WO2018008806A1

WO2018008806A1 - Separation film processing method for secondary battery using atmospheric pressure dielectric barrier discharge plasma

Info

Publication number: WO2018008806A1
Application number: PCT/KR2016/012438
Authority: WO
Inventors: 임유봉; 최원호
Original assignee: 주식회사 플라즈맵
Priority date: 2016-07-06
Filing date: 2016-11-01
Publication date: 2018-01-11
Also published as: KR20180005472A; KR101882329B1

Abstract

The present invention provides a secondary battery and a manufacturing method therefor. A secondary battery comprises a negative electrode, a positive electrode, a separation film and an electrolyte. A surface or both surfaces of the separation film includes: a hydrophilic processing region that is hydrophilically-processed with plasma by means of atmospheric pressure dielectric barrier discharge, and that has a pattern of a plurality of periodic lines; and a hydrophobic processing region.

Description

Separation method of secondary battery using atmospheric dielectric barrier discharge plasma

The present invention relates to a method for manufacturing a lithium secondary battery, and more particularly, to a dielectric barrier discharge (DBD) device at atmospheric pressure, a mask disposed on the dielectric barrier discharge device, and an optional pressure control module. The present invention relates to a method for manufacturing a lithium secondary battery for selectively surface treating a separator film of a secondary battery. Accordingly, electrolyte pourability and process productivity may be improved.

As demand for mobile devices and electric vehicles continues to increase, the demand for secondary batteries as energy storage devices is rapidly increasing. Along with such increasing demand, research on the development of material technology and manufacturing process technology for improving energy density and cycle performance of secondary batteries has been continuously conducted.

In the secondary battery manufacturing process, the lamination process of the separator film and the electrode film is one of the most important processes for determining the performance of the secondary battery. Research has been conducted to secure electrical conductivity while increasing adhesion strength at the interface. Recently, along with the development of a separator film for improving adhesion, a surface treatment process of a separator film using an atmospheric plasma has been developed. As the energy density of the secondary battery increases and the separator film becomes thin for this purpose, there is a problem in that the damage of the separator film by the conventional plasma treatment and the defective rate of the manufacturing process become high. In addition, in the process of injecting the electrolyte solution with increasing energy density, the efficiency of penetration of the electrolyte solution is greatly reduced, resulting in a decrease in the productivity of the secondary battery manufacturing process and the generation of a defective rate due to incomplete filling of the electrolyte. .

Korean Patent No. 10-0760551 discloses a large-area plasma generating apparatus that is uniform and stable under normal pressure for surface treatment. A second electrode disposed to form a discharge space by a predetermined distance from the first electrode applied through the matching circuit in a longitudinal direction, and a dielectric barrier layer covering both the first electrode for stable plasma discharge. It is characterized by including. However, in Patent No. 10-0760551, arc and filamentary discharges to a treatment object are generated by local electric field formation by accumulated charges accumulated on the dielectric surface surrounding the first electrode, and as a result, a separator film Has a problem that leads to electrical damage and poor secondary battery provided correction accordingly. In addition, the development of various process technologies for improving the injectionability of the electrolyte by the absence of the plasma source technology that can selectively process the separator film using a conventional atmospheric plasma has been tried.

Secondary batteries are classified according to the structure of the electrode assembly having a positive electrode / membrane / cathode structure. Typically, a long sheet-shaped positive electrode and negative electrode are wound with a separator interposed therein. (Winding type) electrode assembly, a stacked type electrode assembly in which a plurality of positive and negative electrodes cut into units of a predetermined size are sequentially stacked with a separator, and positive and negative electrodes of a predetermined unit are interposed with a separator And a stack / foldable electrode assembly having a structure in which bi-cell or full cells are stacked.

Lithium secondary batteries of various structures are manufactured by sealing other portions except the electrolyte inlet after interposing an electrode assembly therein and injecting an electrolyte through the electrolyte inlet. After injecting the electrolyte, press the pouch to remove the air bubbles in the electrode assembly and the inside of the pouch, or let the air flow out naturally to remove the air bubbles inside the battery. To completely seal the secondary battery. However, as the active material is loaded at a high density onto the current collector to manufacture the secondary battery at a high energy density, the electrolyte injection property injected into the electrode assembly is lowered, resulting in a long pouring time and a poor pouring process.

Korean Patent Laid-Open Publication No. 10-2016-0016040 provides a step in the negative electrode active material of a lithium-ion polymer battery to improve the liquid-liquidity of the electrolyte and to improve productivity of the manufacturing process and to improve the repeatability of the secondary battery. A lithium secondary battery and a method of manufacturing the same are disclosed. In the lithium secondary battery, other parts except the electrolyte injection hole are sealed after the electrode assembly is interposed, and the electrolyte is injected through the electrolyte injection hole. After the electrolyte injection process, in order to remove the air bubbles (pore) present in the electrode assembly and the inside of the pouch (pores) or to remove the air bubbles in the battery by naturally allowing the air bubbles to go out. After that, the electrolyte injection hole is completely sealed to manufacture a secondary battery. However, as the active material is loaded onto the current collector in a high density to manufacture a secondary battery having a high energy density, the electrolyte injection property injected into the electrode assembly is lowered, and the pouring time and the aging process time are long, There is a problem that the defective rate is high. Korean Patent Laid-Open Publication No. 10-2016-0016040 has shown that by forming a step in the negative electrode active material layer to form a flow path of the electrolyte, and thus the liquid-liquidity is improved. However, in order to change the structure of forming a step in the negative electrode active material layer, an additional coating and forming process of the negative electrode current collector is required. To this end, not only the change of the secondary battery manufacturing line is required but also has a problem of lowering the productivity and cost competitiveness of the manufacturing process.

Although research has been made to solve these problems, there has not been proposed a high-volume production process technology capable of improving electrolyte pourability while securing plasma stability in the manufacturing process of a high energy density secondary battery. Therefore, it is necessary to develop a plasma surface treatment apparatus and a process technology capable of performing stable plasma surface treatment and spatially selective plasma surface treatment, thereby improving electrolyte injection performance and improving productivity and cost competitiveness of the manufacturing process. Can have

Accordingly, the present inventors have intensively studied to develop a manufacturing process technology for improving electrolyte injection property in a secondary battery manufacturing process, and have completed the present invention as a selective plasma surface treatment apparatus and process technology for a secondary battery separator film.

The problem to be solved by the present invention is to provide a selective surface treatment process of the secondary battery separator film. Thereby, the injection property of electrolyte solution and productivity of a manufacturing process improve.

Another object of the present invention is to provide a high performance secondary battery technology with improved repeatability of secondary batteries through selective plasma surface treatment.

If the problem to be solved by the present invention is not limited to the above-mentioned problems, other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

A secondary battery according to an embodiment of the present invention includes a negative electrode, a positive electrode, a separator, and an electrolyte. One or both surfaces of the separator includes a hydrophilic treatment region and a non-hydrophilic treatment region of a plurality of periodic line pattern types hydrophilically treated with plasma by an atmospheric pressure dielectric barrier discharge.

In one embodiment of the present invention, the width of the non-hydrophilic treatment region is 5 millimeters to 20 millimeters, the width of the hydrophilic treatment region is 5 millimeters to 20 millimeters, and both sides of the separation membrane is disposed in the hydrophilic treatment region do.

In the method of manufacturing a secondary battery according to an embodiment of the present invention, a hydrophilic treatment region and a non-hydrophilic treatment region in the form of a plurality of periodic line patterns selectively hydrophilized by selectively exposing the dielectric membrane discharge to one surface of the separator may be selectively exposed. Performing a selective surface treatment; Laminating the hydrophilized membrane and an electrode to provide an electrode assembly; And sealing the electrode assembly with a sealing member and injecting an electrolyte through the electrolyte injection hole of the sealing member.

In one embodiment of the present invention, the selective surface treatment is performed using a plasma formed only in the openings using a conductive mask mounted on a dielectric barrier discharge linear source and having a plurality of openings spaced apart from each other. The supporting membrane supporting portion may be a conductive material, and the supporting membrane may be maintained at an equipotential with the conductive mask.

In an exemplary embodiment, the method may further include selectively injecting an inert gas into the closed region of the conductive mask to prevent the plasma formed in the opening from diffusing into the closed region of the conductive mask.

In one embodiment of the present invention, the conductive separator support may be a roller in contact with the separator.

In one embodiment of the present invention, the roller and the conductive mask may be grounded.

As described above, according to the solution of the present invention, it is possible to selectively control the adhesion between the electrode film through the selective plasma treatment to the separator film of the secondary battery. By using this, the injection time of the electrolyte is shortened and the defective rate of the pouring process is reduced.

In addition, the installation of the plasma source for the selective surface treatment can be made through a simple module replacement and mounting in the existing mass production process it is easy to apply the technology and ensure economic feasibility.

1 shows a dielectric barrier discharge plasma processing system of a separator according to an embodiment of the present invention.

2 is a conceptual diagram illustrating a plasma treatment and an electrode lamination process of a separator according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line II ′ of FIG. 2.

4 is a cross-sectional view taken along the line II-II ′ of FIG. 2.

5 is a cross-sectional view illustrating the electrode assembly after the lamination step.

6 is a cross-sectional view illustrating the stacked electrode assemblies after the lamination process.

It is a conceptual diagram explaining sealing and injection of electrolyte solution by a pouch.

8 is an experimental result of measuring the contact angle by hydrophilic treatment according to the position.

9A is a perspective view illustrating a dielectric barrier discharge device according to another embodiment of the present invention.

FIG. 9B is a cross-sectional view taken along the line C-C of FIG. 9A.

FIG. 9C is a cross-sectional view taken along the line D-D of FIG. 9A.

FIG. 9D is a cross-sectional view taken along the line E-E of FIG. 9A.

FIG. 9E is a perspective view illustrating the dielectric barrier portion and the insulating block of the dielectric barrier discharge device of FIG. 9A.

9F is a perspective view illustrating a power electrode of the dielectric barrier discharge device of FIG. 9A.

9G is a perspective view illustrating an insulating block of the dielectric barrier discharge device of FIG. 9A.

FIG. 9H is a perspective view illustrating the ground electrode of the dielectric barrier discharge device of FIG. 9A. FIG.

FIG. 9I is a plan view illustrating a bottom plate of the dielectric barrier discharge device of FIG. 9A.

20: secondary battery

22: separator

22a: hydrophilic treatment area

22b: non-hydrophilic treatment area

24: cathode

26: anode

An optional surface treatment process using an atmospheric dielectric barrier discharge plasma is provided. Specifically, a treatment method of a selective surface treatment process for a separator film of a secondary battery using a plasma source is proposed. The plasma source has a dielectric barrier discharge (DBD) structure at atmospheric-pressure, and uses a mask and a local pressure control module to locally form a plasma.

The selective surface treatment process may selectively control the adhesion (hydrophilicity) between the separator and the battery electrode, whereby the electrolyte may improve the injection efficiency and the production efficiency of the secondary battery manufacturing process.

The present invention installs a mask that provides spatial selectivity to a plasma source. The mask has a region (mask region) covering the plasma powered electrode and an open region not covered by the mask. The mask area is set to have the same potential as the support for supporting the treatment object. In the mask region, there is no potential difference between the mask and the treatment object (separation film of the secondary battery), thereby effectively preventing plasma generation in this region and providing a plasma treatment with spatial selectivity.

The open region corresponds to a plasma treatment region in which the treatment object is plasma treated (hydrophilic treatment). The plasma treatment region of the treatment object selectively hydrophilizes the treatment object by active species formed by plasma. Hydrophilic treatment of the separator can improve the adhesion with the battery electrode. However, when hydrophilic treatment of one or both surfaces of the separation membrane, the electrolyte injection performance may be significantly reduced. Therefore, the selective dielectric barrier discharge plasma treatment according to the embodiment of the present invention can simultaneously improve the electrolyte injection performance while increasing the overall adhesion. The hydrophilic treatment region of the separator may be 50 to 80 percent of the total region. As the hydrophilic treatment region is increased, the adhesion may be increased, but the liquid injection property may be decreased.

On the other hand, the plasma treatment region has a relatively higher pressure than the untreated region due to the injection gas or the reaction gases. In the absence of injection gas, discharge stability decreases due to arc generation or the like. The active species generated by plasma generation may diffuse into the untreated region and indirectly affect the selective treatment performance. As a result, the boundary between the hydrophilic treatment region and the non-hydrophilic treatment region is unclear, and the degree of hydrophilic treatment can gradually decrease spatially. Accordingly, process stability of the electrolyte injection process can be reduced. Therefore, the width of the non-processed region of the treatment object and the boundary region of the treatment region needs to be reduced. To solve this problem, if a separate inert gas is selectively injected into the untreated region onto the surface of the treated object, interference by the active species that penetrates into the untreated region can be prevented, and the selective plasma treatment performance can be greatly improved. That is, by setting the pressure in the non-processing region to be higher than the pressure in the processing region and setting the inert gas to flow from the non-processing region to the processing region, the boundary region between the processing region and the non-processing region can be narrowed. Such selective plasma surface treatment may be performed by a linear dielectric barrier discharge source.

In order to apply such a selective plasma treatment process to a secondary battery manufacturing process, a selective surface treatment process is possible by replacing only a plasma surface treatment apparatus that processes a whole existing area. In addition, by the selective surface treatment, the electrolyte injection performance can be remarkably improved as compared with the plasma surface treatment of the entire area. Accordingly, the productivity of the manufacturing process can be greatly improved.

Conventional dielectric barrier discharges can damage the separator film by the plasma source and cause product defects. Accumulated charge that accumulates on the surface of the plasma source dielectric barrier layer creates a locally high electric field, resulting in a high current density arc. Capacitive charge is surface accumulated charge in a dielectric barrier discharge (DBD) where current flow is blocked by the dielectric layer and accumulated on the dielectric surface. Thus, arc discharge can operate as a cause of film damage. This arc discharge is the main cause for the continuous failure rate, and the solution is to suppress the formation of memory charge.

The dielectric barrier layer forms a locally high electric field by micro damage to the ceramic surface and can generate arcs of high current density along the electric field. If there is surface damage to the dielectric barrier material, the failure rate increases.

Conventional direct processing dielectric barrier discharge has a problem that the stability is lowered due to the generation of arc by memory charge or surface charge. In addition, in the case of an indirect dielectric barrier discharge using secondary discharge, it is difficult to ensure uniformity of injected velocity of the flow and thus it is difficult to secure spatial uniformity of surface treatment. Indirect methods using Afterglow have lower productivity than direct processes.

Dielectric barrier discharge plasma generating apparatus according to an embodiment of the present invention 1) to ensure stability through the surface charge trapping, has a high productivity by the direct DBD method, and improves the productivity and uniformity through Afterglow.

In the plasma generating apparatus according to an embodiment of the present invention, as the distance between the high voltage applying electrode and the susceptor is increased, the plasma is discharged on the surface of the dielectric barrier layer, and afterglow is caused by rapid fluid flow. The hydrophilic treatment of the exposed surface of the workpiece disposed on the susceptor can be performed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in different forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art, and the invention is defined only by the scope of the claims.

Like reference numerals refer to like elements throughout the specification. Accordingly, the same or similar reference numerals may be described with reference to other drawings, even if not mentioned or described in the corresponding drawings. Also, although reference numerals are not indicated, they may be described with reference to other drawings.

Referring to FIG. 1, the dielectric barrier discharge plasma processing system 10 performs a hydrophilic treatment of a separator film 22 wound in a roll shape, a roller 90 for conveying the separator film, and the separator film. The plasma device 100 may be included. The hydrophilic separator film may be provided in a lamination process. There may be a plurality of plasma apparatuses 100. One plasma apparatus may hydrophilize one surface of the separator film to have a line pattern, and the other plasma apparatus may hydrophilize the other surface of the separator film to have a line pattern. The hydrophilic treatment of one side and the other side may be performed sequentially.

Typically, the separator 22 used in the battery among the electrochemical devices should be electrically isolated from each other between the electrodes, and maintain a predetermined ion conductivity between the electrodes. Accordingly, the separator used in the battery is made of a thin porous insulating material having high ion permeability, good mechanical strength, and good long-term stability against chemicals and solvents used in the electrolyte of the system, for example, a battery. In such batteries, the separator must be permanently elastic and must follow movement in the system, eg, electrode pack, during charging and discharging. The separator for Ni-MH secondary batteries, which is an environmentally friendly battery using a soluble electrolyte, should have alkali resistance by using an alkaline water soluble electrolyte, and should be economical without being reactive between electrodes. When the polyolefin-based polymer material is used as the separator for the Ni-MH secondary battery, a hydrophilic property does not have an affinity for a water-soluble alkaline electrolyte, so that a separate hydrophilization treatment process is essential for applying to the Ni-MH secondary battery. It must be accompanied. As the hydrophilization treatment, a dielectric barrier plasma treatment may be used.

Meanwhile, when all surfaces of the separator film are hydrophilic, adhesion may be improved, but the electrolyte injection speed is decreased and the possibility of defects is increased. Thus, the separator film is optionally hydrophilized. On the other hand, both side portions of the separator 22 may be hydrophilic treatment to prevent lifting.

According to one embodiment of the invention, a plasma hydrophilic treatment with spatial selectivity is proposed. Local plasma treatment needs to drastically change the degree of hydrophilic treatment depending on the position. The width of the boundary region between the hydrophilic treatment region and the non-hydrophilic transition region may be 1 millimeter or less. The width of the hydrophilic line pattern and the spacing between the adjacent hydrophilic line patterns (width of the region to be treated) may affect the electrolyte injection rate and defects.

According to one embodiment of the invention, the width of the hydrophilic treatment region may be 5 millimeters to 40 millimeters, and the width of the non-hydrophilic treatment region may be 5 millimeters to 40 millimeters. Preferably, the width of the non-hydrophilic treatment region may be between 5 millimeters and 20 millimeters.

FIG. 3 is a cross-sectional view taken along line II ′ of FIG. 2.

4 is a cross-sectional view taken along the line II-II ′ of FIG. 2.

2 to 8, the secondary battery 20 includes a negative electrode 24, a positive electrode 26, a separator 22, and an electrolyte (not shown). The electrode assembly 21 is composed of an anode / separator / cathode. On one or both surfaces of the separator 22, hydrophilic treatment regions 22a and non-hydrophilic treatment regions 22b of a plurality of periodic line pattern frames hydrophilically treated with plasma by an atmospheric pressure dielectric barrier discharge are provided.

The separator 22 may be coated with a polymer mixture. The dielectric barrier discharge may selectively hydrophilize one side or both sides of the separator 22 in a line form.

The material of the separator substrate may be a polyolefin-based polymer. The dielectric barrier discharge device 100 may include a discharge gas that forms active species in the hydrophilic treatment region 22a and an inert gas that suppresses penetration of the active species in the non-hydrophilic treatment region 22b.

The polymer mixture may include a porous inorganic filler and a binder polymer. The separator 22 may be connected between the inorganic fillers due to the binder polymer on the separator substrate, and may form a heat resistant pore structure due to the empty space between the inorganic fillers.

The positive electrode 26 may be manufactured by applying a slurry made by mixing a positive electrode mixture with a solvent such as NMP onto a positive electrode current collector, followed by drying and rolling. The positive electrode current collector is made from several micrometers to several hundred micrometers in thickness. The anode may be a conductive material.

The negative electrode 24 may be manufactured by coating a negative electrode mixture including a negative electrode active material on a negative electrode current collector and then drying the negative electrode mixture. The negative electrode current collector is made in the thickness of several micrometers to several hundred micrometers. The cathode may be a conductive material.

The electrolyte may include an electrolyte material and a lithium salt. The electrolyte material may be a non-aqueous organic solvent, an organic solid electrolyte, an inorganic solid electrolyte, or the like. The lithium salt may be dissolved in the electrolyte material. The electrolyte may be soaked in the separator 22.

One or both surfaces of the separator 22 may include a hydrophilic treatment region 22a and a non-hydrophilic treatment region 22b in the form of a plurality of periodic line patterns hydrophilically treated with plasma by an atmospheric pressure dielectric barrier discharge using air. . The width W2 of the non-hydrophilic treatment region may be between 5 millimeters and 40 millimeters. The width W1 of the hydrophilic treatment region may be between 5 millimeters and 40 millimeters. The hydrophilic treatment regions are disposed on both sides of the separator.

The manufacturing method of a secondary battery is demonstrated.

Selective surface treatment is performed to have a hydrophilic treatment region 22a and a non-hydrophilic treatment region 22b in the form of a plurality of periodic line patterns selectively selectively exposed to one surface of the separator 22 by atmospheric pressure dielectric barrier discharge. do. The selective surface treatment utilizes a conductive mask 150 provided in a dielectric barrier discharge device for providing hydrophilic and non-hydrophilic treatment regions. In the hydrophilic treatment region, a reactive gas (injection gas) is selectively injected and a plasma is generated. Inert gas is injected into the non-hydrophilic treatment region. The selective surface treatment may be performed using a plasma formed only in the openings 151 using a conductive mask 150 having a plurality of openings 151 mounted on the dielectric barrier discharge linear source and spaced apart from each other. The separator support part 90 supporting the separator may be a conductive material, and the separator support part 90 may be maintained at an equipotential with the conductive mask. The conductive separator support 90 may be a roller in contact with the separator. The roller and the conductive mask may be grounded.

In order to prevent the plasma formed in the opening 151 from diffusing into the closed region of the conductive mask, an inert gas may be selectively injected into the closed region of the conductive mask.

Subsequently, selective surface treatment is performed to have a hydrophilic treatment region and a non-hydrophilic treatment region in the form of a plurality of periodic line patterns selectively hydrolyzed by selectively exposing the other surface of the separator with an atmospheric pressure dielectric barrier discharge.

Subsequently, the hydrophilized membrane and the electrode are laminated to provide an electrode assembly 21.

Subsequently, the electrode assembly 21 is sealed with a sealing member (or a pouch 28) and the electrolyte is injected through the electrolyte injection hole 28 of the sealing member 28. After the electrolyte completely penetrates the separator, the electrolyte injection hole 28 is sealed.

Referring to Figure 8, the contact angle of the electrolyte was measured according to the position. The contact angle is about 110 degrees in the hydrophilic treatment region and the contact angle is about 90 degrees in the non hydrophilic treatment region. The boundary region between the hydrophilic treatment region and the non-hydrophilic treatment region is 1 mm or less. When the separator includes a line-type hydrophilic treatment region and a non-hydrophilic treatment region, the electrolyte injection time is reduced to 1/3 or less as compared with the case where the entire region is hydrophilized. In addition, the defective rate is also significantly reduced.

FIG. 9B is a cross-sectional view taken along the line C-C of FIG. 9A.

FIG. 9C is a cross-sectional view taken along the line D-D of FIG. 9A.

FIG. 9D is a cross-sectional view taken along the line E-E of FIG. 9A.

9A to 9I, the dielectric barrier discharge device 100 according to an embodiment of the present invention may include a ground electrode 110, a power electrode 120, a dielectric barrier 130, and a main gas distribution unit 181. ), An auxiliary gas distributor 182, and a mask unit 150. The power electrode 120 extends in a first direction, a part of which is exposed to the outside, and an AC voltage is applied. The ground electrode 110 extends in the first direction and is disposed to surround the power electrode except for an exposed portion of the power electrode 120. The dielectric barrier portion 130 extends in the first direction and is disposed between the ground electrode 110 and the power electrode 130 and covers the exposed portion of the power electrode 120. Is placed in contact with The mask unit 150 includes at least one main opening 151 and at least one auxiliary opening 153 spaced apart in the first direction, extends in the first direction, and includes the workpiece 164. The exposed portion of the power electrode is disposed in a first region facing each other to generate a plasma through the main opening 151 to selectively process the object to be processed according to the position in the first direction. The main gas distribution unit 181 is embedded in the ground electrode 110 and uniformly supplies a first gas to the exposed portion of the power electrode along the first direction. The auxiliary gas distributor 182 is embedded in the ground electrode 110 and provides a second gas through the auxiliary opening 153 to control the pressure in the first direction.

The power electrode 120 may be formed of a conductor and have a triangular pillar shape. The ground electrode 110 is disposed opposite to both side surfaces (compressed surfaces) of the upper edge of the power electrode 120. The ground electrode 110 is disposed to expose the upper edge of the power electrode. The upper edge of the power electrode 120 and the susceptor 162 perform main dielectric barrier discharge in a first region (main discharge region) via the dielectric barrier portion 130. The subsurface of the power electrode 120 and the ground electrode 110 may perform an auxiliary dielectric barrier discharge in a second region via the dielectric barrier unit 130. When only the main dielectric barrier discharge is formed, a memory charge may be locally formed at the upper edge to cause an arc discharge. In order to reduce the arc discharge, plasma, electrons, and active gases generated in the auxiliary dielectric discharge are supplied to the first region where the main dielectric barrier discharge occurs, so that stable discharge can be performed even at a low voltage. As a result, the discharge stability is improved. For the main dielectric barrier discharge, the vertical distance between the inclined surface of the power electrode 120 and the ground (susceptor) may be on the order of several millimeters. In detail, the vertical distance g1 between the dielectric barrier 130 on the upper edge of the power electrode 120 and the susceptor may be about 1 millimeter. Accordingly, the thickness of the mask part 150 may be less than 1 millimeter. Meanwhile, the vertical distance g2 between the dielectric barrier 130 and the ground electrode 110 on the inclined surface of the power electrode 120 may be about 1 millimeter. The auxiliary dielectric discharge forms a stable plasma to remove memory charges and provide seed charges necessary for the main dielectric discharge. The gas may provide a uniform fluid flow along the side surface (the inclined surface) of the dielectric barrier unit 130 to improve the discharge stability and cool the dielectric barrier unit 130.

The power electrode 120 may include an elongated hole formed therein in the first direction. The refrigerant may flow through the hole. The coolant may be injected from one end of the power electrode and flow in the first direction along the power electrode, and then discharged from the tartan of the power electrode. AC power may be supplied to a central portion of the power electrode 120.

The dielectric barrier unit 130 has a V-shaped beam shape having a predetermined thickness, and the dielectric barrier unit 130 covers the upper edge and the inclined surface of the power electrode 120 and partially covers the inclined surface of the insulating block. Can be. The dielectric barrier 130 may have a constant thickness of several hundred micrometers to several millimeters. The material of the dielectric barrier part may be ceramic or plastic based. According to a modified embodiment of the present invention, the dielectric barrier portion 130 and the insulating block 140 may be integral.

The insulating block 140 may have a triangular pillar shape in a first direction, and an upper edge of the triangular pillar may include a recessed portion 147 to insert the power electrode. The depression 147 may extend in the first direction. The insulating block 140 may be made of ceramic or plastic. The dielectric barrier unit 130 may extend in a first direction to cover the inclined surface of the power electrode and the inclined surface of the insulating block, and may extend in the inclined surface direction to cover a portion of the inclined surface of the insulating block 140.

The insulating block 140 may include a protrusion 142 extending in the first direction and protruding to the inclined surface of the insulating block. The dielectric barrier portion 130 may be disposed to be caught by the protrusion 142. A strong electric field is formed at the lower edge of the power electrode 120, and the power electrode 120 and the ground electrode 110 may cause parasitic discharge or arc discharge in a minute gap. In order to suppress the parasitic discharge, the protrusion 142 of the insulating block is disposed. Accordingly, the path connecting the lower edge of the power electrode 120 and the ground electrode 110 may be bent by the height of the protrusion 142 to suppress parasitic discharge.

The ground electrode 110 may be in the form of a truncated triangular prism that is entirely hollow. Alternatively, an opening having a slit shape extending in the first direction may be disposed at the truncated portion of the ground electrode. The power electrode 120 may be buried in the ground electrode 110, and an upper edge of the power electrode 120 may be disposed below the opening of the ground electrode 110. Alternatively, the ground electrode 120 may be disposed to surround an exposed portion (or an upper edge) extending in the first direction of the power electrode.

An upper edge of the power electrode 120 or an upper edge of the dielectric barrier portion 130 may substantially correspond to the truncated surface of the ground electrode 110.

The ground electrode 110 may include a pair of side ground electrodes 111, a pair of auxiliary side ground electrodes 111a, and a lower ground electrode 116. The side ground electrode 111 is disposed opposite to the inclined surface of the power electrode 120 and the inclined surface of the insulating block 140. The side ground electrode 111 extends in a first direction, and the auxiliary side ground electrode extends perpendicular to the first direction and is disposed at both ends of the insulating block 140.

The main gas distribution part 181 may be formed inside the side ground electrode 111, and supply gas to the inclined surface of the dielectric barrier part 130 at both sides of the power electrode. The main gas distribution part 181 includes a gas flow passage, and is formed between the side ground electrode 111 and the dielectric barrier part 130, and the dielectric barrier part is formed on both sides of the dielectric barrier part 130. Gas can be supplied along the inclined plane. An area where the ground electrode 110 and the power electrode 120 face each other in the gas movement passage may provide an auxiliary discharge space (second area). The auxiliary discharge space may generate an auxiliary dielectric barrier plasma. The gas flow passage may have a slit in the form of a multi-sided surface and may extend along the inclined surface of the dielectric barrier portion. The main gas distributor 181 may provide a gas having a uniform density in the first direction to the mask unit.

The main gas distribution part 181 may further include a ground electrode fluid passage which is serpentine inside the ground electrode and has a slit cross section thereof. In detail, the ground electrode fluid passage may include a first line pattern 112a and a second line pattern 114a extending in a first direction. The side ground electrode 111 may include an upper plate 112 and a lower plate 114, and one surface of the upper plate 112 may include a plurality of first line patterns 112a extending and protruding in a first direction. In addition, one surface of the lower plate may include a plurality of second line patterns 114a extending and protruding in the first direction. The first line pattern 112a and the second line pattern 114a may be alternately disposed. The gas may pass through a serpentine fluid path formed by the first line pattern and the second line pattern through the slit-shaped gas inlet 116 formed on the lower surface of the side ground electrode. Accordingly, the gas may be uniformly spread in the first direction by receiving the resistive force in the diagonal direction. Accordingly, the gas outlet 117 of the side ground electrode may discharge gas in the direction of the dielectric barrier and maintain a uniform density in the first direction.

The side ground electrode 111 may include a ground electrode recess 112b formed to face the lower side edge of the power electrode 120 and extend in the first direction. The ground electrode recess 112b may provide a gas buffer space when the ground electrode recess 112b is not filled with a dielectric.

The ground electrode recess 112b may be filled by the arc prevention insulating block 172. The arc protection insulating block 172 may be a square pillar of ceramic or plastic material extending in the first direction.

An interval between the side ground electrode 111 and the dielectric barrier unit 130 may be 1 mm or less, and the gas flow passage may perform an auxiliary dielectric barrier discharge to provide a plasma to the first region.

The gas discharged from the gas outlet 117 of the main gas distribution part may pass through a space between the arc protection insulating block 172 and the dielectric barrier part 130 to be provided in an auxiliary discharge space (second area). . The arc prevention insulating block 172 may sufficiently reduce the distance between the power electrode and the ground electrode to suppress the dielectric barrier discharge and the arc discharge.

The side ground electrode 111 may include an auxiliary discharge ground electrode part 114b that provides an auxiliary discharge space between the ground electrode 110 and the dielectric barrier part 130. The auxiliary discharge ground electrode part 114b may provide the auxiliary discharge space (second area). The auxiliary discharge ground electrode part 114b may be a metal alloy resistant to thermal deformation. The vertical distance g2 between the auxiliary discharge ground electrode part 114b and the dielectric barrier part 130 may be several millimeters.

If the vertical distance g2 is too large, no auxiliary dielectric barrier discharge occurs. Therefore, only a main dielectric barrier may be generated between the susceptor 162 and the upper edge of the power electrode 120 in the first region, thereby deteriorating discharge stability due to arc discharge.

The side ground electrode 111 may include

auxiliary gas distributors

182 and 183 to receive gas from the ground

electrode fluid passages

112a and 114a having a serpentine structure. The

auxiliary gas distributors

182 and 183 may include an auxiliary ground electrode recess 183 and the auxiliary gas injector 182. The

auxiliary gas distributors

182 and 183 may selectively supply gas to the auxiliary openings of the mask unit. Specifically, the ground electrode recess 112b formed in the side ground electrode may be recessed deeper at a position corresponding to the auxiliary opening to form the auxiliary ground electrode recess 183. The auxiliary ground electrode depression 183 may be formed at each position where the auxiliary opening is disposed along the first direction. The auxiliary ground electrode depression 183 may be connected to the gas outlet 117 to receive gas. The auxiliary gas distribution unit () may provide a gas communication path of a bypass type surrounding the arc prevention insulating block 172. The auxiliary gas injection unit 182 may be a through hole to inject gas into the auxiliary opening 152 of the mask unit.

The lower ground electrode 116 is coupled to the lower surface of the side ground electrode 111 and supports the lower surface of the insulating block 140. The lower ground electrode 116 is formed on an upper surface thereof and is disposed adjacent to a side extending in the first direction and spaced apart from the first trench 215 and the first trench in the opposite direction. It may include an extended second trench 225 disposed adjacent to the side. The first gas outlet 214 is connected through a fluid passage formed inside the bottom ground electrode through a gas inlet 216 disposed around the bottom surface of the first trench 215. The second gas outlet 223 is connected through a fluid passage formed inside the bottom ground electrode through a gas inlet 222 disposed around the bottom surface of the second trench 225.

The first trench 215 has a plurality of first gas outlets 214, the second trench 225 has a plurality of second gas outlets 223, and The second gas outlets may be alternately arranged in the first direction. The first trench 215 is connected to the gas inlet 116 of the one side ground electrode. The second trench 225 is connected to the gas inlet 116 of the other side ground electrode.

The lower ground electrode 116 may include a refrigerant pipe through hole 211 through which a pipe through which refrigerant flows, and a power line through hole 212 through which a power line for supplying AC power may travel.

The mask unit 150 may be disposed on the truncated surface of the ground electrode 110 to selectively process the object 164. The mask unit 150 may include a plurality of main openings 151 and a plurality of auxiliary openings 153 arranged in the first direction. The main opening may have a size of several hundred micrometers to several centimeters. The mask unit 150 has a plate shape having a thickness of 1 millimeter or less, and includes a plurality of main openings 151 arranged along the first direction. The mask unit 150 may be a ceramic, a metal, or a metal alloy.

The auxiliary opening 153 of the mask part may be symmetrically spaced apart from the center line of the mask part. The auxiliary opening 153 may be disposed not to face the power electrode 120 so as not to cause a dielectric barrier discharge. That is, the auxiliary opening may be disposed to face the upper surface of the ground electrode, and may be aligned with the gas outlets of the auxiliary

gas distribution units

182 and 183. The gas discharged by the pair of auxiliary openings may be concentrated at one point of the workpiece.

Preferably, the mask part 150 is a conductor and is grounded, and the mask part may be disposed to cover the upper surface of the recessed portion 110a of the ground electrode. That is, the mask unit 150 may be arranged in alignment with the opening of the truncated surface of the ground electrode. The main opening 111 of the mask unit 150 may allow the main dielectric barrier discharge to be locally generated along the first direction. In the closed region of the mask portion 150, no main dielectric barrier discharge is generated. In addition, in the open region of the mask portion 150, a main dielectric barrier discharge is generated. Accordingly, the workpiece 164 may have a processed area and an untreated area along the first direction.

In the gas provided through the auxiliary opening 153, the active gas formed in the main opening may move in the first direction by a dielectric barrier discharge, thereby suppressing a decrease in space selectivity. The gas provided through the auxiliary opening 153 may provide a pressure difference in a first direction, and may provide a higher pressure than a region in which the main opening is formed.

The first gas provided through the main gas distributor 181 and the second gas provided through the

auxiliary gas distributors

182 and 183 may be the same and may be atmospheric. However, the gas provided through the main opening may be converted into the active gas by the dielectric barrier discharge.

According to a modified embodiment of the present invention, the mask unit 150 may be disposed adjacent to the lower portion of the object 164 without contacting the ground electrode 110. In this case, the mask unit 150 may have various two-dimensional patterns. Meanwhile, when the workpiece and the mask unit 150 are fixed, the linear dielectric barrier plasma apparatus may move to form a two-dimensional pattern on the workpiece.

9A to 9I, the separator film plasma processing apparatus 100 of the secondary battery includes a ground electrode 110 including a depression extending in a first direction and electrically grounded; A power electrode 120 buried in the recessed portion of the ground electrode, part of which is exposed to the outside, and an AC voltage is applied and extends in the first direction; A dielectric barrier portion 130 disposed in contact with the power electrode and covering the exposed portion of the power electrode and extending in the first direction; A susceptor (162) facing the power electrode and extending in the first direction and grounded; The separator film 164 including the main opening 151 and the auxiliary opening 153 and supported by the susceptor extending in the first direction and the exposed portion of the power electrode are disposed in a first region facing each other. A mask unit 150 for spatially controlling the plasma density to selectively plasma-process the separator film according to the position in the first direction; And

auxiliary gas distributors

182 and 183 providing a gas to the auxiliary opening 153 to provide a pressure distribution along the first direction.

The object 164 may be a separator film of a secondary battery. The workpiece may be disposed on the susceptor (or roller) to move. A main dielectric barrier is formed in the first region, and a mask portion for spatially modulating the plasma density along the first direction is disposed in the first region. Therefore, the separator film may have a hydrophilic to-be-processed region in a line form extending next to each other. In order to increase the spatial selectivity of the plasma treatment, gas is provided on the workpiece through the auxiliary opening. Accordingly, the plasma treatment is performed only at the main opening.

Referring again to FIGS. 9A-9I, an atmospheric dielectric discharge plasma processing method includes providing a transport means 162 supported and electrically grounded while transporting a workpiece 164; Transferring the workpiece 164 through the transfer means under atmospheric pressure; Providing alternating current power to a power electrode (120) buried in the ground electrode (110) and partially exposed; By placing the mask portion 150 on the dielectric barrier portion 130 covering the exposed portion of the power electrode 120, selectively the dielectric according to the position of the workpiece between the transfer means and the exposed portion of the power electrode Performing a barrier discharge plasma treatment; And controlling the pressure according to the position by providing gas to the auxiliary opening 153 disposed around the main opening 151 where the plasma discharge is performed in the mask unit.

Gas may be supplied to the exposed portion of the power electrode through the ground electrode 110. The plasma hydrophilizes the workpiece, and the gas may include at least one of air, oxygen, nitrogen, hydrogen, and argon. The object 164 may be a separator film of a secondary battery. The gas provided through the main opening and the gas provided through the auxiliary opening may be the same and may be atmospheric. However, the gas provided through the main opening may be converted into the active gas by the dielectric barrier discharge.

When the power electrode has a triangular pillar shape, an auxiliary dielectric discharge may be generated between the ground electrode and the exposed portion of the power electrode (or the inclined surface of the power electrode). To this end, a second region may be formed between the ground electrode and the dielectric barrier portion, and a process gas may be supplied through the second region.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. You will understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

In the secondary battery comprising a negative electrode, a positive electrode, a separator, and an electrolyte solution,

And a hydrophilic treatment region and a non-hydrophilic treatment region of a plurality of periodic line pattern types hydrophilically treated with plasma by an atmospheric pressure dielectric barrier discharge on one or both surfaces of the separator.
According to claim 1,

The width of the non-hydrophilic treatment region is from 5 millimeters to 20 millimeters,

The width of the hydrophilic treatment region is from 5 millimeters to 20 millimeters,

Both sides of the separator is characterized in that the hydrophilic treatment region is disposed.
In the manufacturing method of a secondary battery,

Performing selective surface treatment so as to have a hydrophilic treatment region and a non-hydrophilic treatment region in the form of a plurality of periodic line patterns selectively selectively exposed to one surface of the separator by atmospheric pressure dielectric barrier discharge;

Laminating the hydrophilized membrane and an electrode to provide an electrode assembly;

Sealing the electrode assembly with a sealing member and injecting an electrolyte through an electrolyte injection hole of the sealing member.
The method of claim 3, wherein

The selective surface treatment is performed using a plasma formed only in the openings using a conductive mask mounted on a dielectric barrier discharge linear source and having a plurality of openings spaced apart from each other,

The membrane support portion for supporting the separator is a conductor material,

Separator support portion is a method of manufacturing a secondary battery, characterized in that the conductive mask is maintained at the same potential.
The method of claim 4, wherein

And selectively injecting an inert gas into the closed region of the conductive mask to prevent the plasma formed in the opening from diffusing into the closed region of the conductive mask.
The method of claim 4, wherein

The conductive separator support part is a manufacturing method of a secondary battery, characterized in that the roller (roller) in contact with the separator.
The method of claim 6,

And the roller and the conductive mask are grounded.