Electrode surface treatment apparatus and electrode coating system including the same

Abstract

An electrode surface treatment apparatus according to an embodiment of the present disclosure includes: a guide roller configured to contact an electrode foil moving in a longitudinal direction and to support the electrode foil so as to guide a movement of the electrode foil; and a plasma unit configured to perform surface treatment on the electrode foil by spraying plasma onto the electrode foil while the electrode foil moves.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2022-0178976 filed in Korea on December 20, 2022, and Korean Patent Application No. 10-2023-0028739 filed in Korea on March 3, 2023, the disclosures of which are incorporated herein by reference.

[0002] The present disclosure relates to an electrode surface treatment device and an electrode coating system including the electrode surface treatment device, and more particularly, to an electrode surface treatment device for performing surface treatment on an electrode foil to which a coating material containing an electrode active material is to be applied and an electrode coating system including the electrode surface treatment device. Background Art

[0003] Generally, a secondary battery refers to a battery that can be repeatedly charged and discharged, such as a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, etc. These secondary batteries are manufactured by housing an electrode assembly including a positive electrode and a negative electrode stacked with a separator therebetween and an electrolyte material in a case of various shapes and sealing the case.

[0004] Electrodes of secondary batteries, such as positive electrodes or negative electrodes, can be divided into wet electrodes or dry electrodes according to their manufacturing methods. Wet electrodes are manufactured by applying a slurry-state electrode mixture containing a solvent to the surface of an electrode foil corresponding to a current collector to form a coating, and then drying the coating. On the other hand, dry electrodes are manufactured by pressing a solid electrode mixture that does not contain a solvent onto the surface of an electrode foil to form a coating.

[0005] Recently, considering the problems that the solvent contained in the electrode mixture of the wet electrode generates harmful gases during the drying process and wrinkles, pinholes and cracks are generated in the coating of the wet electrode after the solvent is dried, research and development on the technology of manufacturing dry electrodes that can replace wet electrodes has gradually increased.

[0006] However, it is difficult to attach the electrode mixture due to the presence of foreign matter such as rolling oil on the surface of the electrode foil corresponding to the electrode current collector. This problem is more serious in attaching a dry electrode of a solid state electrode mixture than in attaching a wet electrode of a slurry state electrode mixture.

[0007] Furthermore, in order to increase adhesion of the electrode foil, in the prior art, the electrode foil is cleaned and then a primer including a conductive material and an adhesive is coated on the entire surface or a portion of the surface of the electrode foil, so that manufacturing the electrode foil requires more time and cost. Summary of the invention

[0008] Technical issues

[0009] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to provide an electrode surface treatment device capable of improving electrode quality by enhancing adhesion between an electrode foil and an electrode mixture, and an electrode coating system including the electrode surface treatment device.

[0010] The present disclosure also provides an electrode surface treatment device capable of shortening the manufacturing time and reducing the manufacturing cost of an electrode while increasing the capacitance and energy density of the electrode, and an electrode coating system including the electrode surface treatment device.

[0011] Technical Solution

[0012] According to one aspect of the present disclosure, an electrode surface treatment device is provided, comprising: a guide roller configured to contact an electrode foil moving in a longitudinal direction (Machine Direction) and support the electrode foil, thereby guiding the movement of the electrode foil; and a plasma unit configured to perform surface treatment on the electrode foil by spraying plasma onto the electrode foil while the electrode foil moves.

[0013] In one embodiment, the plasma unit may be configured to spray plasma onto a portion of the electrode foil that contacts and is supported by the guide roller.

[0014] In one embodiment, a plurality of plasma units may be provided, and the plurality of plasma units may be configured to be arranged along a transverse direction and respectively spray plasma onto the electrode foil.

[0015] In one embodiment, a plurality of guide rollers may be provided, and the plurality of guide rollers may include: a first guide roller that contacts the lower surface of the upper surface and the lower surface of the electrode foil and supports the electrode foil; and a second guide roller that contacts the upper surface of the electrode foil and supports the electrode foil.

[0016] In one embodiment, a plurality of plasma units may be provided, and the plurality of plasma units may include: at least one first plasma unit that sprays plasma onto a first portion of the electrode foil that is in contact with and supported by the first guide roller; and at least one second plasma unit that sprays plasma onto a second portion of the electrode foil that is in contact with and supported by the second guide roller.

[0017] In one embodiment, the guide roller may have a hollow portion therein, and the plasma unit may be disposed within the hollow portion of the guide roller.

[0018] In one embodiment, the guide roller may have a through hole provided on an outer surface of the guide roller to communicate with the hollow portion, and the plasma unit may be configured to spray plasma onto the surface of the electrode foil through the through hole.

[0019] In one embodiment, the through hole may be configured in the form of a long hole or a slit extending in a transverse direction and having a predetermined width.

[0020] In one embodiment, an extension length of the through hole extending along the transverse direction may be smaller than a width of the electrode foil.

[0021] In one embodiment, a plurality of guide rollers and a plurality of plasma units may be provided, and at least one first plasma unit among the plurality of plasma units may be provided in a hollow portion of a first guide roller among the plurality of guide rollers, and at least one second plasma unit among the plurality of plasma units may be provided in a hollow portion of a second guide roller among the plurality of guide rollers.

[0022] In one embodiment, the electrode surface treatment device may further include an unwinder configured to unwind the electrode foil wound into a roll to move in the first direction, and the guide roller may be configured to guide the electrode foil moved by the unwinder.

[0023] In one embodiment, the electrode foil may be made of a material including aluminum.

[0024] An electrode coating system according to another aspect of the present disclosure includes: the electrode surface treatment device according to any one of the above embodiments; and a coating device configured to form a coating on a surface of the electrode foil surface-treated by the electrode surface treatment device.

[0025] Beneficial Effects

[0026] According to the present disclosure, the surface energy of the electrode foil is increased by performing surface treatment on the electrode foil using plasma to enhance adhesion between the electrode foil and the electrode mixture, and as a result, the electrode quality can be improved.

[0027] Furthermore, among the electrode active material and the binder included in the electrode mixture, the amount of the binder added for attachment to the electrode foil is reduced, and the amount of the electrode active material will increase in proportion to the reduced amount of the binder, thereby increasing the capacity and energy density of the electrode.

[0028] In addition, since there is no need to use an expensive primer foil to increase the adhesion of the electrode foil, the manufacturing time and cost of the electrode can be shortened.

[0029] Furthermore, since the surface treatment using plasma is performed during the conveyance of the electrode foil, there is no need to prepare a separate plasma treatment space, and the continuity of the dry manufacturing process can be ensured and the manufacturing time can be further shortened.

[0030] Furthermore, plasma is sprayed to a portion of the electrode foil that contacts and is supported by the guide roller, thereby preventing deformation or damage of the electrode foil such as wrinkles or wrinkles due to spray pressure of plasma and improving yield of good products.

[0031] Furthermore, since the electrode surface treatment device according to the present disclosure performs surface treatment of the electrode foil before the coating process of the electrode foil, it is independent of the electrode coating method and can be applied to both dry electrode manufacturing processes and wet electrode manufacturing processes, thereby improving electrode quality.

[0032] In addition, those skilled in the art to which the present disclosure pertains can clearly understand from the following description that various embodiments according to the present disclosure can solve various technical problems not mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a view illustrating an electrode surface treatment device according to an embodiment of the present disclosure.

[0034] Figure 2 It is a view illustrating an electrode surface treatment device according to a modified embodiment of the present disclosure.

[0035] Figure 3 is a view illustrating an electrode surface treatment device according to another modified embodiment of the present disclosure.

[0036] Figure 4 yes Figure 3 A view of the guide rollers of the electrode surface treatment device shown in FIG.

[0037] Figure 5 is along Figure 4 A cross-sectional view of the guide roller taken along line S1 - S1 ′ in FIG.

[0038] Figure 6 and Figure 7 is a view illustrating a surface treatment effect of the electrode surface treatment device according to the present disclosure.

[0039] Figure 8is a block diagram illustrating an electrode coating system according to an embodiment of the present disclosure.

[0040] Fig. 9 is a view illustrating an electrode coating system according to an embodiment of the present disclosure.

[0041] Fig.10 is a view illustrating an electrode coating system according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings to clarify the solutions to the technical problems of the present disclosure. However, when describing the present disclosure, the description of related known technologies that may obscure the subject matter of the present disclosure may be omitted. In addition, the terms used in this application are defined in consideration of the role in the present disclosure and may vary according to the intentions of designers, manufacturers, etc. or their habits. Therefore, the terms described below should be defined based on the description of the entire present application.

[0043] Figure 1 An electrode surface treatment device 100 according to an embodiment of the present disclosure is shown.

[0044] like Figure 1 As shown in , an electrode surface treatment device 100 according to an embodiment of the present disclosure may include an unwinder 110 , a guide roller 120 , and a plasma unit 130 .

[0045] The unwinder 110 is configured to unwind the rolled electrode foil E to move along the length direction, i.e., the longitudinal direction (Machine Direction) of the electrode foil E. The electrode foil E corresponds to a current collector of an electrode and may be made of any material as long as it has high conductivity and does not cause chemical changes in a secondary battery.

[0046] For example, the electrode foil E may be made of stainless steel; aluminum; nickel; titanium; calcined carbon; copper; or aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, silver, etc.

[0047] In particular, in the case where the electrode foil E corresponds to a current collector of a positive electrode, the electrode foil E may be made of a material including aluminum. The electrode foil E may have a thickness ranging from 8 μm to 20 μm.

[0048] The guide roller 120 is configured to come into contact with the electrode foil E moving in the longitudinal direction and to support the electrode foil E, thereby guiding the movement of the electrode foil E.

[0049] In one embodiment, a plurality of guide rollers 120 may be provided. For example, the guide rollers 120 may include a first guide roller 120A that contacts the lower surface of the upper surface and the lower surface of the electrode foil E and supports the electrode foil E, and a second guide roller 120B that contacts the upper surface of the electrode foil E and supports the electrode foil E.

[0050] The plasma unit 130 is configured to spray plasma onto the surface of the electrode foil E while the electrode foil E moves, thereby performing surface treatment on the electrode foil E. To this end, the plasma unit 130 may include an electrode that generates a high-voltage arc to generate plasma, a gas inlet that provides a gas between the electrodes, a nozzle that sprays plasma, etc. The plasma unit 130 may be supported by a support structure 132.

[0051] The plasma ejected from the plasma unit 130 is a collection of particles including negatively charged electrons and positively charged ions. Such plasma has a relatively high charge separation and has the same number of positive and negative charges as a whole, thereby maintaining an electrically neutral state.

[0052] In one embodiment, the electrode surface treatment device 100 may include a plurality of plasma units 130. In this case, the plurality of plasma units may be arranged along the longitudinal direction (Machine Direction), that is, the length direction of the electrode foil E, or along the transverse direction (Transverse Direction), that is, the width direction of the electrode foil E, or along both the longitudinal direction and the transverse direction, and plasma may be sprayed onto the surface of the electrode foil E.

[0053] Generally, foreign matter such as rolling oil remains on the surface of the electrode foil E manufactured by the rolling process. Therefore, the electrode surface treatment device according to the present disclosure can perform surface treatment on the electrode foil E using plasma to remove foreign matter such as rolling oil remaining on the surface of the electrode foil E and increase the surface energy of the electrode foil E.

[0054] As will be described again below, the surface-treated electrode foil E' may be transferred to a coating device (not shown) configured to form a coating layer including an electrode active material on the surface of the electrode foil E'.

[0055] Figure 2 1 is a view illustrating an electrode surface treatment device 100A according to a modified embodiment of the present disclosure.

[0056] like Figure 2 As shown in Figure 1The electrode surface treatment device 100A according to a modified embodiment of the present disclosure includes an unwinder 110, a guide roller 120, and a plasma unit 130. The electrode surface treatment device 100A is similar to the electrode surface treatment device 100 shown in FIG. Figure 1 The electrode surface treatment device 100 shown in FIG. 1 is different in the arrangement of the plasma unit 130 and the plasma spraying method.

[0057] That is to say, if we refer to Figure 1 As described above, the unwinder 110 is configured to unwind the electrode foil E wound into a roll so as to move along the longitudinal direction (machine direction), that is, the length direction of the electrode foil E.

[0058] The guide roller 120 is configured to come into contact with the electrode foil E moving in the longitudinal direction and to support the electrode foil E, thereby guiding the movement of the electrode foil E.

[0059] The plasma unit 130 is configured to continuously spray plasma onto the surface of the electrode foil E while the electrode foil E moves, thereby performing surface treatment on the electrode foil E. The plasma unit 130 may be supported by a support structure 132 .

[0060] In particular, with Figure 1 Unlike the electrode surface treatment apparatus 100 in FIG. 1 , the plasma unit 130 of the electrode surface treatment apparatus 100A may be configured to spray plasma onto a portion of the electrode foil E that contacts and is supported by the guide roller 120 , thereby performing surface treatment.

[0061] As a result, the tension of the electrode foil E can be maintained while the plasma is ejected, thereby preventing deformation or damage of the electrode foil such as wrinkles, wrinkles, etc. caused by the ejection pressure of the plasma and improving the yield of good products.

[0062] In one embodiment, the electrode surface treatment device 100A may include a plurality of plasma units 130. In this case, the plurality of plasma units may be arranged in a transverse direction, that is, a width direction of the electrode foil E, to spray plasma over the entire width of the electrode foil E.

[0063] In addition, in one embodiment, the electrode surface treatment device 100A may include a plurality of guide rollers 120. In this case, the plurality of guide rollers may include a first guide roller 120A that contacts the lower surface of the upper surface and the lower surface of the electrode foil E and supports the electrode foil E, and a second guide roller 120B that contacts the upper surface of the electrode foil E and supports the electrode foil E.

[0064] In this case, the plurality of plasma units 130 may include: at least one first plasma unit 130A that sprays plasma onto a first portion of the electrode foil E that contacts and is supported by the first guide roller 120A; and at least one second plasma unit 130B that sprays plasma onto a second portion of the electrode foil E that contacts and is supported by the second guide roller 120B.

[0065] Figure 3 An electrode surface treatment device 100B according to another modified embodiment of the present disclosure is illustrated.

[0066] like Figure 3 As shown in Figure 1 The electrode surface treatment device 100 shown in FIG. 1 is the same as the electrode surface treatment device 100 shown in FIG. 1 , and the electrode surface treatment device 100B according to another modified embodiment of the present disclosure may include an unwinder 110, a guide roller 120' and a plasma unit 130. The electrode surface treatment device 100B is the same as the electrode surface treatment device 100 shown in FIG. Figure 1 The electrode surface treatment device 100 shown in FIG. 1 is different in the structure of the guide roller 120 ′, the arrangement of the plasma unit 130 , and the plasma spraying method.

[0067] That is to say, if we refer to Figure 1 As described above, the unwinder 110 is configured to unwind the electrode foil E wound into a roll so as to move along the longitudinal direction (machine direction), that is, the length direction of the electrode foil E.

[0068] The guide roller 120 ′ is configured to contact the electrode foil E moving in the longitudinal direction and support the electrode foil E, thereby guiding the movement of the electrode foil E.

[0069] In particular, with Figure 1 Unlike the electrode surface treatment device 100 in FIG. 1 , the guide roller 120 ′ of the electrode surface treatment device 100B is configured to have a hollow portion 122 therein. In addition, the guide roller 120 ′ may have a through hole 124 provided on an outer surface thereof to communicate with the hollow portion 122.

[0070] In this case, the through hole 124 may extend in the transverse direction, i.e., the width direction of the electrode foil E, in the form of a long hole, a slit, or a notch having a predetermined width W. The extension length L of the through hole 124 extending in the transverse direction as described above may be smaller than the width of the electrode foil E to be subjected to the surface treatment.

[0071] The plasma unit 130 is configured to perform surface treatment by continuously spraying plasma onto the surface of the electrode foil E while the electrode foil E moves.

[0072] In particular, with Figure 1 Unlike the electrode surface treatment apparatus 100 in FIG. 1 , the plasma unit 130 of the electrode surface treatment apparatus 100B may be configured to spray plasma onto a portion of the electrode foil E that contacts and is supported by the guide roller 120 , thereby performing surface treatment.

[0073] In addition, the plasma unit 130 may be configured to be disposed in the hollow portion of the guide roller 120' and supported by the guide roller 120'. In this case, the plasma unit 130 may eject plasma onto the surface of the electrode foil E through the through hole 124 of the guide roller 120'. For this purpose, unlike a general roller that rotates around a rotation axis, the guide roller 120' is fixed in a certain posture. The electrode foil E may move by sliding in contact with the outer surface of the guide roller 120' formed with the through hole 124.

[0074] As described above, according to the present disclosure, the tension of the electrode foil E can be maintained while the plasma is sprayed, thereby preventing deformation or damage of the electrode foil due to the spray pressure of the plasma, such as wrinkles, wrinkles, etc., and improving the yield of good products. In addition, the space required for arranging the plasma unit can be reduced, and a support structure for supporting the plasma unit can be excluded.

[0075] In one embodiment, the electrode surface treatment device 100B may include a plurality of plasma units 130. In this case, the plurality of plasma units may be arranged in a transverse direction, that is, a width direction of the electrode foil E, to spray plasma over the entire width of the electrode foil E.

[0076] In addition, in one embodiment, the electrode surface treatment device 100B may include a plurality of guide rollers 120'. In this case, the plurality of guide rollers may include a first guide roller 120'A that contacts the lower surface of the upper surface and the lower surface of the electrode foil E and supports the electrode foil E, and a second guide roller 120'B that contacts the upper surface of the electrode foil E and supports the electrode foil E.

[0077] In this case, the plurality of plasma cells may include at least one first plasma cell 130A disposed in the hollow portion of the first guide roller 120 ′A and at least one second plasma cell 130B disposed in the hollow portion of the second guide roller 120 ′B.

[0078] At least one first plasma unit 130A may spray plasma onto a first portion of the electrode foil E in contact with and supported by the first guide roller 120'A. In addition, at least one second plasma unit 130B may spray plasma onto a second portion of the electrode foil E in contact with and supported by the second guide roller 120'B.

[0079] Figure 4 Illustrated Figure 3 The guide roller 120 ′ of the electrode surface treatment device 100B shown in FIG.

[0080] like Figure 4 As shown in FIG, the guide roller 120 ′ is configured to contact the electrode foil E moving in the longitudinal direction and support the electrode foil E, thereby guiding the movement of the electrode foil E. In particular, the guide roller 120 ′ may have a hollow portion 122 and through holes 124 provided on an outer surface thereof.

[0081] The through hole 124 may extend in the transverse direction (X-axis direction), i.e., the width direction of the electrode foil E, in the form of a long hole, a slit, or a notch having a predetermined width W. In this case, the extension length L of the through hole 124 may be smaller than the width of the electrode foil E to be subjected to the surface treatment.

[0082] Figure 5 Illustrated along Figure 4 2 is a cross-sectional view of the guide roller 120 ′ taken along the line S1 - S1 ′ in FIG.

[0083] like Figure 5 As shown in FIG. 1 , a plurality of plasma units 130 may be disposed in the hollow portion 122 of the guide roller 120 ′. In this case, the plurality of plasma units 130 may be arranged side by side in the transverse direction (X-axis direction). In addition, the plasma jet nozzles of the respective plasma units 130 may be aligned with the through holes 124 of the guide roller 120 ′.

[0084] The plasma unit 130 disposed in the hollow portion 122 of the guide roller 120 ′ as described above may spray plasma onto the surface of the electrode foil E through the through hole 124 formed on the guide roller 120 ′.

[0085] In addition, since the length of the through hole 124 is smaller than the width of the electrode foil E, the upper opening of the through hole 124 is completely covered by the electrode foil E. As a result, the inner space of the through hole 124 is filled with air excited by plasma.

[0086] For example, the through hole 124 may be formed on the outer surface of the guide roller 120' to have a depth of about 4 mm to 8 mm and a length smaller than the width of the electrode foil E, thereby providing a space for connecting the plasma unit 130 and the electrode foil E. The above-mentioned space provided between the plasma unit 130 and the electrode foil E serves as a chamber for containing plasma gas. As a result, plasma treatment can be uniformly performed on the entire surface of the electrode foil E facing the upper opening of the through hole 124.

[0087] In addition, for the surface treatment using plasma, low-temperature plasma is sprayed at high pressure, so that the electrode foil E supported by the outer surface of the guide roller 120' can be pushed upward from the bottom by the spray pressure of the plasma, thereby generating tension on the electrode foil E. Therefore, deformation or damage of the electrode foil such as wrinkles and wrinkles due to the plasma pressure can be prevented, and the yield of good products can be improved.

[0088] As will be described again below, the electrode foil E' whose surface has been plasma-treated as described above may be transferred to a coating device (not shown) that performs a coating process.

[0089] Figure 6 and Figure 7 The effects of surface treatments according to the present disclosure are illustrated.

[0090] like Figure 6 and Figure 7 As shown in , a surface energy measurement test using Dyne Ink was performed to analyze the effect of the surface treatment according to the present disclosure. In this test, aluminum electrode foils of the same thickness were used.

[0091] First, if Figure 6 As shown in , when 30 [dyn] or 32 [dyn] dyne ink is applied to the surface of the aluminum electrode foil before surface treatment, the wettability is relatively good. However, it can be seen that when 34 [dyn] or more dyne ink is applied, the wettability is significantly deteriorated.

[0092] On the other hand, Figure 7 As shown in , when dyne ink is applied on the surface of the aluminum electrode foil processed by the surface treatment using plasma according to the present disclosure, the wettability is good up to 56 [dyn]. That is, it can be seen that the surface energy of the aluminum electrode foil is significantly increased by the surface treatment according to the present disclosure.

[0093] As described above, as the surface energy of the aluminum electrode foil increases, the adhesion between the electrode foil and the electrode mixture can be enhanced, thereby improving the quality of the electrode. In addition, among the electrode active material and the binder included in the electrode mixture, the amount of the binder added to increase the adhesion is reduced, and the amount of the electrode active material will increase in proportion to the reduced amount of the binder, thereby increasing the capacitance and energy density of the electrode. In addition, since there is no need to use expensive primer foil to increase the adhesion of the electrode foil, the manufacturing time of the electrode can be shortened and its manufacturing cost can be reduced.

[0094] Figure 8 is a block diagram illustrating an electrode coating system 2 according to an embodiment of the present disclosure.

[0095] like Figure 8 As shown in , an electrode coating system 2 according to an embodiment of the present disclosure may include an electrode surface treatment device 10 corresponding to any one of the electrode surface treatment devices 100 , 100A, and 100B described above; and a coating device 20 .

[0096] As described above, the electrode surface treatment device 10 may perform surface treatment on the electrode foil E using plasma and transfer the surface-treated electrode foil E′ to the coating device 20 .

[0097] The coating device 20 may be configured to form a coating on the surface of the surface-treated electrode foil E' by applying various coating processes. For example, the coating device 20 may form a coating on the surface of the corresponding electrode foil E' by applying a dry coating process or a wet coating process.

[0098] Fig. 9 An electrode coating system 2A according to one embodiment of the present disclosure is illustrated.

[0099] like Fig. 9 As shown in , an electrode coating system 2A according to an embodiment of the present disclosure may include an electrode surface treatment device 10 corresponding to any one of the electrode surface treatment devices 100 , 100A, and 100B described above; and a coating device 20A.

[0100] As described above, the electrode surface treatment device 10 can perform surface treatment on the electrode foil E using plasma and transfer the surface-treated electrode foil E′ to the coating device 20A.

[0101] The coating device 20A may be configured to form a coating on the surface of the surface-treated electrode foil E' by applying a dry coating process. To this end, the coating device 20A may include: a conveying roller 22 for conveying the electrode foil E', a feeder 24 for supplying a powdered electrode mixture including an electrode active material to the surface of the electrode foil E', a pressing roller 26 for pressing the electrode mixture onto the surface of the electrode foil E', and a rewinder 28 for winding the coated electrode CE into a roll shape.

[0102] In addition, the electrode mixture for manufacturing the dry electrode may include an electrode active material and a polymer binder, and may further include a conductive material, a filler, etc. according to an embodiment.

[0103] The electrode active material may be configured as a positive electrode active material or a negative electrode active material according to the polarity of the dry electrode to be manufactured.

[0104] The positive electrode active material may include: lithium transition metal oxide; lithium metal iron phosphate; lithium-nickel-manganese-cobalt oxide; an oxide in which lithium-nickel-manganese-cobalt oxide is partially replaced by another transition metal; or two or more of the above materials, but not limited thereto. For example, the positive electrode active material may be: a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), etc., or a compound substituted by one or more transition metals; a compound having the chemical formula Li 1+x Mn 2-x Lithium manganese oxides represented by LiMnO4 (wherein x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiV3O4, V2O5, Cu2V2O7, etc.; 1-x M x O2 (wherein M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3) represented by a Ni-based lithium nickel oxide; 2-x M x Lithium manganese composite oxide represented by Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu, or Zn); lithium metal phosphate LiMPO4 (wherein M is Fe, Co, Ni, or Mn); lithium-nickel-manganese-cobalt oxide Li 1+x (Ni a Co b Mn c ) 1-cO2 (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, Li a [Ni b Co c Mn d Al e 1-f M1 f O2 (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; 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 partially substituted with another transition metal, Li 1+x (Ni a Co b Mn c M d ) 1-c O2 (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 compound; or Fe2(MoO4)3, but not limited thereto.

[0105] For example, the negative electrode active material may include: carbon, such as non-graphitized carbon, graphitized carbon, etc.; metal composite oxides, such as Li x Fe2O3 (0 ≤ x ≤ 1), Li x WO2 (0 ≤ x ≤ 1), Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, or Ge; Me’: Al, B, P, Si, elements of Groups 1, 2, and 3 of the periodic table, or halogen, 0 ≤ x ≤ 1, 1 ≤ y ≤ 3, 1 ≤ z ≤ 8), etc.; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; silicon-based oxides, such as SiO, SiO / C, SiO2, etc.; metal oxides, such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; conductive polymers, such as polyacetylene; Li-Co-Ni-based materials; or two or more of the above materials, but not limited thereto.

[0106] ​The polymer binder can include PTFE (polytetrafluoroethylene), polyolefin or their mixture. For example, the binder polymer can include PTFE more than 60wt% based on the total weight. In this case, the binder polymer can further include one or more of the following: PEO (polyethylene oxide), PVdF (polyvinylidene fluoride), PVdF-HFP (polyvinylidene fluoride-hexafluoropropylene copolymer) and polyolefin-based polymer.

[0107] The conductive material may include a material having conductive properties and not causing chemical changes 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, thermal black, etc.; conductive fibers, such as carbon fibers or metal fibers; metal powders, such as carbon fluoride powders, aluminum powders, nickel powders, etc.; conductive whiskers, such as zinc oxide, potassium titanate, etc.; conductive metal oxides, such as titanium oxide, etc.; conductive materials, such as polyphenylene derivatives, etc.; or two or more of the above materials. In order to uniformly mix and improve conductivity, the conductive material may include one or more selected from the group consisting of the following materials: activated carbon, graphite, carbon black, and carbon nanotubes. In addition, since linear conductive materials such as carbon fibers, etc. have difficulty in obtaining high dispersibility in consideration of the manufacturing process of the electrode mixture for the electrode, they may be minimally included or not included in the powder.

[0108] The filler is a component that inhibits electrode expansion and may include a fiber material that does not cause chemical changes in the secondary battery. For example, the filler may include: an olefin polymer such as polyethylene, polypropylene, etc.; or a fiber material such as glass fiber, carbon fiber, etc.; or two or more of the above materials.

[0109] Fig.10 An electrode coating system 2B according to another embodiment of the present disclosure is illustrated.

[0110] like Fig.10 As shown in , an electrode coating system 2B according to another embodiment of the present disclosure may include an electrode surface treatment device 10 corresponding to any one of the electrode surface treatment devices 100 , 100A, 100B described above; and a coating device 20B.

[0111] As described above, the electrode surface treatment device 10 can perform surface treatment on the electrode foil E using plasma and transfer the surface-treated electrode foil E′ to the coating device 20B.

[0112] The coating device 20B may be configured to form a coating layer on the surface of the surface-treated electrode foil E' by applying a dry coating process.

[0113] To this end, the coating device 20B may include: a conveying roller 22B for conveying the electrode foil E', an extruder 24B for producing an electrode film C for coating by compressing or extruding a powdered electrode mixture including an electrode active material, a laminating roller 26B for pressing the electrode film onto the surface of the electrode foil E', and a rewinder 28B for winding the coated electrode CE into a roll shape.

[0114] In addition, although Fig.10 The electrode film is shown to be produced by an extruder 24b, but it can also be produced by compressing a powdered electrode mixture using a plurality of calendar rolls.

[0115] As described above, according to the present disclosure, the surface energy of the electrode foil may be increased by performing surface treatment on the electrode foil using plasma to enhance adhesion between the electrode foil and the electrode mixture, thereby improving electrode quality.

[0116] Furthermore, among the electrode active material and the binder included in the electrode mixture, the amount of the binder added for attachment to the electrode foil is reduced, and the amount of the electrode active material will increase in proportion to the reduced amount of the binder, thereby increasing the capacity and energy density of the electrode.

[0117] In addition, since there is no need to use an expensive primer foil to increase the adhesion of the electrode foil, the manufacturing time and cost of the electrode can be shortened.

[0118] Furthermore, since the surface treatment using plasma is performed during the conveyance of the electrode foil, there is no need to prepare a separate plasma treatment space, and the continuity of the dry manufacturing process can be ensured and the manufacturing time can be further shortened.

[0119] Furthermore, plasma may be sprayed to a portion of the electrode foil that contacts and is supported by the guide roller, thereby preventing deformation or damage of the electrode foil such as wrinkles or wrinkles due to spray pressure of plasma and improving yield of good products.

[0120] Furthermore, since the electrode surface treatment device according to the present disclosure performs surface treatment of the electrode foil before the coating process of the electrode foil, it is independent of the electrode coating method and can be applied to both dry electrode manufacturing processes and wet electrode manufacturing processes, thereby improving electrode quality.

[0121] In addition, the embodiments according to the present disclosure may also solve various other technical problems other than those mentioned in the present application in the relevant technical fields and related technical fields.

[0122] So far, the present disclosure has been described with reference to specific embodiments. However, it will be clearly understood by those skilled in the art that various modified embodiments can be implemented within the technical scope of the present disclosure. Therefore, the embodiments disclosed above should be considered to be intended to describe the present disclosure, rather than to limit the present disclosure. In other words, the true scope of the technical concept of the present disclosure is shown in the claims, and all differences within the scope equivalent thereto should be interpreted as included in the present disclosure.

Claims

1. An electrode surface treatment device, comprising: a guide roller configured to contact the electrode foil moving in a longitudinal direction (machine direction) and support the electrode foil, thereby guiding the movement of the electrode foil; and A plasma unit is configured to perform a surface treatment on the electrode foil by spraying plasma onto the electrode foil while the electrode foil moves.

2. The electrode surface treatment device according to claim 1, The plasma unit is configured to spray plasma onto a portion of the electrode foil that is in contact with and supported by the guide roller.

3. The electrode surface treatment device according to claim 1, A plurality of plasma units are provided therein, and The plurality of plasma units are configured to be arranged along a transverse direction and respectively spray plasma onto the electrode foil.

4. The electrode surface treatment device according to claim 1, A plurality of guide rollers are provided, and The plurality of guide rollers include: a first guide roller that contacts a lower surface of an upper surface and a lower surface of the electrode foil and supports the electrode foil; as well as A second guide roller contacts an upper surface of the electrode foil and supports the electrode foil.

5. The electrode surface treatment device according to claim 4, A plurality of plasma units are provided therein, and Wherein the plurality of plasma units comprises: at least one first plasma unit configured to spray plasma onto a first portion of the electrode foil in contact with and supported by the first guide roller; as well as At least one second plasma unit is configured to spray plasma onto a second portion of the electrode foil that is in contact with and supported by the second guide roller.

6. The electrode surface treatment device according to claim 1, wherein the guide roller has a hollow portion therein, and The plasma unit is disposed in the hollow portion of the guide roller.

7. The electrode surface treatment device according to claim 6, wherein the guide roller has a through hole provided on an outer surface of the guide roller to communicate with the hollow portion, and The plasma unit is configured to spray plasma onto the surface of the electrode foil through the through hole.

8. The electrode surface treatment device according to claim 7, The through hole is configured in the form of a long hole or a slit extending in a transverse direction and having a predetermined width.

9. The electrode surface treatment device according to claim 8, The extension length of the through hole extending along the transverse direction is smaller than the width of the electrode foil.

10. The electrode surface treatment device according to claim 6, A plurality of guide rollers and a plurality of plasma units are respectively arranged therein, wherein at least one first plasma unit among the plurality of plasma units is disposed in a hollow portion of a first guide roller among the plurality of guide rollers, and At least one second plasma unit among the plurality of plasma units is disposed in a hollow portion of a second guide roller among the plurality of guide rollers.

11. The electrode surface treatment device according to claim 1, further comprising an unwinder configured to unwind the electrode foil wound into a roll to move along the first direction, wherein the guide roller is configured to guide the electrode foil moved by the unwinder.

12. The electrode surface treatment device according to claim 1, The electrode foil is made of a material including aluminum.

13. An electrode coating system comprising: The electrode surface treatment device according to any one of claims 1 to 12; and A coating device is configured to form a coating layer on the surface of the electrode foil surface-treated by the electrode surface treatment device.

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