KR102672541B1 - Anode material, method of manufacturing the same, and secondary battery including the same - Google Patents

Abstract

A negative electrode material capable of reducing the risk of explosion, a method for manufacturing the same, and a secondary battery including the same are disclosed. This negative electrode material includes a negative electrode conductor plate and a plurality of negative electrode active materials. A plurality of the negative electrode active materials are attached to one surface of the negative electrode conductor plate through a bonding member, and plate-shaped negative electrode material flakes are arranged in an upright position inside the negative electrode active material.

Description

Anode material, manufacturing method thereof, and secondary battery including the same {ANODE MATERIAL, METHOD OF MANUFACTURING THE SAME, AND SECONDARY BATTERY INCLUDING THE SAME}

The present invention relates to a negative electrode material, a method of manufacturing the same, and a secondary battery including the same, and more specifically, to a negative electrode material capable of reducing the risk of explosion, a method of manufacturing the same, and a secondary battery including the same.

Currently, as the information age becomes more sophisticated, mobile electronic devices owned by individuals are widely used. These mobile electronic devices inevitably require batteries to operate.

In the past, primary batteries such as manganese batteries and alkaline batteries, which were used once and discarded when discharged, were mainly used, but recently, instead of primary batteries, which are disadvantageous in terms of environmental pollution and cost, after discharge, they are used again. Secondary batteries that are rechargeable and can be used repeatedly are widely used.

These secondary batteries generally consist of a positive electrode material, a negative electrode material, an electrolyte, and a separator. Among these, the anode and cathode materials are the most core materials that determine the capacity, lifespan, and charging speed of the battery. The anode material determines the capacity and average voltage of the battery as a lithium-ion source, and the cathode material determines the charging speed and lifespan.

When charging, lithium ions in the positive electrode material move toward the negative electrode material, and these lithium ions are stored in the negative electrode active material. When discharging, the lithium ions in the negative electrode active material move toward the positive electrode material.

At this time, if the negative electrode active material stores lithium ions, the volume increases, and if it releases lithium ions, the volume decreases. If the number of charging and discharging increases, the risk of explosion due to damage to the secondary battery increases. I do it.

Republic of Korea Patent Publication No. 10-2022-0167669

Accordingly, the problem to be solved by the present invention is to provide a negative electrode material that can reduce the risk of secondary battery explosion.

Another problem to be solved by the present invention is to provide a method for manufacturing such an anode material.

Another problem that the present invention aims to solve is to provide a secondary battery containing such an anode material.

A negative electrode material according to an exemplary embodiment of the present invention for solving this problem includes a negative electrode conductor plate and a plurality of negative electrode active materials. A plurality of the negative electrode active materials are attached to one surface of the negative electrode conductor plate through a bonding member, and plate-shaped negative electrode material flakes are arranged in an upright position inside the negative electrode active material.

As an example, a plurality of the negative electrode active materials may be in close contact with or adhere to each other.

In one embodiment, the negative electrode conductor plate and the negative electrode active material may be adhered to each other.

As an example, materials constituting the plate-shaped negative electrode material flakes may include silicon, tin, antimony, and graphene.

As an example, the joining member may be a mixture of polymer resin and a conductor or a conductive polymer resin.

As an example, the polymer resin may be any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.

As an example, the negative electrode active material may include a plurality of adhesive layers parallel to the normal direction of the negative electrode conductor plate.

As an example, the negative conductor plate may include copper.

A method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention includes forming a slurry by mixing plate-shaped negative electrode material flakes, a binder, and a solvent, coating the slurry on a release paper to form a coating layer, and heat drying. curing the coating layer, forming a plate by separating the release paper, forming a bonded body by attaching a plurality of plates using an adhesive or an adhesive, and forming a bonded body at intervals smaller than the thickness of the bonded body. It includes cutting to form a negative electrode active material, and attaching the negative electrode active material to a negative electrode metal plate.

As an example, in the step of attaching the negative electrode active material to the negative electrode metal plate, the cut surface of the negative electrode active material may be attached to the negative electrode metal plate.

As an example, in the step of attaching the negative electrode active material to the negative electrode metal plate, the negative electrode active material is attached to the negative electrode such that at least a portion of the cutting surface of the plurality of negative electrode active materials is adhered to the surface of the negative electrode material plate. It can be attached to a metal plate.

As an example, in the step of attaching the negative electrode active material to the negative electrode metal plate, the negative electrode active material may be attached to the negative electrode metal plate so that the plurality of negative electrode active materials are in close contact or adhesion to each other.

As an example, in the step of attaching the negative electrode active material to the negative electrode metal plate, the negative electrode active material is attached to the negative electrode metal plate using a bonding member, and the bonding member is a mixture of polymer resin and conductor. It could be something.

At this time, the polymer resin may be any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.

As an example, the binder may be any one of styrene butadiene rubber (SBR), carboxy methylcellulose (CMC), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE).

As an example, the solvent may include water or NMP (N-Methyl-2-Pyrrolidone).

A secondary battery according to an embodiment of the present invention includes the negative electrode material, positive electrode material, electrolyte, and separator described above. The anode material is disposed to be spaced apart from the cathode material. The electrolyte is disposed between the cathode material and the anode material. The separator is disposed in the electrolyte to separate the anode and cathode.

As an example, the positive electrode material includes a plate-shaped positive conductor plate and a positive electrode active material layer. The positive electrode active material layer is formed on one surface of the positive conductor plate and includes a positive electrode active material, a conductive material, and a binder.

As an example, _the positive electrode active material _is at _least one of _{LiCoO 2} , LiNiCoMnO ₂ , LiMnO ₄ , LZO-NCM _{( LiNi} You can.

As an example, the conductive material may be at least one of carbon black, acetylene black, vapor grown carbon fiber (VGCF), CNT, and graphene.

According to the cathode material according to the present invention, the plate-shaped cathode material flakes are arranged in an upright form and expand in the plane direction of the cathode conductor plate (i.e., the direction perpendicular to the normal), thereby reducing the risk of explosion. You can.

In addition, when the negative electrode active material includes a plurality of adhesive layers parallel to the normal direction of the negative electrode conductor plate, it can suppress SEI (Solid Electrolyte Interphase), a thin film created on the surface of the negative electrode material when charging for the first time. Not only can dendrites be suppressed, but the expansion of the negative electrode active material can be accommodated by the elasticity of the adhesive layer.

1 is a cross-sectional view showing a negative electrode material according to an exemplary embodiment of the present invention.
FIG. 2 is a flowchart showing a method of manufacturing a negative electrode material according to an exemplary embodiment of the present invention shown in FIG. 1.
FIG. 3 is a cross-sectional view showing step S150 shown in FIG. 2.
FIG. 4 is a cross-sectional view showing step S160 shown in FIG. 2.
Figure 5 is a cross-sectional view showing the negative electrode active material formed as a result of Figure 4.
FIG. 6 is a cross-sectional view showing step S170 shown in FIG. 2.
FIG. 7 is a schematic diagram of a secondary battery including the anode material shown in FIG. 1.

Since the present invention can be subject to various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components. In the attached drawings, the dimensions of the structures may be exaggerated compared to the actual size for clarity of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component without departing from the scope of the present invention.

The terms used in this application are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. In addition, the meaning of A and B being 'connected' or 'combined' means that in addition to A and B being directly connected or combined, another component C is included between A and B and A and B are connected or combined. It includes

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings they have in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No. Additionally, in the scope of the patent claims for the method invention, the order of each step may be changed unless each step is clearly bound to the order.

Additionally, configurations individually described in each embodiment may be applied to other embodiments.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

1 is a cross-sectional view showing a negative electrode material according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the negative electrode material (N) according to an exemplary embodiment of the present invention includes a negative electrode conductor plate (NNP) and a plurality of negative electrode active materials (NAL).

The negative conductor plate (NNP) may include copper.

A plurality of the negative electrode active material (NAL) is attached to one side (NNP) of the negative electrode conductor plate through a bonding member 100, and a plate-shaped negative electrode material flake 1110 is placed inside the negative electrode active material (NAL). arranged in the form As an example, the material constituting the plate-shaped negative electrode material flake 1110 may include silicon.

Graphite and silicon are widely used as anode materials for lithium-ion batteries. Silicon can store nearly 10 times more lithium ions than graphite, making silicon a very efficient anode material. However, when silicon stores lithium ions, its volume expands, and there is a risk of explosion due to a short circuit.

In the present invention, a plate-shaped anode material flake made of silicon is erected and expands in the X direction, so even if expansion occurs, the risk of short circuit can be prevented and the risk of explosion can be reduced. That is, when the expansion is large in the Y direction, the expansion is in the direction of the anode material P as shown in FIG. 7, increasing the risk of short circuit. However, in the present invention, the expansion is large in the X direction, thereby reducing the risk of explosion.

As an embodiment, the plate-shaped negative electrode material flake 1110 made of silicon may be a general silicon flake, or alternatively, the plate-shaped negative electrode material flake 1110 made of silicon may be subjected to plasma treatment to form a plurality of holes. It is also possible to form porous plate-shaped negative electrode material flakes 1110. Additionally, the porous plate-shaped negative electrode material flake 1110 may be coated using carbon, tin, iron, nickel, aluminum, chromium, etc. These coatings can inhibit the expansion of silicone. In addition, during plasma treatment, large and small diameter through holes are formed through primary treatment with high energy and secondary treatment with low energy, and through the coating process described above, large diameter through holes are filled with coating material. , small-diameter through-holes may be formed internally as cavities to accommodate expansion.

These negative electrode material flakes 1110 may contain tin, antimony, graphene, etc. in addition to silicon.

As an example, the negative conductor plate (NNP) and the negative electrode active material (NAL) may be bonded to each other by the bonding member 100.

Meanwhile, the joining member 100 may be a mixture of polymer resin and a conductor or a conductive polymer resin. As an example, the polymer resin may be any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber. The conductor may be a metal or non-metal that conducts electric current.

Meanwhile, a plurality of the negative electrode active materials (NAL) may be in close contact with or adhere to each other. That is, in the process of bonding the negative electrode active material (NAL) to the negative electrode conductor flake (NNP), when the bonding member 100 permeates between the negative electrode active material (NAL), the negative electrode active material (NAL) ) are adhered to each other, and when the bonding member 100 does not penetrate between the negative electrode active materials (NAL), the negative electrode active materials (NAL) are adhered to each other.

Additionally, the anode active material (NAL) may include a plurality of adhesive layers 1200 parallel to the normal direction of the anode conductor plate (NNP). Therefore, when charging for the first time, SEI (Solid Electrolyte Interphase), a thin film created on the surface of the anode material, can be suppressed. That is, when the adhesive layer 1200 is not present, SEI covers the entire area, but when the adhesive layer 1200 is present, SEI is not generated on the surface of the adhesive layer 1200, so SEI is formed in small pieces. , it can easily be separated from the negative electrode active material (NAL). In addition, the adhesive layer 1200 can not only suppress dendrites, but also accommodate expansion of the negative electrode active material due to the elasticity of the adhesive layer 1200.

Hereinafter, a method of manufacturing such an anode material will be described with reference to FIG. 2.

FIG. 2 is a flowchart showing a method of manufacturing a negative electrode material according to an exemplary embodiment of the present invention shown in FIG. 1.

Referring to Figures 1 and 2, according to the method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention, first, plate-shaped negative electrode material flakes 1110, a binder, and a solvent are mixed to form a slurry (step S110). As an example, the plate-shaped anode material flakes 1110 are arranged in an upright position. As an example, the material constituting the plate-shaped negative electrode material flake 1110 may include silicon. Additionally, the binder may be any one of styrene butadiene rubber (SBR), carboxy methylcellulose (CMC), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE). Additionally, the solvent may include water or NMP (N-Methyl-2-Pyrrolidone).

Thereafter, the slurry is coated on release paper to form a coating layer (step S120). In this case, a process of pressing the coating layer and laying the plate-shaped negative electrode material flake 1110 on the release paper may be further performed. This process may be performed after pre-curing the coating layer.

Afterwards, heat drying is performed to harden the coating layer (step S130).

Afterwards, the release paper is separated to form a plate (step S140).

Thereafter, a plurality of plates are attached using an adhesive or adhesive to form a joint (step S150).

FIG. 3 is a cross-sectional view showing step S150 shown in FIG. 2.

Referring to FIG. 3, flat plate-shaped negative electrode material flakes 1110 are arranged on a plurality of plates 1100 separated from the release paper. These multiple plates 1100 are attached through adhesive.

Referring again to FIG. 2, the negative electrode active material is formed by cutting the bonded body at intervals smaller than the thickness of the bonded body (step S160).

FIG. 4 is a cross-sectional view showing step S160 shown in FIG. 2.

Referring to FIG. 4 , a bonded body in which a plurality of plates 1100 in which plate-shaped negative electrode material plates 1110 are laid down are attached using an adhesive 1200 is cut along a cutting line CL in the thickness direction. At this time, the spacing (d) between the cutting lines (CL) is smaller than the thickness (t) of the bonded body.

Figure 5 is a cross-sectional view showing the negative electrode active material formed as a result of Figure 4. In this way, when the negative electrode active material 2000 cut to a width smaller than the thickness of the bonded body is laid down, the plate-shaped negative electrode material flakes 1110 inside the negative electrode active material 2000 remain in an erect state, and the adhesive layer 1200 also It can be seen that it is formed vertically.

Referring again to FIG. 2, the negative electrode active material is attached to the negative electrode metal plate (step S170).

FIG. 6 is a cross-sectional view showing step S170 shown in FIG. 2.

Referring to FIG. 6, in the step of attaching the negative electrode active material 2000 to the negative electrode metal plate (NNP), the cut surface of the negative electrode active material 2000 is attached to the negative electrode metal plate (NNP). can do. At this time, the negative electrode active material 2000 is attached to the negative electrode material plate (NNP) so that at least a portion of the cutting surface of the plurality of negative electrode active materials 2000 is adhered to the surface of the negative electrode material plate (NNP). You can. In this way, a plurality of negative electrode active materials 2000 are attached to form a negative electrode active material layer (NAL).

Meanwhile, in the step of attaching the negative electrode active material 2000 to the negative electrode metal plate (NNP), the negative electrode active material 2000 is attached to the negative electrode metal plate so that the plurality of negative electrode active materials 2000 are in close contact with or adhere to each other. Can be attached to plate (NNP).

Meanwhile, the negative electrode active material 2000 may be attached to the negative electrode metal plate (NNP) using the joining member 100. For example, the joining member 100 may be a mixture of polymer resin and a conductor or conductive polymer resin.

At this time, the polymer resin may be any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.

FIG. 7 is a schematic diagram of a secondary battery including the anode material shown in FIG. 1.

Referring to FIG. 7, the secondary battery according to an exemplary embodiment of the present invention includes a negative electrode material (N) manufactured by the method described above, and a positive electrode material (P) disposed to be spaced apart from the negative electrode material (N). , an electrolyte (EL) disposed between the anode material (N) and the anode material (P), and a separator (SM) disposed in the electrolyte (EL) to separate the anode and the cathode.

For example, the positive electrode material (P) is a plate-shaped positive conductor plate (PMP), and a positive electrode material formed on one surface of the positive conductor plate (PMP), and a positive electrode active material, a conductive material, and a binder are mixed. It may include an active material layer (PAL).

For _example , the positive electrode active material may _be at least one _of LiCoO ₂ , LiNiCoMnO ₂ , LiMnO _{4 ,} LZO-NCM _{( LiNi}

For example, the conductive material may be at least one of carbon black, acetylene black, vapor grown carbon fiber (VGCF), CNT, and graphene.

For example, the positive conductor plate (PMP) may include aluminum.

As described above, according to the cathode material according to the present invention, the plate-shaped cathode material flakes are arranged in an upright form, so that they expand in the plane direction of the cathode conductor plate (i.e., in the direction perpendicular to the normal line), thereby increasing the risk of explosion. can be reduced.

Although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, those skilled in the art or those skilled in the art will understand the spirit of the present invention as described in the patent claims to be described later. It will be understood that the present invention can be modified and changed in various ways without departing from the technical scope.

1000: Conjugate
1100: Plate 1110: Plate-shaped anode material flake
1200: Adhesive layer 2000: Anode active material
N: cathode material P: anode material
NNP: Negative conductor plate PMP: Positive conductor plate
PAL: positive electrode active material layer NAL: negative electrode active material layer
EL: Electrolyte SM: Separator

Claims (20)

negative conductor plate; and
A plurality of negative electrode active materials are attached to one surface of the negative conductor plate through a joining member,
Inside the negative electrode active material, plate-shaped negative electrode material flakes are arranged in an upright position,
The negative electrode active material is a negative electrode material characterized in that it includes a plurality of adhesive layers parallel to the normal direction of the negative electrode conductor plate.
According to claim 1,
A negative electrode material characterized in that a plurality of the negative electrode active materials are in close contact with or adhered to each other.
According to claim 1,
A negative electrode material, wherein the negative electrode conductor plate and the negative electrode active material are adhered to each other.
According to claim 1,
A negative electrode material, characterized in that the material constituting the plate-shaped negative electrode material flake is at least one of silicon, tin, antimony, and graphene.
According to claim 1,
The anode material is characterized in that the joining member is a mixture of a polymer resin and a conductor or a conductive polymer resin.
According to clause 5,
A negative electrode material characterized in that the polymer resin is any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.
delete According to claim 1,
The negative electrode material is characterized in that the negative electrode conductor plate contains copper.
Forming a slurry by mixing plate-shaped negative electrode material flakes, a binder, and a solvent;
Forming a coating layer by coating the slurry on release paper;
curing the coating layer by performing heat drying;
forming a plate by separating the release paper;
Forming a bonded body by attaching a plurality of plates using an adhesive or adhesive;
forming a negative electrode active material by cutting the conjugate at intervals smaller than the thickness of the conjugate; and
Attaching the negative electrode active material to the negative electrode metal plate;
A method of manufacturing an anode material comprising.
According to clause 9,
In the step of attaching the negative electrode active material to the negative electrode metal plate,
A method of manufacturing a negative electrode material, characterized in that the cutting surface of the negative electrode active material is attached to the negative electrode material metal plate.
According to claim 10,
In the step of attaching the negative electrode active material to the negative electrode metal plate,
A method of manufacturing a negative electrode material, characterized in that attaching the negative electrode active material to a negative electrode material metal plate so that at least a portion of the cutting surface of the plurality of negative electrode active materials is adhered to the surface of the negative electrode material metal plate.
According to claim 11,
In the step of attaching the negative electrode active material to the negative electrode metal plate,
A method of manufacturing a negative electrode material, characterized in that attaching the negative electrode active material to a negative electrode metal plate so that the plurality of negative electrode active materials are in close contact with or adhere to each other.
According to clause 9,
In the step of attaching the negative electrode active material to the negative electrode metal plate,
Attaching the negative electrode active material to the negative electrode metal plate using a joining member,
A method of manufacturing a negative electrode material, wherein the joining member is a mixture of a polymer resin and a conductor or a conductive polymer resin.
According to claim 13,
A method of manufacturing a negative electrode material, wherein the polymer resin or conductive polymer resin includes any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.
According to clause 9,
A method of manufacturing a negative electrode material, wherein the binder is one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), PVDF (Polyvinylidene fluoride), and PTFE (Polytetrafluoroethylene).
According to clause 9,
A method of producing a negative electrode material, wherein the solvent includes water or NMP (N-Methyl-2-Pyrrolidone).
The anode material according to any one of claims 1 to 6 and claim 8;
a positive electrode material disposed to be spaced apart from the negative electrode material;
An electrolyte disposed between the cathode material and the anode material; and
a separator disposed in the electrolyte to separate the anode and the cathode;
A secondary battery containing.
According to claim 17,
The cathode material is,
A plate-shaped anode conductor plate; and
A positive electrode active material layer formed on one surface of the positive conductor plate and comprising a mixture of a positive electrode active material, a conductive material, and a binder;
A secondary battery comprising:
According to clause 18,
The positive electrode active material is a _secondary material _, characterized in that at _least one of _{LiCoO 2} , LiNiCoMnO ₂ , LiMnO ₄ , LZO-NCM _{( LiNi} battery.
According to clause 18,
A secondary battery, wherein the conductive material is at least one of carbon black, acetylene black, vapor grown carbon fiber (VGCF), CNT, and graphene.

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