light.

3. The electrode drying device according to claim 1, wherein: The light source is at the focus of the parabola.

4. An electrode drying device, comprising a first light emitting device and a second light emitting device arranged alternately along a moving direction of an electrode, wherein the electrode comprises an electrode plate and an active material, wherein: The first light emitting device comprises: A first light source configured to generate first light in an infrared band; and a first reflector configured to reflect the first light generated from the first light source; The second light emitting device comprises: A second light source configured to generate a second light in an infrared band; and a second reflector configured to reflect the second light generated from the second light source, and The first reflective surface of the first reflector is different from the second reflective surface of the second reflector.

5. The electrode drying device according to claim 4, wherein: The first reflecting surface is a parabola.

6. The electrode drying device according to claim 5, wherein: The second reflecting surface is a parabola.

7. The electrode drying device according to claim 6, wherein: A first focal length of the first reflective surface is smaller than a second focal length of the second reflective surface.

8. The electrode drying device according to claim 7, wherein: The first light source is located at a focal point of the first reflecting surface, and The second light source is located at a focal point of the second reflecting surface.

9. The electrode drying device according to claim 4, wherein: The first light emitting device is configured to emit parallel light, and The second light emitting device is configured to emit non-parallel light.

10. The electrode drying device according to claim 4, wherein: The second light emitting device comprises: A third reflector is configured to reflect the second light reflected by the second reflector.

11. The electrode drying device according to claim 10, wherein: The third reflecting surface of the third reflector is a parabola.

12. The electrode drying device according to claim 10, wherein: The second light source is at a focal point of the second reflective surface.

13. An electrode drying device, comprising a first light emitting device and a second light emitting device arranged alternately along a moving direction of an electrode, wherein the electrode comprises an electrode plate and an active material, wherein: The first light emitting device comprises: A first light source configured to generate first light in an infrared band; and a first reflector configured to reflect the first light generated from the first light source, The second light emitting device comprises: A second light source configured to generate a second light in an infrared band; and a second reflector configured to reflect the second light generated from the second light source, and The first light emitting device is configured to emit parallel light, and the second light emitting device is configured to emit non-parallel light.

14. The electrode drying device according to claim 13, wherein: The first reflector comprises a first reflecting surface, the first reflecting surface is a parabola, The second reflector includes a second reflecting surface, the second reflecting surface is a parabola, and The first light source is spaced apart from a focal point of the first reflective surface.

15. The electrode drying device according to claim 14, wherein: The second light source is at a focal point of the second reflective surface.

Images