KR102806180B1 - Method and apparatus for atomic layer deposition coating of electrode for secondary battery - Google Patents

Abstract

The present invention discloses an atomic layer deposition coating method for an electrode for a secondary battery. The atomic layer deposition coating method includes an electrode lamination roll preparation step of preparing an electrode in a roll unit by laminating it with a porous film; and an atomic layer deposition step of forming a coating layer on the surface of the electrode by repeatedly performing a process of installing the electrode lamination roll inside a sealed chamber and then supplying and removing a source gas or a purge gas inside the chamber.

Description

{Method and apparatus for atomic layer deposition coating of electrode for secondary battery}

The present invention relates to an atomic layer deposition coating method for a secondary battery electrode and an atomic layer deposition apparatus therefor.

As technology development and demand for mobile devices increase, the demand for rechargeable, miniaturized, and large-capacity secondary batteries is rapidly increasing. In addition, lithium secondary batteries with high energy density and voltage among secondary batteries are commercialized and widely used.

Lithium secondary batteries have a structure in which a non-aqueous electrolyte containing a lithium salt is impregnated into an electrode assembly with a porous separator interposed between a positive electrode and a negative electrode, each of which has an active material applied to a current collector. The positive electrode active material is mainly composed of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium composite oxide, etc., and the negative electrode oxide is mainly composed of a carbon-based material.

However, these lithium secondary batteries generally tend to have significantly reduced remaining capacity and recovery capacity when stored under high-temperature conditions. This is because the metal components of the active material, especially the positive electrode active material, are dissolved due to the action of the electrolyte under high-temperature conditions.

In other words, the cathode has a problem that the electrolyte decomposition is severe on the surface due to the high oxidation potential, which is accompanied by gas generation and cell expansion. In addition, the structure becomes unstable during the insertion and desorption of lithium ions, and the problem of metal components being dissolved and degraded from the electrode occurs. In particular, this phenomenon is more severe and occurs rapidly in high-energy active materials, causing a rapid decrease in the remaining capacity of the battery and a threat to safety.

Accordingly, methods of surface coating through vapor deposition or sputtering have been proposed to improve the electrode stability and safety of lithium-ion secondary batteries, but it is difficult for the coating methods to penetrate into the electrode and form a coating layer on the surface within the pores. To improve this drawback, atomic layer deposition has been proposed. Atomic layer deposition is a technology that suppresses the vapor reaction by time-divisionally injecting precursors and reactants using vapor-phase chemical deposition reaction, and precisely controls the thickness of the thin film through a self-control reaction that occurs on the surface of the substrate.

Coating using the atomic layer deposition method can be broadly divided into two methods: a method of coating active materials at the particle level and a method of coating an electrode formed by coating and drying an active material slurry.

When atomic layer deposition is performed on the active material particle itself, there is a problem that the coating layer formed on the particle surface acts as an insulating layer and restricts the movement of electrons. On the other hand, the method of coating the electrode has the advantage of minimizing the increase in cell resistance by not interfering with the movement of electrons because the coating is performed without interfering with the already formed conductive path.

Meanwhile, the current atomic layer deposition coating method can be divided into a time-division method and a space-division method. The time-division method is a method in which one or more sheet-shaped or 3D-structured substrates are loaded into a process chamber, and then source gas, purge gas, and reaction gas are sequentially injected into the process chamber according to the temporal order. On the other hand, the space-division method is mainly performed in a roll-to-roll method in which source gas, purge gas, and reaction gas are injected into spatially separated spaces in order to continuously perform atomic layer deposition coating on a roll-shaped film, and the film substrate is unwound and passed through the spaces where each gas exists sequentially.

For example, as illustrated in FIG. 1, a roll-to-roll type atomic layer deposition equipment (1) of the prior art is configured such that a plurality of rotating roller members (4) are arranged in a single row on both sides within a process space (3) partitioned by a partition means (2), and an electrode film (F) starting from an unwinding roller (5) installed outside the process space (3) enters the process space (3) and moves along the plurality of rotating roller members (4) so that an atomic layer deposition process is performed in a space-division manner, and is wound around a take-up roller (60) and discharged.

However, electrodes are produced in roll units of hundreds of meters or more. In order to apply the roll-to-roll atomic layer deposition method to such roll-unit electrodes, there is a difficulty in that the existing electrode production line must be significantly modified. In addition, while the electrode production speed is 50 to 100 meters per minute (50MPM to 100MPM), the roll-to-roll coating speed is 0.2 to 50 meters per minute (0.2MPM to 50MPM), which is difficult to achieve even for a substrate with low flexibility and thickness such as an electrode. It is difficult to improve the productivity of the final product with the roll-to-roll atomic layer deposition coating method with such a slow coating speed.

Accordingly, there is a need for the development of a new atomic layer deposition coating method and device that can improve the process efficiency and production efficiency of secondary battery electrodes.

Korean Patent Publication No. 10-2018-0027137 2018.03.14. NCD Co., Ltd.

The present invention has been created to solve the above-described problems, and an object of the present invention is to provide a method and device capable of performing atomic layer deposition coating without unwinding or rewinding an electrode roll instead of a conventional roll-to-roll process, thereby increasing process efficiency and production efficiency.

The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

According to one aspect of the present invention, there is provided a method for depositing an atomic layer on an electrode for a secondary battery, the atomic layer deposition coating method including: an electrode lamination roll preparation step of preparing an electrode in a roll unit by laminating it with a porous film; and an atomic layer deposition step of installing the electrode lamination roll inside a sealed chamber, and then repeatedly performing a process of supplying and removing a source gas or a purge gas inside the chamber to form a coating layer on the surface of the electrode.

The above electrode can be at least one of an anode and a cathode.

The above electrode can be formed by coating and drying an active material on a current collector.

In the above atomic layer deposition step, the material forming the coating layer may be at least one material selected from a metal oxide, a metal nitride, a metal oxynitride, a metal sulfide, a metal fluoride, a metal phosphate, and a lithium compound.

The material forming the above coating layer is a metal oxide, and the metal oxide may be ZrO ₂ , Al ₂ O ₃ , SiO ₂ , ZnO, TiO ₂ , SnO ₂ , MnO, HfO ₂ , CeO ₂ , V ₂ O ₅ or a mixture of two or more of these.

According to another aspect of the present invention, an atomic layer deposition apparatus for performing the above-described atomic layer deposition coating method may be provided, comprising: a reaction chamber providing an internal space in which the electrode lamination roll can be accommodated; a gas injection unit provided on one side of the reaction chamber and supplying a source gas or a purge gas into the reaction chamber; and a gas discharge unit provided on the other side of the reaction chamber and discharging the source gas or the purge gas to the outside from inside the reaction chamber.

The above reaction chamber may have an inner wall surface formed of a curved structure capable of making surface contact with the outer peripheral surface of the electrode roll.

At least one of the gas injection unit and the gas discharge unit may be provided so as to be separable from the reaction chamber.

The above reaction chamber may be provided in a cylindrical shape with both ends open, the gas injection unit may be coupled so as to be able to seal one side that is open in the reaction chamber, and the gas discharge unit may be coupled so as to be able to seal the other side that is open in the reaction chamber.

The gas injection unit may include an injection unit body coupled to one side of the reaction chamber; a first joint roll support member protruding from the center of one side of the injection unit body into the internal space of the reaction chamber; and a gas supply pipe provided on the other side of the injection unit body and extending to the outside of the reaction chamber.

The above injection unit body may include an inner disk forming one surface of the injection unit body, an outer disk forming the other surface of the injection unit body, and a buffer space that can temporarily accommodate gas as an empty space between the inner disk and the outer disk.

The inner disk may have a number of gas holes provided along the circumferential direction.

The electrode roll center rod is further provided to pass through the center of the electrode roll, and the first electrode roll support member may be provided as a socket type into which one end of the electrode roll center rod can be inserted.

The above gas discharge portion further includes a second laminated roll support member that protrudes from the center of the gas discharge portion into the internal space of the reaction chamber, and the second laminated roll support member may be provided as a socket type into which the other end of the electrode roll center rod can be inserted.

The above first laminated roll support member, the electrode roll center rod, and the second laminated roll support member are formed as a hollow structure, and ventilation holes may be provided on the outer circumferential surface of the electrode roll center rod.

According to one aspect of the present invention, by bonding an electrode and a porous film and allowing gas species for atomic layer deposition to permeate through pores secured through the porous film to perform atomic layer deposition on the surface of the electrode, it becomes possible to perform atomic layer deposition in roll units.

Accordingly, the atomic layer deposition coating time, cost, and space can be significantly reduced compared to the existing roll-to-roll atomic layer deposition process.

The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of the present invention; therefore, the present invention should not be interpreted as being limited to matters described in such drawings.
Figure 1 is a drawing schematically illustrating the configuration of a roll-to-roll atomic layer deposition device according to conventional technology.
FIG. 2 is a schematic diagram of the layered structure of a combined electrode and a porous film according to one embodiment of the present invention.
FIGS. 3 and 4 are drawings showing an electrode laminate roll according to one embodiment of the present invention.
FIGS. 5 and 6 are drawings illustrating the configuration of an atomic layer deposition device and an electrode roll installation process according to one embodiment of the present invention.
FIG. 7 is a process diagram for explaining a process of applying an atomic layer deposition coating to an electrode using an atomic layer deposition apparatus according to one embodiment of the present invention.
Fig. 8 is a drawing for explaining a modified example of the electrode roll center rod of Fig. 7.

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

A method for depositing an atomic layer on an electrode for a secondary battery according to one embodiment of the present invention includes an electrode lamination roll (20) preparation step and an atomic layer deposition step.

The above secondary battery electrode (21) may be at least one of a positive electrode and a negative electrode. That is, the atomic layer deposition coating according to the present invention may target both a positive electrode and a negative electrode.

Specifically, the electrode (21) may include a current collector and an active material layer provided on at least one surface of the current collector. The current collector is a conductive metal plate and is not particularly limited as long as it does not cause a chemical change in the battery. For example, the current collector may be copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, zinc, or the like, an aluminum-cadmium alloy, or the like.

The thickness of the entire collector is not particularly limited, but can be typically applied from 3 ㎛ to 500 ㎛.

And the above active material layer can be formed by applying a slurry obtained by mixing an active material, a binder, a conductive material, and a solvent to the surface of a current collector, and then drying and rolling.

In addition, the cathode active material may include one or a mixture of two or more selected from the group consisting of LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCoPO ₄ , LiFePO ₄ and LiNi _1-xyz Co _x M1 _y M2 _z O ₂ (M1 and M2 are each independently any one selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo, and x, y and z are each independently atomic fractions of oxide composition elements, 0≤x<0.5, 0≤y<0.5, 0≤z<0.5, 0<x+y+z<1). The cathode active material may be included in an amount of 80 to 99 wt% based on the total weight of the slurry.

And the negative active material may include, but is not limited to, carbon and graphite materials such as natural graphite, artificial graphite, expanded graphite, carbon fiber, non-graphitizable carbon, carbon black, carbon nanotubes, fullerene, and activated carbon; metals such as Al, Si, Sn, Ag, Bi, Mg, Zn, In, Ge, Pb, Pd, Pt, and Ti that can be alloyed with lithium and compounds containing these elements; composites of metals and their compounds with carbon and graphite materials; lithium-containing nitrides, etc.

The electrode lamination roll (20) preparation step is a process of laminating a porous film (22) on one or both sides of the electrode (21), winding it, and preparing it as a roll unit, as shown in FIGS. 2 to 4.

The joining of the electrode (21) and the porous film (22) means joining the porous film (22) to each other on the surface of the electrode (21). As will be described later, the porous film (22) is used as a means for permeating a reaction source gas or a purge gas. Since the porous film (22) is a part that must be easily removable after the atomic layer deposition coating is completed, it is preferable to simply attach the electrode (21) and the porous film (22) together rather than using a thermal bonding method or an adhesive when joining them.

The porous film (22) may preferably have a very large porosity for smooth permeation of gases, that is, the empty portion may occupy 50% to 90% of the total volume. The thickness of the porous film (22) may preferably be approximately twice the thickness of the electrode (21). This is in consideration of the size (diameter) of the electrode roll (20) that can be coated at one time, the breathability of the reaction source gas, the size of the reaction chamber (100), etc., but depending on other various environments, a porous film (22) having a thickness that is 0.5 to 1 or 3 times or more the thickness of the electrode (21) may also be used.

As an alternative to the above porous film (22), a porous body, a foam, a non-woven fabric, a sheet or web with excellent breathability, etc., which can pass gas and is flexible and can be rolled or unrolled together with the electrode (21), may be used instead.

For example, the electrode (21) and the porous film (22) can be prepared in roll units by using the rotating rollers of the existing electrode production line to be laminated and wound, as shown in FIG. 4. Hereinafter, the electrode (21) and the porous film (22) wound in roll units will be referred to as an electrode lamination roll (20). An electrode roll center rod (400) can be used as the core of the electrode lamination roll (20). As will be described in detail later, in addition to being used as the core, the electrode roll center rod (400) can also be used as a means for providing convenience in transporting and installing the electrode (21) and the porous film (22) after they are wound.

The atomic layer deposition step includes a process of forming a metal oxide coating layer on the surface of the electrode (21) by repeatedly performing the process of installing the electrode roll (20) inside a sealed chamber and then supplying and removing a source gas inside the chamber several times.

The conventional roll-to-roll atomic layer deposition coating method (see Fig. 1) can be said to be a continuous type that fills the chamber with a reaction source gas, exposes the surface of the substrate to be coated, and moves its position.

On the other hand, the atomic layer deposition coating method according to the present invention can be said to be a batch type in which the electrode lamination roll (20) is fixed in one position and the reaction source gas is introduced into a sealed chamber. In particular, the reaction source gases can smoothly penetrate through the pores secured through the porous film (22) portion of the electrode lamination roll (20) and be adsorbed on the surface of the electrode (21) even without releasing the electrode lamination roll (20).

Therefore, according to the atomic layer deposition coating method of the present invention, the coating process space can be significantly reduced, and atomic layer deposition coating can be performed on the surface of an electrode (21) with a sufficiently large area, thereby maximizing productivity. In addition, the electrode (21) that has undergone a batch-type atomic layer deposition process like the present invention has the advantage of being able to omit or reduce the existing high-temperature vacuum drying process (10 hours or more).

Additionally, the process of forming a metal oxide coating layer on the surface of the electrode (21) is briefly described below.

As mentioned, after installing the electrode lamination roll (20) inside the chamber, the reaction chamber (100) is sealed. Then, the reaction chamber (100) is depressurized by removing air through a pump connected to the gas discharge unit (300). At this time, the pressure is preferably between 0.1 Torr and 10 Torr. However, if an inert gas is blown into the reaction chamber (100) to replace the air introduced when installing the electrode lamination roll (20) with the inert gas, the pressure inside the reaction chamber (100) may be around 1 atm or higher. The inert gas may be Ar (argon) or nitrogen gas, which is the same as the excess removal gas described below. After the reaction chamber (100) reaches the desired process pressure or is filled with the inert gas, the reaction source gas and the purge gas are separately supplied at regular time intervals. That is, by repeating the process of 'supplying precursor material' -> 'removing excess' -> 'supplying reactant material' -> 'removing excess', the thickness of the atomic layer is gradually built up on the surface of the electrode (21) as desired. At this time, to remove the excess gas, Ar (argon) or nitrogen gas can be mainly used as an inert gas.

And the thickness of the atomic layer deposition coating layer is preferably 0.2 nm to 1 nm, and the metal oxide formed through the atomic layer deposition step may be ZrO ₂ , Al ₂ O ₃ , SiO ₂ , ZnO, TiO ₂ , SnO ₂ , MnO, HfO ₂ , CeO ₂ , V ₂ O ₅ or a mixture of two or more thereof. Of course, the material forming the atomic layer deposition coating layer may also be a metal nitride, a metal oxynitride, a metal sulfide, a metal fluoride, a metal phosphate, a lithium compound, etc. in addition to a metal oxide.

Next, an atomic layer deposition device (10) capable of smoothly performing the aforementioned atomic layer deposition coating method will be described in detail.

FIG. 5 and FIG. 6 are drawings illustrating the configuration of an atomic layer deposition device (10) and the process of installing an electrode lamination roll (20) according to one embodiment of the present invention, and FIG. 7 is a process diagram explaining the process of applying an atomic layer deposition coating to an electrode (21) using an atomic layer deposition device (10) according to one embodiment of the present invention.

Referring to FIGS. 5 and 6, an atomic layer deposition device (10) according to one embodiment of the present invention includes a reaction chamber (100), a gas injection unit (200), a gas discharge unit (300), and an electrode roll center rod (400).

The reaction chamber (100) is a structure that provides an internal space that can accommodate an electrode lamination roll (20). The reaction chamber (100) of the present embodiment has a cylindrical shape with both ends open, and has an inner wall surface formed of a curved structure that can make surface contact with the outer peripheral surface of the electrode lamination roll (20). (For reference, a part of the reaction chamber is cut out and illustrated in FIGS. 5 and 6 as a means of showing the inside of the reaction chamber.)

However, if the inner wall surface has a curved or cylindrical structure that surrounds the entire outer circumference of the electrode roll (20) as in this embodiment, the outer shape of the reaction chamber (100) does not necessarily have to be cylindrical.

The internal space of the above reaction chamber (100) can be sealed by combining the gas injection unit (200) and the gas discharge unit (300). At least one of the gas injection unit (200) and the gas discharge unit (300) can be provided to be separated from the reaction chamber (100). For example, the gas injection unit (200) or the gas discharge unit (300) can be provided to be separated or combined with the reaction chamber (100) in a hinge or force-fit manner.

First, looking at the gas injection unit (200), the gas injection unit (200) of the present embodiment includes an injection unit body (210), a first roll support member (230), and a gas supply pipe (220).

The injection unit body (210) can be coupled to one side of the reaction chamber (100), that is, to the opening on the left side of the reaction chamber (100) in FIG. 5. More specifically, the injection unit body (210) includes an inner disk (211) forming one side thereof, an outer disk (212) forming the other side thereof, and a buffer space (B1) corresponding to a space temporarily containing gas as an empty space between them.

The inner disk (211) may be provided in a circular shape corresponding to the inner diameter of the reaction chamber (100) and may be provided with a plurality of gas holes (211a) formed by perforating the inner disk (211). It is preferable that the plurality of gas holes (211a) are formed along the circumferential direction of the inner disk (211), i.e., along the circumferential direction corresponding to the rolled porous film (22).

In order to ensure smooth distribution of the supplied gas, the size and number of gas holes (211a) can be changed. In particular, in order to ensure uniform distribution of the supplied gas, the size and distribution of gas holes (211a) can be gradually changed from the center toward the surface of the reaction chamber (100).

The outer disk (212) can be exposed to the outside of the reaction chamber (100) apart from the inner disk (211) with a buffer space (B1) therebetween. A gas supply pipe (220) can be connected to the outer disk (212) so as to be coupled and uncoupled, and can communicate with the buffer space (B1).

And the precursor source gas reservoir (222), the reactant source gas reservoir (223), and the purge gas reservoir (225) provided outside the reaction chamber (100) can be connected to the gas supply pipe (220), respectively. Each of these can be supplied separately by time division by opening and closing a valve (not shown). Of course, although not shown, it is also possible to provide two or more gas supply pipes (220) and connect one reservoir to each gas supply pipe (220).

The buffer space (B1) is a space that temporarily accommodates a source gas or purge gas. The source gas or purge gas that enters through a gas supply pipe (220) having a relatively small diameter can be widely spread and diffused in the buffer space (B1). Then, when the buffer space (B1) is filled with the source gas or purge gas, its internal pressure increases, and accordingly, the source gas or purge gas can be discharged at a high speed through the gas holes (211a).

The first laminated roll support member (230) may be provided in a socket shape that protrudes from one side of the injection unit body (210), that is, the center of the inner disk (211), into the internal space of the reaction chamber (100). One end of the electrode roll center rod (400) may be inserted into the first laminated roll support member (230). For example, the electrode laminated roll (20) may be easily installed inside the reaction chamber (100) by forcefully fitting one end of the electrode roll center rod (400) into the first laminated roll support member (230) and forcefully fitting the other end of the electrode roll center rod (400) into the second laminated roll support member (330) to be described later.

Meanwhile, the gas discharge unit (300) is configured to discharge the source gas or purge gas inside the reaction chamber (100) to the outside and can be connected to the other side of the reaction chamber (100), that is, the opening on the right side of the reaction chamber (100) in FIG. 5.

The gas discharge unit (300) of the present embodiment can be provided symmetrically with the gas injection unit (200) described above. Specifically, the gas discharge unit (300) includes a discharge unit body (310), a gas discharge pipe (32), and a second joint roll support member (330).

The discharge unit body (310) includes an inner discharge disk (311), an outer discharge disk (312), and a second buffer space (B2), similar to the injection unit body (210) described above.

The inner discharge disk (311) may be provided in a circular shape corresponding to the inner diameter of the reaction chamber (100) and may be provided with a plurality of gas holes (311a) formed by perforating the inner discharge disk (311).

And the outer discharge disk (312) can be exposed to the outside of the reaction chamber (100) apart from the inner discharge disk (311) with the second buffer space (B2) therebetween. The gas discharge pipe (320) can be connected to the outer discharge disk (312) in a coupling and uncoupling manner. An exhaust pump (not shown) can be further coupled to at least one side of the gas discharge pipe (320). When the exhaust pump is in operation, the source gas or purge gas within the reaction chamber (100) can be quickly discharged to the outside of the reaction chamber (100) through the gas discharge pipe (320).

The second laminated roll support member (330) may be provided in a socket shape that protrudes from one side of the discharge unit body (310), that is, the center of the inner discharge disk (311), into the internal space of the reaction chamber (100). The second laminated roll support member (330) may be configured symmetrically to the first laminated roll support member (230). That is, the electrode laminated roll (20) may be supported by having the other end of the electrode roll center rod (400) inserted into the second laminated roll support member (330).

Hereinafter, with reference again to FIGS. 5 to 7, the atomic layer deposition coating process of a secondary battery electrode using an atomic layer deposition device (10) according to the present invention will be briefly summarized.

The electrode lamination roll (20) prepared in advance is installed inside the reaction chamber (100). At this time, as shown in FIG. 5, the gas discharge part (300) is raised to open the reaction chamber (100) and the electrode lamination roll (20) is pushed into the reaction chamber (100). More precisely, the electrode lamination roll (20) is pushed into the reaction chamber (100) until one end of the electrode roll center rod (400) is completely inserted into the first lamination roll support member (230). Then, as shown in FIG. 6, the gas discharge part (300) is lowered again to seal the reaction chamber (100). In this process, the second lamination roll support member (330) is fitted into the other end of the electrode roll center rod (400) so that the electrode lamination roll (20) can be fixed inside the reaction chamber (100).

Next, the process of precursor source gas supply -> purge gas supply (removal of precursor or not) -> reactant source gas supply -> purge gas supply (removal of excess semi-layer) is repeated a certain number of times to form a metal oxide coating layer of the desired thickness. At this time, the flow of the source gas or purge gas, as illustrated in FIG. 7, enters one surface of the electrode lamination roll (20) through the pores of the porous film (22) and exits the other surface of the electrode lamination roll (20). In particular, as described above, the reaction chamber (100) of the present embodiment has a curved structure in which the inner wall surrounds and contacts the outer peripheral surface of the electrode lamination roll (20), so that the source gas or purge gas discharged from the gas injection unit (200) can be concentrated on one surface of the electrode lamination roll (20) and smoothly introduced into the electrode lamination roll (20).

Next, the configuration of an atomic layer deposition device (10) according to another embodiment of the present invention will be described. The same reference numerals as in the above-described embodiment represent the same components, and duplicate descriptions of the same components will be omitted, and differences from the above-described embodiment will be mainly described.

Another embodiment of the present invention is to further improve the operational effect of the source gas or purge gas.

Another embodiment of the present invention has a difference from the above-described embodiment in that the first laminated roll support member (230), the electrode roll center rod (400), and the second laminated roll support member (330) are all provided as hollow structures so that they can communicate with the gas injection unit (200) and the gas discharge unit (300).

In addition, a plurality of vent holes (410) are further provided on the outer surface of the electrode roll center rod (400). According to this configuration, as illustrated in FIG. 8, the source gas or purge gas can enter the electrode roll center rod (400) and then exit again through the plurality of vent holes (410). For example, since the source gas cannot reach one surface of the electrode (21) closest to the electrode center rod (400), deposition may be difficult. However, in the case of the present embodiment, the source gas or purge gas can be supplied from the inside to the outside of the electrode center rod (400), so the above-mentioned problem can be solved.

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

Meanwhile, although terms indicating directions such as up, down, left, and right are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

10: Atomic layer deposition device 20: Electrode lamination roll
21: Electrode 22: Porous film
100: Reaction chamber 200: Gas injection unit
210: Injection body 211: Inner disc
211a: Gas hole 212: Outer disc
220: Gas supply pipe 230: First joint roll support member
300: Gas discharge part 310: Discharge part body
320: Gas discharge pipe 330: Second joint roll support member
400: Electrode roll center rod

Claims (15)

A method for depositing and coating an atomic layer on an electrode for a secondary battery,
An electrode roll preparation step of non-adhesively covering an electrode composed of a current collector and an active material layer applied to the surface of the current collector with a porous film, and then winding the electrode and the porous film together to form a roll;
An atomic layer deposition step of forming a coating layer on the surface of the electrode by repeatedly performing the process of supplying and removing a source gas or a purge gas within the chamber after installing the electrode roll inside a sealed chamber; and
An atomic layer deposition coating method, characterized by comprising a step of removing the porous film by releasing the electrode lamination roll after performing the atomic layer deposition step. In the first paragraph,
An atomic layer deposition coating method, wherein the electrode is at least one of an anode and a cathode. In the first paragraph,
The above electrode is an atomic layer deposition coating method characterized in that it is formed by coating and drying an active material on a current collector. In the first paragraph,
An atomic layer deposition coating method, characterized in that in the atomic layer deposition step, the material forming the coating layer is at least one material selected from metal oxide, metal nitride, metal oxynitride, metal sulfide, metal fluoride, metal phosphate, and lithium compound. In paragraph 4,
An atomic layer deposition coating method, characterized in that the material forming the coating layer is a metal oxide, and the metal oxide is ZrO ₂ , Al ₂ O ₃ , SiO ₂ , ZnO, TiO ₂ , SnO ₂ , MnO, HfO ₂ , CeO ₂ , V ₂ O ₅ or a mixture of two or more thereof. An atomic layer deposition apparatus for performing an atomic layer deposition coating method according to Article 1,
A reaction chamber providing an internal space capable of accommodating the above electrode roll;
A gas injection unit provided on one side of the reaction chamber and supplying a source gas or a purge gas into the reaction chamber; and
An atomic layer deposition apparatus characterized by including a gas discharge unit provided on the other side of the reaction chamber and discharging a source gas or a purge gas to the outside from inside the reaction chamber. In Article 6,
The above reaction chamber,
An atomic layer deposition device characterized by having an inner wall surface formed of a curved structure capable of making surface contact with the outer peripheral surface of the electrode roll. In Article 6,
An atomic layer deposition apparatus, characterized in that at least one of the gas injection unit and the gas discharge unit is provided so as to be separable from the reaction chamber. In Article 6,
The above reaction chamber is provided in a cylindrical shape with both ends open,
An atomic layer deposition device, characterized in that the gas injection unit is coupled so as to be able to seal one side that is open in the reaction chamber, and the gas discharge unit is coupled so as to be able to seal the other side that is open in the reaction chamber. In Article 6,
The above gas injection part,
An atomic layer deposition apparatus characterized by comprising: an injection unit body coupled to one side of the reaction chamber; a first roll support member protruding from the center of one side of the injection unit body into the internal space of the reaction chamber; and a gas supply pipe provided on the other side of the injection unit body and extending to the outside of the reaction chamber. In Article 10,
An atomic layer deposition apparatus, characterized in that the injection unit body includes an inner disk forming one surface of the injection unit body, an outer disk forming the other surface of the injection unit body, and a buffer space capable of temporarily accommodating gas as an empty space between the inner disk and the outer disk. In Article 11,
An atomic layer deposition device characterized in that a plurality of gas holes are provided along the circumferential direction in the inner disk. In Article 10,
It further includes an electrode roll center rod that is arranged to pass through the center of the above electrode roll,
An atomic layer deposition apparatus characterized in that the first joint roll support member is provided in a socket type into which one end of the electrode roll center rod can be inserted. In Article 13,
The above gas discharge portion further includes a second roll support member that protrudes from the center of the gas discharge portion into the internal space of the reaction chamber,
An atomic layer deposition apparatus characterized in that the second roll support member is provided in a socket type into which the other end of the electrode roll center rod can be inserted. In Article 14,
An atomic layer deposition apparatus characterized in that the first laminated roll support member, the electrode roll center rod, and the second laminated roll support member are formed as a hollow structure, and ventilation holes are provided on the outer peripheral surface of the electrode roll center rod.

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