KR102653055B1 - Re-arranged stratified carbon material, preparing method of the same, and secondary battery including the same - Google Patents

Abstract

The present application includes the steps of preparing a mixed solution in which a layered structure carbon material and a polymer binder are dissolved and heat treating the mixed solution to produce a re-arranged layered structure carbon material, wherein the rearranged layered structure carbon The material relates to a method of manufacturing a rearranged layered structure carbon material in which the layered structure carbon material is formed by self-assembly and rearrangement through the heat treatment.

Description

Rearranged layered structure carbon material, manufacturing method thereof, and secondary battery including the same {RE-ARRANGED STRATIFIED CARBON MATERIAL, PREPARING METHOD OF THE SAME, AND SECONDARY BATTERY INCLUDING THE SAME}

The present application relates to a rearranged layered structure carbon material, a manufacturing method thereof, and a lithium secondary battery comprising the same.

Recently, with the development of the electronics industry, miniaturization and weight reduction of electronic equipment have become possible, and the use of portable electronic devices is increasing. As the need for secondary batteries with high energy density has increased as a power source for such portable electronic devices, research on lithium secondary batteries is actively underway. In addition, lithium-ion batteries, which are used as batteries for electric vehicles, are used in short-distance driving vehicles due to physical limitations (maximum energy density ~250 Wh/kg).

Lithium metal has an excellent theoretical energy density of 3,860 mAh/g and a very low standard hydrogen electrode (SHE) of -3.045 V, making it possible to implement high-capacity, high-energy-density batteries. Recently, lithium-sulfur and lithium-ion batteries have been developed. -As interest in air batteries increases, it is being actively researched as an anode active material for lithium secondary batteries.

However, when lithium metal is used as the negative electrode of a lithium secondary battery, the lithium metal reacts with electrolyte, impurities, lithium salts, etc. to form a passive layer (Solid Electrolyte Interphase, SEI), and this passive layer causes local current density differences. When charging, it promotes the formation of dendrite by lithium metal, and it gradually grows during charging and discharging, causing an internal short circuit between the anode and cathode. In addition, dendrites have a mechanically weak part (bottle neck), forming dead lithium that loses electrical contact with the current collector during discharge, thereby reducing battery capacity, shortening cycle life, and improving battery stability. has a negative impact on

In addition, the passivation layer is thermally unstable and may gradually collapse due to increased electrochemical and thermal energy when charging and discharging of the battery continues or, especially, when stored at high temperature in a fully charged state. Due to the collapse of this passivation layer, a side reaction in which the exposed lithium metal surface reacts directly with the electrolyte solvent and decomposes continues to occur, which increases the resistance of the cathode and reduces the charging and discharging efficiency of the battery. In addition, when forming the passivation layer, the solvent of the electrolyte is consumed, and the lifespan of the battery is shortened due to by-products and gases generated during various side reactions such as the formation and collapse of the passivation layer and decomposition of the electrolyte solution.

Due to the non-uniformity of the redox reaction of the lithium metal negative electrode and its reactivity with the electrolyte solution, lithium secondary batteries using lithium metal as the negative electrode have not yet been put into practical use.

To solve this problem, methods such as changing the composition of the electrolyte or introducing a separate protective layer on the lithium metal surface were used, but the stability of the lithium metal electrode was not effectively improved, and the capacity of the lithium ion host for stable storage of lithium metal was not found. Methods of using porous materials such as graphene have been attempted to increase There is.

Korean Patent Publication No. 10-2015-0005819, which is the background technology of the present application, relates to a graphene composite in which nanoparticles are dispersed, a manufacturing method thereof, and a secondary battery containing the same. Specifically, it relates to a graphene composite in which nanoparticles are dispersed, a method of manufacturing the same, and a secondary battery containing the same. Nano-sized chalcogen particles can be dispersed in graphene through a simple process, and through this, sulfur can be prevented from dissolving into the electrolyte during charging and discharging of existing lithium-sulfur batteries, thereby extending the life of the battery. It's about the fin complex. However, there is no mention of graphene composites in which sulfur nanoparticles are encapsulated by a porous polymer thin film.

The purpose of the present application is to solve the problems of the prior art described above and to provide an electrode for a secondary battery containing a rearranged layered structure carbon material.

In addition, the purpose of the present application is to provide a method for manufacturing the rearranged layered structure carbon material.

Additionally, the present application aims to provide a secondary battery including the electrode for the secondary battery.

However, the technical challenges sought to be achieved by the embodiments of the present application are not limited to the technical challenges described above, and other technical challenges may exist.

As a technical means for achieving the above-mentioned technical problem, the first aspect of the present application is an electrode for a secondary battery comprising a rearranged layered structure carbon material, wherein the rearranged layered structure carbon material includes a plurality of slits, , the slit stores metal ions therein when voltage is applied to grow the metal, providing an electrode for a secondary battery.

According to one embodiment of the present application, the internal spacing of the slit may be 0.3 nm to 8 nm, but is not limited thereto.

According to one embodiment of the present application, slits with an internal spacing of 0.3 nm to 8 nm may be 50% or more of the total number of slits, but are not limited thereto.

According to one embodiment of the present application, the rearranged layered structure carbon material may be rearranged by applying energy to the layered structure carbon material, but is not limited thereto.

According to one embodiment of the present application, the layered carbon material may be selected from the group consisting of graphene platelets, stratified carbon, and combinations thereof, but is not limited thereto. .

According to one embodiment of the present application, the rearranged layered structure carbon material may have a porous structure, but is not limited thereto.

According to one embodiment of the present application, the metal ion may be a lithium ion, but is not limited thereto.

According to one embodiment of the present application, the electrode for a secondary battery may be an electrode for a negative electrode, but is not limited thereto.

The second aspect of the present application includes preparing a mixed solution in which a layered carbon material is dissolved; And applying energy to the mixed solution to produce a re-arranged layered carbon material; A method for producing a rearranged layered structure carbon material, wherein the rearranged layered structure carbon material is formed by self-assembly and rearrangement of the layered structure carbon material by the applied energy. provides.

According to one embodiment of the present application, the mixed solution may further include a polymer binder, but is not limited thereto.

According to one embodiment of the present application, the polymer binder may be removed by the applied energy, but is not limited thereto.

According to one embodiment of the present application, a slit may be formed at the location of the removed polymer binder, but is not limited thereto.

According to one embodiment of the present application, the polymer binder is polyester, polyethylene vinyl acetate, polyester-polyethylene vinyl acetate copolymer, polyvinyl chloride, polyethylene, polypropylene, polybutadiene, polyolefin, polyvinyl chloride, polyvinyl acetate, Polyethylene terephthalate, polystyrene, polyethylene ketone, polyethylene terephthalate glycol, polyethylene imide, polyvinylidene fluoride, polytetrafluoroethylene, ethylene tetrafluoride, vinylidene fluoride copolymer, propylene hexafluoride, vinylidene fluoride/hexafluoride. Fluoropropylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamide imide, polyacrylic acid, polyvinyl alcohol, styrene butadiene rubber polymer, acrylonitrile-butadiene rubber, It may be selected from the group consisting of acrylonitrile-butadiene-styrene rubber, acrylate-based rubber, hydroxypropylmethylcellulose, sodium carboxymethylcellulose (CMC), and composite polymers containing one or more of these mixed together, but is not limited thereto.

According to one embodiment of the present application, applying the energy may be performed by a method selected from the group consisting of heat treatment, light irradiation, ultrasonic treatment, and combinations thereof, but is not limited thereto.

A third aspect of the present application provides a secondary battery including an electrode for a secondary battery according to the first aspect of the present application.

The fourth aspect of the present application includes preparing a mixed solution in which a layered structure carbon material and a polymer binder are dissolved and heat treating the mixed solution to produce a re-arranged layered structure carbon material, wherein the material The arranged layered structure carbon material provides a method of manufacturing a rearranged layered structure carbon material in which the layered structure carbon material is formed by self-assembly and rearrangement by the heat treatment.

According to one embodiment of the present application, the layered carbon material may include one selected from the group consisting of graphene platelets, stratified carbon, and combinations thereof, but is limited thereto. That is not the case.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a plurality of slits, but is not limited thereto.

According to one embodiment of the present application, the rearranged layered structure carbon material may have a porous structure, but is not limited thereto.

According to one embodiment of the present application, the polymer binder may be removed by the heat treatment, but it is not limited thereto.

According to one embodiment of the present application, the polymer binder is polyester, polyethylene vinyl acetate, polyester-polyethylene vinyl acetate copolymer, polyvinyl chloride, polyethylene, polypropylene, polybutadiene, polyolefin, polyvinyl chloride, polyvinyl acetate, polyethylene. Terephthalate, polystyrene, polyethylene ketone, polyethylene terephthalate glycol, polyethylene imide, polyvinylidene fluoride, polytetrafluoroethylene, ethylene tetrafluoride, vinylidene fluoride copolymer, propylene hexafluoride, vinylidene fluoride/hexafluoride Propylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamide imide, polyacrylic acid, polyvinyl alcohol, styrene butadiene rubber polymer, acrylonitrile-butadiene rubber, acrylic It may include, but is not limited to, those selected from the group consisting of ronitrile-butadiene-styrene rubber, acrylate-based rubber, hydroxypropylmethylcellulose, sodium carboxymethylcellulose (CMC), and composite polymers containing one or more of these. no.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a lithiophilic residual polymer binder, but is not limited thereto.

The fifth aspect of the present application provides a rearranged layered structure carbon material produced by the method according to the fourth aspect of the present application.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a plurality of slits, but is not limited thereto.

According to one embodiment of the present application, the rearranged layered structure carbon material may have a porous structure, but is not limited thereto.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a lithiophilic polymer binder, but is not limited thereto.

The sixth aspect of the present application provides a negative electrode for a lithium battery comprising a rearranged layered structure carbon material manufactured by the method according to the fourth aspect of the present application.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a plurality of slits, but is not limited thereto.

According to one embodiment of the present application, lithium ions may be concentrated inside the slit by accumulating an electric field when voltage is applied, but the present invention is not limited thereto.

A seventh aspect of the present application provides a lithium battery including a negative electrode for a lithium battery according to the sixth aspect of the present application.

The above-described means of solving the problem are merely illustrative and should not be construed as intended to limit the present application. In addition to the exemplary embodiments described above, additional embodiments may be present in the drawings and detailed description of the invention.

According to the above-described means of solving the problem of the present application, the rearranged layered structure carbon material manufactured by the method according to the present application includes a plurality of slits and has a porous structure, thereby suppressing the growth of lithium dendrites and preventing the growth of lithium dendrites during charging and discharging. It can buffer volume changes and secure a large lithium storage space, so it can be used as a negative electrode for lithium batteries that simultaneously improves battery performance, lifespan, and stability.

In addition, the rearranged layered structure carbon material according to the present disclosure includes a slit structure that is much narrower than the conventional slit structure, and metal ions, for example, lithium ions, are concentrated inside the slit by accumulating an electric field when voltage is applied. When stored, these metal ions can suppress dendritic lithium growth and induce the growth of dense metal, thereby realizing a stable and high-capacity lithium battery.

In addition, the negative electrode of the lithium battery according to the present disclosure can stably grow lithium metal using only carbon materials without using expensive metals such as transition metals, silver, gold, etc., and the grown lithium metal is concentrated in the lower part of the carbon material. By depositing it, a lithium battery with high capacity can be implemented.

In addition, the rearranged layered structure carbon material manufactured by the method according to the present disclosure contains a lithiophilic residual polymer binder, so that it can attract lithium ions during the lithium plating process, thereby providing high capacity and stability. It is possible to stably deposit lithium ions.

In addition, the method for manufacturing a rearranged layered structure carbon material according to the present disclosure is to self-assemble the layered structure carbon material using a simple method using heat treatment to produce a rearranged layered carbon material, thereby producing a manufacturing process. Since this can be simplified and manufactured in a short period of time, manufacturing costs can be lowered, leading to excellent convenience and economic efficiency. Accordingly, mass production is easy and can be usefully applied to various fields.

In addition, the electrode for a secondary battery according to the present disclosure, for example, a negative electrode for a lithium battery, includes a rearranged layered structure carbon material that includes a plurality of slits and has a porous structure, thereby suppressing the growth of lithium dendrites. Accordingly, the lithium battery according to the present disclosure including the negative electrode improves stability by preventing electrochemical driving performance deterioration and risk factors due to solid electrolyte interphase (SEI) and dendritic growth, thereby improving the coulombic efficiency of the battery. increases, and electrochemical properties such as charge/discharge capacity, lifespan, and rate can be improved.

In addition, the electrode for secondary batteries according to the present disclosure, for example, the negative electrode for lithium batteries, includes a rearranged layered structure carbon material that includes a plurality of slits and has a porous structure, thereby buffering volume changes during charging and discharging. Accordingly, the charge/discharge characteristics of the lithium battery according to the present disclosure including the negative electrode can be improved, thereby improving lifespan performance.

In addition, the electrode for secondary batteries according to the present disclosure, for example, the negative electrode for lithium batteries, includes a rearranged layered structure carbon material that includes a plurality of slits and has a porous structure, thereby securing a large space for accommodating lithium. Accordingly, the lithium battery according to the present disclosure including the negative electrode can solve the capacity limitation.

However, the effects that can be obtained herein are not limited to the effects described above, and other effects may exist.

Figure 1 is a schematic diagram and a manufacturing process diagram of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 2 is a schematic diagram showing the lithium metal storage mechanism of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 3 is an SEM photograph during the heat treatment process of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 4 is a TEM photo of a rearranged layered structure carbon material according to an example of the present application.
Figure 5 is an SEM photograph of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 6 is an SEM and TEM photograph of graphite according to a comparative example of the present application.
Figure 7 is a 3D schematic diagram of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 8 is a graph showing the results of structural analysis using a 3D schematic diagram of a rearranged layered structure carbon material according to an embodiment of the present application.
Figure 9 is a graph showing the results of analyzing the electrochemical characteristics of an electrode for a secondary battery according to an example of the present application.
Figure 10 is a graph showing the results of analyzing the electrochemical characteristics of an electrode for a secondary battery according to an example of the present application.
Figure 11 is a graph showing the results of analyzing the electrochemical characteristics of an electrode for a secondary battery according to an example of the present application.
Figure 12 is a cross-sectional image when lithium metal is deposited on an electrode for a secondary battery according to an embodiment of the present application.

Below, with reference to the attached drawings, embodiments of the present application will be described in detail so that those skilled in the art can easily implement them.

However, the present application may be implemented in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present application in the drawings, parts that are not related to the description are omitted, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout this specification, when a part is said to be “connected” to another part, this includes not only the case where it is “directly connected,” but also the case where it is “electrically connected” with another element in between. do.

Throughout this specification, when a member is said to be located “on”, “above”, “at the top”, “below”, “at the bottom”, or “at the bottom” of another member, this means that a member is located on another member. This includes not only cases where they are in contact, but also cases where another member exists between two members.

Throughout the specification of the present application, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

Throughout the specification of the present application, when a part “includes” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

As used herein, the terms "about", "substantially", etc. are used to mean at or close to the numerical value when the synthetic and material tolerances inherent in the stated meaning are presented, and to aid the understanding of the present application. It is used to prevent unscrupulous infringers from unfairly exploiting disclosures in which precise or absolute figures are mentioned. Additionally, throughout the specification herein, “a step of” or “a step of” does not mean “a step for.”

Throughout this specification, the term "combination thereof" included in the Markushi format expression means a mixture or combination of one or more components selected from the group consisting of the components described in the Markushi format expression, It means including one or more selected from the group consisting of.

Throughout this specification, description of “A and/or B” means “A or B, or A and B.”

Hereinafter, an electrode for a secondary battery containing the rearranged layered structure carbon material of the present application, a method of manufacturing the rearranged layered structure carbon material, and a secondary battery including the same will be described in detail with reference to embodiments and examples and drawings. Let's do it. However, the present application is not limited to these embodiments, examples, and drawings.

As a technical means for achieving the above-described technical problem, the first aspect of the present application is an electrode for a secondary battery comprising a rearranged layered structure carbon material, wherein the rearranged layered structure carbon material includes a plurality of slits, , the slit stores metal ions therein when voltage is applied to grow the metal, providing an electrode for a secondary battery.

In addition, the second aspect of the present application includes preparing a mixed solution in which a layered structure carbon material is dissolved; And applying energy to the mixed solution to produce a re-arranged layered carbon material; A method for producing a rearranged layered structure carbon material, wherein the rearranged layered structure carbon material is formed by self-assembly and rearrangement of the layered structure carbon material by the applied energy. provides.

Figure 1 is a schematic diagram and a manufacturing process diagram of a rearranged layered structure carbon material according to an embodiment of the present application.

Since the rearranged layered structure carbon material according to the present application is a layered structure of two or more layers, it is formed as a flat planar structure on the surface of a metal layer such as lithium, so that it can flatten the potential distribution on the surface of the metal electrode and suppress the growth of dendritic lithium. It is possible to prevent deterioration of the metal layer containing lithium.

In addition, the electrode for secondary batteries according to the present invention can stably grow metals such as lithium using only carbon materials without using expensive metals such as transition metals, silver, gold, etc., and the grown lithium metal can be grown on the lower part of the carbon material. By being concentrated and deposited, a lithium battery with high capacity can be implemented.

The rearranged carbon material according to the present disclosure includes a plurality of slits. The slit is different from the micropores included in known carbon materials reported previously.

Specifically, the plurality of slits according to the present application have a slit structure that is much narrower than the pores of a conventional carbon material with a general porous structure. These pores are too large for metal ions to pass through, be stored, or accumulate. Accordingly, the spacing within the plurality of slits according to the present application may be 1 nm or less.

In addition, the plurality of slits according to the present application have a slit structure that is wider than the graphene layer spacing (about 0.3 nm or less) that occurs due to the internal spacing between the graphene layers of known graphite. Metal ions are generally larger than the graphene layer gap and therefore cannot be stored or accumulated in the graphene layer gap. Accordingly, the internal spacing of the plurality of slits according to the present application may be 0.3 nm or more.

Referring to Figure 8 (E) of the present application, it can be seen that the gap between graphene layers is about 0.3 nm or less, which indicates the size of the micropores contained within the graphite.

That is, the internal spacing of the plurality of slits according to the present application may be 0.3 nm to 8 nm, and accordingly, metal ions can be stored or accumulated inside the slits, and further, the metal can grow. The internal spacing of the slit is, for example, 0.3 nm to 7 nm, 0.3 nm to 6 nm, 0.3 nm to 5 nm, 0.3 nm to 4 nm, 0.3 nm to 3 nm, 0.3 nm to 2 nm, 0.3 nm to 0.3 nm. It may be 1 nm, 0.3 nm to 0.9 nm, 0.3 nm to 0.8 nm, 0.3 nm to 0.7 nm, preferably 0.3 nm to 0.6 nm, but is not limited thereto. The slit has a very narrow gap of 0.3 nm to 0.6 nm, thereby inducing a strong internal electric field and stably accumulating lithium in the slit.

When voltage is applied to the electrode for the secondary battery, an electric field is accumulated inside the slit, and metal ions are stored and concentrated inside the slit, suppressing the growth of dendritic lithium and inducing the growth of dense lithium, creating a stable and high capacity lithium battery. It can be implemented. This process is shown in Figure 2.

According to one embodiment of the present application, slits with an internal spacing of 0.3 nm to 8 nm may be 50% or more of the total number of slits, but are not limited thereto. As previously described, the slit is a concept that must be distinguished from the interlayer gap of graphite. The slits may be 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more of the total number of slits, but are not limited thereto.

The rearranged layered structure carbon material may be rearranged by applying energy to the layered structure carbon material, and the layered structure carbon material includes graphene platelets, stratified carbon, and these. It may be selected from a group consisting of combinations, but is not limited thereto.

The graphene platelet refers to a form in which graphene is stacked in a disordered form.

In the graphene platelet, three of the four outermost electrons of carbon form fully or partially sp ² hybrid orbitals to form a strong covalent σ bond, and the remaining one electron forms a π bond with other surrounding carbon. It has a hexagonal honeycomb lattice structure. The carbon material layer having the sp ² bond as described above is highly resistant to chemical reactions and can physically block the reaction with the electrolyte and buffer volume changes during charging and discharging.

In addition, the rearranged graphene platelet according to the present disclosure is a layered structure of two or more layers of graphene, so it is formed as a flat planar structure on the surface of a metal layer containing lithium to flatten the potential distribution on the surface of the lithium metal electrode. , it can suppress the growth of dendritic lithium and prevent deterioration of the metal layer containing lithium.

The stacked carbon has a structure in which graphene is combined, and may have an interlayer distance that is 2 to 3 times longer than the 0.3 nm, which is the interlayer distance of general graphite, but is not limited thereto.

According to the above-described means of solving the problem of the present application, the rearranged layered structure carbon material manufactured by the method according to the present application includes a plurality of slits and has a porous structure, thereby suppressing the growth of lithium dendrites and preventing the growth of lithium dendrites during charging and discharging. It can buffer volume changes and secure a large lithium storage space, so it can be used as a negative electrode for lithium batteries that simultaneously improves battery performance, lifespan, and stability.

Figure 2 is a schematic diagram showing the lithium metal storage mechanism of a rearranged layered structure carbon material according to an embodiment of the present application.

The rearranged layered structure carbon material manufactured by the method according to the present disclosure accumulates an electric field by including very narrow gaps (slits), leading to the effect of lithium ions being concentrated inside the slits. Accordingly, lithium dentrite growth is suppressed because surface areas of very narrow crevices have only small amounts of lithium, which are insufficient to form dendrites, and at the same time, lithium can be deposited more uniformly. In addition, compared to a typical graphite electrode, there is a wider lithium accommodation space and lithium can be deposited at high density, so it can be used as a negative electrode for a lithium battery that overcomes capacity limitations.

According to one embodiment of the present application, the rearranged layered structure carbon material may have a porous structure, but is not limited thereto.

The porous structure can accumulate lithium ions by concentrating the electric field generated by concentration of electrons. Additionally, the porous structure can reduce relative current density by increasing the specific surface area, and is more effective in physically blocking reaction with the electrolyte and buffering changes in the volume of the battery. Additionally, the movement of lithium ions is easy.

The plurality of slits are created in the process of rearranging the layered carbon material.

Specifically, energy is applied to the mixed solution in which the layered carbon material is dissolved to produce a re-arranged layered carbon material. In this process, the applied energy causes the layered carbon material to self-assemble (self-assembly). assembly) and rearranged.

According to one embodiment of Bonhwon, the mixed solution may further include a polymer binder, and as the polymer binder is removed by the energy, the plurality of slits may be formed at the location where the polymer binder was present.

Specifically, when energy is applied to a carbon material including a pore with a polymer binder, the layered carbon material is compressed, the size of the pore decreases, and even the remaining pores are filled with the polymer binder. At the same time, the polymer binder is removed by the above energy, ultimately forming a rearranged layered carbon material containing multiple slits.

The energy can be applied by various methods such as heat treatment, light irradiation, and ultrasonic treatment, and is preferably performed by heat treatment.

After the polymer binder is removed by the heat treatment, some polymer binder may remain on the graphene surface, but is not limited to this.

According to one embodiment of the present application, the polymer binder is polyester, polyethylene vinyl acetate, polyester-polyethylene vinyl acetate copolymer, polyvinyl chloride, polyethylene, polypropylene, polybutadiene, polyolefin, polyvinyl chloride, polyvinyl acetate, polyethylene. Terephthalate, polystyrene, polyethylene ketone, polyethylene terephthalate glycol, polyethylene imide, polyvinylidene fluoride, polytetrafluoroethylene, ethylene tetrafluoride, vinylidene fluoride copolymer, propylene hexafluoride, vinylidene fluoride/hexafluoride Propylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamide imide, polyacrylic acid, polyvinyl alcohol, styrene butadiene rubber polymer, acrylonitrile-butadiene rubber, acrylic It may include, but is not limited to, those selected from the group consisting of ronitrile-butadiene-styrene rubber, acrylate-based rubber, hydroxypropylmethylcellulose, sodium carboxymethylcellulose (CMC), and composite polymers containing one or more of these. no.

According to one embodiment of the present application, the rearranged layered structure carbon material may include a lithiophilic residual polymer binder, but is not limited thereto.

The rearranged layered structure carbon material manufactured by the method according to the present application contains a lithiophilic residual polymer binder and can attract lithium ions during the lithium plating process, thereby uniformly releasing lithium ions at high capacity. It can be deposited stably.

In other words, the rearranged layered structure carbon material manufactured by the method according to the present application concentrates lithium ions into a microporous structure and very narrow slits by a strong internal electric field, resulting in solid electrolyte interphase (SEI) and dendritic growth. By improving stability by preventing electrochemical driving performance degradation and risk factors, the coulombic efficiency of the battery is increased, and it can be used as a negative electrode of a lithium battery with improved electrochemical properties such as charge/discharge capacity, lifespan, and rate.

In addition, the method for manufacturing a rearranged layered structure carbon material according to the present disclosure is to self-assemble the layered structure carbon material using a simple method using heat treatment to produce a rearranged layered carbon material, thereby producing a manufacturing process. Since this can be simplified and manufactured in a short period of time, manufacturing costs can be lowered, leading to excellent convenience and economic efficiency. Accordingly, mass production is easy and can be usefully applied to various fields.

A third aspect of the present application provides a secondary battery including an electrode for a secondary battery according to the first aspect of the present application.

Regarding the secondary battery of the third aspect of the present application, detailed description of parts overlapping with the first and second aspects of the present application has been omitted. However, even if the description is omitted, the battery described in the first and second aspects of the present application The content can be equally applied to the third aspect of the present application.

The secondary battery may be a lithium battery, and the lithium battery may include a general lithium battery in which the electrolyte is liquid, as well as an all-solid-state battery in which the electrolyte is solid, but is not limited thereto.

The present invention will be described in more detail through the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present application.

[Example 1] Preparation of rearranged graphene platelets (Re-AG)

First, 200 mg of graphene flakes were placed in a conical tube containing 20 ml of acetone and dispersed.

Next, add adhesive material (Loctite, Loctite401) into the conical tube and shake. At this time, as the reaction occurs, it swells, and the conical tube is placed in a vacuum oven to dry.

After drying, the hardened material is broken with a hammer and pulverized with a ball mill.

Heat treatment is performed by CVD. The heat treatment conditions were sequentially 120°C for 10 minutes, 400°C for 10 minutes, and 800°C for 5 minutes.

After heat treatment, the sample is obtained after sieving.

Figure 3 is an SEM photograph during the heat treatment process of rearranged graphene platelets according to an embodiment of the present application.

Through this, it was confirmed that the structure became porous depending on the degree of heat treatment.

FIG. 4 is a TEM image of rearranged graphene platelets according to an embodiment of the present application, FIG. 5 is an SEM image of rearranged graphene platelets according to an embodiment of the present application, and FIG. 6 is an image of the rearranged graphene platelets according to an embodiment of the present application. These are SEM and TEM photos of graphite according to the comparative example.

Through this, it was confirmed that empty space was formed when graphene was stacked during the manufacturing process of rearranged graphene platelets (Re-AG) according to the present application, and it was confirmed that the thickness between stacked graphene was less than 1 nm. there was.

In addition, it was confirmed that rearranged graphene platelets (Re-AG), which are distinct from graphite, were manufactured.

[Comparative example]

A half-cell (in the form of copper foil, separator, and lithium foil) made by combining copper foil and lithium foil without Re-AG casting as a general coin cell structure was used as a comparative example.

[Experimental Example 1]

Figure 7 is a 3D schematic diagram of rearranged graphene platelets according to an embodiment of the present application.

Specifically, to analyze the structure of the rearranged graphene platelets (Re-AG) according to Example 1, a 3D schematic diagram was constructed using a SCANNING TRANSMISSION ELECTRON MICROSCOPY (STEM) image.

Through this, it was confirmed that the rearranged graphene platelets (Re-AG) according to the present application include a plurality of slits.

Figure 8 is a graph showing the results of analyzing the structure of rearranged graphene platelets according to an embodiment of the present application using a 3D schematic diagram.

Specifically, (A) in Figure 8 is a graph showing Xrd data, (B) in Figure 8 is a graph showing XPS data, (C) in Figure 8 is a graph showing Raman data, and (D) in Figure 8 ) is a graph showing saxs data, and (E) in FIG. 8 is a graph showing the results of gap distribution calculation using the 3D schematic diagram.

XRD analysis data shows that although it has a similar interplanar distance and structure to graphite, it was found that Re-AG has additional space based on the pick around 45 degrees of Re-AG.

XPS analysis data confirmed that nitrogen functional groups remained when graphene platelets were manufactured using a cycanogen-based adhesive material.

Based on Raman analysis data, it was confirmed that Re-AG has more doping and defect sites than general graphite.

Saxs data showed that Re-AG had quantitatively more narrow gaps than graphite.

Based on Figure 7, the numerical distribution of gaps and pore widths of Re-AG is summarized and expressed graphically.

[Experimental Example 2]

Figure 9 is a graph showing the results of analyzing the electrochemical characteristics of a negative electrode for a lithium battery according to an example of the present application.

Figure 9 (A) is a schematic diagram of a half cell using rearranged graphene platelets (Re-AG) according to Example 1 of the present application, and (B) is the corresponding 1 mAh/cm ² This is a graph measuring the Coulombic efficiency and voltage profile when a current density of 1 mA/cm ² is applied to the capacity, and (C) is when a current density of 4 mA/cm ² is applied to the corresponding capacity of 4 mAh/cm ² This is a graph measuring the coulombic efficiency and voltage profile, (D) is a graph analyzing the impedance after manufacturing the half cell, and (E) is 1 mAh/cm of the half cell manufactured according to an example and comparative example of the present application. This is a graph measuring the Coulombic efficiency when 5 mA/cm ² and 10 mA/cm ² current densities are applied to the corresponding capacity of ² .

Referring to FIG. 9, the anode for a lithium battery using the rearranged graphene platelets (Re-AG) according to Example 1 has a high coulombic efficiency of more than 95% and a long cycle life of more than 200 cycles at a relatively harsh current density. I was able to confirm what I was seeing. In other words, it was confirmed that it exhibited superior coulombic efficiency and lifespan than the bare sample. In addition, it was confirmed that the cathode according to the present disclosure showed a lower lithium deposition overvoltage than the bare sample. This suggests that the rearranged graphene platelets (Re-AB) according to Example 1 provide a host for lithium ions, enabling stable deposition, and providing high efficiency and long lifespan by reducing unwanted side reactions.

Figure 10 is a graph showing the results of analyzing the electrochemical characteristics of a negative electrode for a lithium battery according to an example of the present application.

Specifically, a symmetric cell was manufactured using lithium metal as the anode and the rearranged graphene platelets (Re-AG) according to Example 1 as the cathode.

Figure 10 (A) is a schematic diagram of the symmetric cell, and Figure 10 (B) is a graph showing cycling performance when a current density of 1 mA/cm ² is applied to the corresponding capacity of 1 mAh/cm ² , (C) in 10 is a graph measuring the coulombic efficiency when a current density of 1 mA/cm ² is applied to the corresponding capacity of 4 mAh/cm ² .

Figure 11 is a graph showing the results of analyzing the electrochemical characteristics of a negative electrode for a lithium battery according to an example of the present application.

Specifically, a full cell was manufactured using NCM as the anode and rearranged graphene platelets (Re-AG) according to Example 1 as the cathode.

Figure 11 (A) is a schematic diagram of the full cell, Figure 11 (B) is a graph measuring the capacity and voltage profile of the battery, and Figure 11 (C) is a graph showing the capacity retention and voltage profile of the battery. This is a graph measuring .

[Experimental Example 3]

Figure 12 is a cross-sectional image when lithium metal is deposited on a negative electrode for a lithium battery according to an embodiment of the present application.

Referring to FIG. 12, it was confirmed that lithium metal was densely formed and stably deposited on the lower part of the carbon material. Through this, unlike the conventional technology where lithium metal was stably deposited using expensive metals such as transition metals, silver, and gold, lithium metal can be stably deposited only with carbon materials without the use of expensive metals. I was able to confirm.

The description of the present application described above is for illustrative purposes, and those skilled in the art will understand that the present application can be easily modified into other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present application.

Claims (15)

In an electrode for a secondary battery containing a rearranged layered structure carbon material,
The rearranged layered structure carbon material includes a plurality of slits,
The slit includes storing metal ions inside the slit when a voltage is applied to grow the metal,
The internal spacing of the slit includes 0.3 nm to 8 nm,
Including that the slits having an internal spacing of 0.3 nm to 8 nm are more than 50% of the total number of slits,
Electrodes for secondary batteries.
According to claim 1,
The rearranged layered structure carbon material further includes an adhesive material,
During XPS analysis of the rearranged layered structure carbon material,
Including that a nitrogen functional group is observed by the adhesive material of the rearranged layered structure carbon material,
Electrodes for secondary batteries.
According to claim 1,
The slit is such that an electric field is induced inside the slit when a voltage is applied,
Electrodes for secondary batteries.
According to claim 1,
The rearranged layered structure carbon material is rearranged by applying energy to the layered structure carbon material,
Electrodes for secondary batteries.
According to claim 4,
The layered carbon material includes one selected from the group consisting of graphene platelets, stratified carbon, and combinations thereof,
Electrodes for secondary batteries.
According to claim 1,
The rearranged layered structure carbon material has a porous structure,
Electrodes for secondary batteries.
According to claim 1,
The metal ion includes lithium ions,
Electrodes for secondary batteries.
According to claim 1,
The electrode for a secondary battery is an electrode for a negative electrode.
Providing an adhesive material to a layered carbon material to prepare a mixed solution;
Drying the mixed solution and pulverizing it with a ball mill to produce a layered carbon material precursor including the layered carbon material and the adhesive material; and
Comprising the step of producing a re-arranged layered structure carbon material by applying energy to the layered structure carbon material precursor,
In the step of preparing the mixed solution, the gap between the adjacent layered carbon materials is reduced by the adhesive material,
In the step of manufacturing the rearranged layered structure carbon material, the adhesive material of the layered structure carbon material precursor includes compressing the layered structure carbon material of the layered structure carbon material precursor by the energy, and at the same time As the adhesive material evaporates, the layered carbon material self-assembles and rearranges, forming a plurality of slits.
Method for manufacturing rearranged layered carbon materials.
According to clause 9,
In the step of manufacturing the rearranged layered structure carbon material, the slit is formed at the position of the adhesive material evaporated by the energy,
Method for manufacturing rearranged layered carbon materials.
According to clause 9,
In the step of manufacturing the rearranged layered structure carbon material, some of the adhesive material of the layered structure carbon material precursor is not removed,
Method for manufacturing rearranged layered carbon materials.
According to clause 9,
The layered carbon material includes a plurality of graphene layers,
Including that the spacing between adjacent graphene layers of the layered carbon material is 0.6 nm to 0.9 nm,
Method for manufacturing rearranged layered structure carbon materials.
According to claim 10,
The adhesive material is polyester, polyethylene vinyl acetate, polyester-polyethylene vinyl acetate copolymer, polyvinyl chloride, polyethylene, polypropylene, polybutadiene, polyolefin, polyvinyl chloride, polyvinyl acetate, polyethylene terephthalate, polystyrene, and polyethylene ketone. , polyethylene terephthalate glycol, polyethylene imide, polyvinylidene fluoride, polytetrafluoroethylene, ethylene tetrafluoride, vinylidene fluoride copolymer, hexafluoropropylene, vinylidene fluoride/hexafluoropropylene copolymer, polyvinyl. Ridene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamide imide, polyacrylic acid, polyvinyl alcohol, styrene butadiene rubber polymer, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber. , acrylate-based rubber, hydroxypropylmethylcellulose, sodium carboxymethylcellulose (CMC), and composite polymers containing one or more mixtures thereof,
Method for manufacturing rearranged layered structure carbon materials.
According to clause 9,
Applying the energy is performed by a method selected from the group consisting of heat treatment, light irradiation, ultrasonic treatment, and combinations thereof,
Method for manufacturing rearranged layered structure carbon materials.
A secondary battery comprising the electrode for a secondary battery according to any one of claims 1 to 8.