Composite electrode particles coated with a silicon layer, a carbon layer, and a zinc oxide layer

Abstract

A composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer is provided. [Solution] A composite electrode particle used in an electrode of a solid or semi-solid battery includes a porous carbon particle 30 having a plurality of holes on its surface, a silicon layer 32 which is a continuous thin film covering the outer surface of the porous carbon particle, the silicon layer being formed by filling the holes of the porous carbon particle with the silicon material of the silicon layer, an amorphous carbon layer 36 which has a continuous structure and covers the outer periphery of the silicon layer, and a zinc oxide layer 37 which is a continuous thin film formed of a plurality of zinc oxide molecules and covers the outer periphery of the amorphous carbon layer. Even if the silicon layer expands due to the filling of lithium ions into the silicon layer, the zinc oxide layer protects the structure of the inner layer due to its good spreading ability. The outer surface of the zinc oxide layer is further covered with an aluminum oxide layer. The aluminum oxide layer is a continuous thin film formed of a plurality of aluminum oxide molecules.

Description

[Technical field]

[0001] The present invention relates to an electrode particle, and more particularly to a composite electrode particle coated with a silicon layer, a carbon layer and zinc oxide. [Background technology]

[0002] The battery is composed of a positive electrode and a negative electrode, the negative electrode mainly includes a negative electrode substrate and a negative electrode slurry layer coated on the negative electrode substrate, the negative electrode slurry layer includes a negative electrode slurry having a binder and a plurality of negative electrode particles. The negative electrode particles are mainly used in the negative electrode of solid or semi-solid batteries. The negative electrode particles have conductive properties or conductivity, which allow free electrons to move in the negative electrode slurry and prevent excessive energy consumption due to internal resistance, thereby achieving the purpose of effective electrical conduction. Summary of the Invention [Problem to be solved by the invention]

[0003] The negative electrode particles are distributed in the negative electrode slurry, and the outer surfaces of these negative electrode particles are covered with silicon particles. However, during the battery reaction process, when lithium ions enter the silicon particles and the volume of the silicon particles expands, the silicon particles can expand up to 400 times their original size, causing a large change in the volume of the entire negative electrode particle. This huge volume expansion damages the entire negative electrode particle and reduces the battery performance.

[0004] Therefore, the present inventors believed that the above-mentioned shortcomings could be improved, and after extensive research, they proposed a design that improves the volume expansion of the negative electrode particles, thereby enabling the negative electrode of conventional solid-state batteries to have higher battery performance, thereby further improving the performance of the battery.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer. [Means for solving the problem]

[0006] In order to solve the above problems, a composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer according to an embodiment of the present invention is used in an electrode of a solid or semi-solid battery, and the composite electrode particle is: Porous carbon particles having a plurality of holes on the surface thereof; a silicon layer covering an outer surface of the porous carbon particle, the silicon layer being a continuous thin film, the silicon material of the silicon layer filling the holes of the porous carbon particle; an amorphous carbon layer covering the outer periphery of the silicon layer, the amorphous carbon layer being a continuous structure formed of amorphous carbon, the amorphous carbon layer having good electrical conductivity, suppressing the expansion of the entire electrode particle, and preventing a situation in which the volume of the silicon layer expands excessively due to lithium ions being filled in the silicon layer, causing the composite electrode particle to burst; a zinc oxide layer covering the outer periphery of the amorphous carbon layer, the zinc oxide layer being a continuous thin film formed of a plurality of zinc oxide molecules, the zinc oxide layer being a continuous dense layer having good electrical conductivity and metallic hardness, and the zinc oxide layer having ductility and integrity. Effect of the Invention

[0007] The present invention has the following advantages: In the present invention, the outer periphery of the porous carbon particles is covered with a silicon layer, which suppresses the expansion of the overall volume of the composite electrode particles and prevents the composite electrode particles from expanding excessively and being damaged. In addition, the outer periphery of the silicon layer is further covered with an amorphous carbon layer, which has a suitable electrical conductivity, and thus suppresses the expansion of the composite electrode particles, and prevents the volume of the composite electrode particles from expanding excessively by filling the silicon layer with lithium ions. The outer periphery of the amorphous carbon layer is further covered with a zinc oxide layer, which has good electrical conductivity and a spreading ability similar to that of a metal, so that even if the silicon layer expands when lithium ions are filled into the silicon layer, the zinc oxide layer has good spreading ability to protect the structure of the inner layer. In this way, the present invention significantly reduces the crushing rate of the composite electrode particles by the above-mentioned multi-layer coating structure.

[0008] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view showing a composite electrode particle according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram of a porous carbon particle according to an embodiment of the present invention; [Diagram 3] 2 is a schematic diagram showing an electrode particle coated with carbon nanotubes in accordance with an embodiment of the present invention; [Figure 4] 1 is an application example showing a composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram showing a composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following examples, and can be modified as desired without departing from the spirit and scope of the present invention.

[0011] First, an example of a specific embodiment of a composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer according to the present invention will be described with reference to FIGS. 1 to 5. FIG.

[0012] The composite electrode particles coated with silicon particles, carbon layer and zinc oxide layer according to the present invention are mainly used in electrodes of solid or semi-solid batteries, especially in the negative electrode 10 of the solid or semi-solid battery. The negative electrode 10 includes a negative electrode substrate 11 for mounting the material of the negative electrode 10, and a negative electrode slurry layer 13 applied to the negative electrode substrate 11 (see FIG. 4). The negative electrode slurry layer 13 includes a negative electrode slurry 12 as a binder, and a plurality of composite electrode particles 40. The weight percentage of the total weight of the plurality of composite electrode particles 40 in the negative electrode slurry layer 13 is in the range of 90wt% to 99wt%. The particle size of the composite electrode particles 40 is in the range of 5μm to 12μm.

[0013] The composite electrode particle 40 is composed of the following elements (see FIG. 1):

[0014] The <porous carbon particles 30> have a size in the range of 5 μm to 10 μm, and have a plurality of holes 31 on the surface (see FIG. 2). The porous carbon particles 30 are made of graphite or the like.

[0015] The <silicon layer 32> covers the outer surface of the porous carbon particle 30. The silicon layer 32 is a continuous thin film formed of a plurality of silicon materials, i.e., a thin film having a smooth surface. The silicon materials of the silicon layer 32 fill the holes 31 of the porous carbon particle 30. The thickness of the silicon layer 32 is less than 15 nm. The weight ratio of the silicon layer 32 to the porous carbon particle 30 is in the range of 1:9 to 1:12.

[0016] The amorphous carbon layer 36 covers the outer periphery of the silicon layer 32. The amorphous carbon layer 36 is a continuous structure formed of amorphous carbon, that is, a film layer having a smooth surface. The radial thickness of the amorphous carbon layer 36 is in the range of 10 nm to 20 nm. The amorphous carbon layer 36 has a suitable electrical conductivity, so that it can suppress the expansion of the entire electrode particles and prevent the electrode particles from bursting due to excessive volume expansion caused by filling the silicon layer 32 with lithium ions. The amorphous carbon of the amorphous carbon layer 36 is hard carbon or soft carbon formed by sintering deesterification of an organic resin system, or hard carbon or soft carbon formed by sintering deesterification of an organic carbohydrate.

[0017] During the reaction process of the battery, when lithium ions enter the silicon layer 32 and the volume of the silicon layer 32 expands, the silicon layer 32 may expand up to 400 times its original size, which causes a large change in the volume of the composite electrode particle 40. In order to prevent the silicon layer 32 from expanding too much and destroying the composite electrode particle 40, the silicon layer 32 is surrounded by the amorphous carbon layer 36 having a continuous structure, thereby achieving a double-layer protective effect and preventing the composite electrode particle 40 from being damaged.

[0018] A zinc oxide (ZnO) layer 37 covers the outer periphery of the amorphous carbon layer 36. The zinc oxide layer 37 is a continuous thin film formed of a plurality of zinc oxide molecules, i.e., a film layer having a smooth surface, and the whole forms the composite electrode particle 40. The radial thickness of the zinc oxide layer 37 is in the range of 8 nm to 12 nm. The zinc oxide layer 37 is a continuous dense layer having good electrical conductivity and metal hardness, and has good ductility and integrity, so that it can protect the structure of the inner layer, maintain the integrity of the composite electrode particle 40, and prevent breakage.

[0019] The present invention further includes a plurality of carbon nanotubes (CNTs) 42 that cover the outer periphery of the composite electrode particle 40, forming a carbon nanotube-covered electrode particle 45 (see FIG. 3). Each of the carbon nanotubes 42 has a length of less than 5 μm.

[0020] Carbon nanotubes are very good conductive materials and form a wool-like structure when attached to the composite electrode particles 40. The carbon nanotubes 42 are used to increase electronic conductivity and conduct electrons on the composite electrode particles 40. Carbon nanotubes have extremely high electrical conductivity, and lithium ions pass through the carbon nanotubes 40 and are conducted between different composite electrode particles 40 of the electrode, thereby increasing the electrical conductivity of the entire electrode. The weight ratio of the total weight of the carbon nanotubes 42 to the weight of the composite electrode particles 40 is in the range of 1:99 to 0.2:99.8.

[0021] FIG. 5 is a schematic diagram showing a composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to another embodiment of the present invention. The composite electrode particle 40 further includes an aluminum oxide (Al2O3) layer 38 that coats the outer periphery of the composite electrode particle 40. The aluminum oxide layer 38 is a continuous thin film formed of a plurality of aluminum oxide molecules, i.e., a film layer having a smooth surface, and coats the outer surface of the zinc oxide layer 37 of the composite electrode particle 40. The radial thickness of the aluminum oxide layer 38 is less than 5 nm. The aluminum oxide layer 38 can increase the electrical conductivity and electrolyte wettability of the composite electrode particle 40. The outer surface of the aluminum oxide layer 38 is further coated with the plurality of carbon nanotubes 42 to form an electrode particle 45 that entirely coats the carbon nanotubes.

[0022] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means devised in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0023] 10 negative electrode 11 Negative substrate 12 Anode slurry 13 Negative electrode slurry layer 30 Porous carbon particles 31 holes 32 Silicon layer 36 Amorphous carbon layer 37 Zinc oxide layer 38 Aluminum oxide layer 40 Composite electrode particles 42 Carbon nanotubes 45 Electrode particles coated with carbon nanotubes

Claims

1. A composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer, which is used in an electrode of a solid or semi-solid battery, Porous carbon particles having a plurality of holes on the surface thereof; a silicon layer covering an outer surface of the porous carbon particle, the silicon layer being a continuous thin film; an amorphous carbon layer covering the outer periphery of the silicon layer, the amorphous carbon layer being a continuous structure formed of amorphous carbon, the amorphous carbon layer having good electrical conductivity, suppressing the expansion of the entire electrode particle, and preventing a situation in which the volume of the silicon layer expands excessively due to lithium ions being filled in the silicon layer, causing the composite electrode particle to burst; a zinc oxide layer coating the outer periphery of the amorphous carbon layer, the zinc oxide layer being a continuous thin film formed of a plurality of zinc oxide molecules, the zinc oxide layer being a continuous dense layer having good electrical conductivity and metallic hardness, and having ductility and integrity.

2. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer as claimed in claim 1, characterized in that the particle size of the porous carbon particles ranges between 5 μm and 10 μm.

3. 2. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 1, wherein the silicon layer has a thickness of less than 15 nm.

4. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 1, characterized in that the weight ratio of the silicon layer and the porous carbon particles is in the range of 1:9 to 1:

12.

5. 2. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer as claimed in claim 1, wherein the radial thickness of the amorphous carbon layer is in the range of between 10 nm and 20 nm.

6. 2. The composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer according to claim 1, characterized in that the amorphous carbon of the amorphous carbon layer is selected from hard carbon or soft carbon formed by sintering deesterification of an organic resin system, or hard carbon or soft carbon formed by sintering deesterification of an organic carbohydrate.

7. 2. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 1, characterized in that the radial thickness of the zinc oxide layer is in the range of between 8 nm and 12 nm.

8. 2. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 1, wherein the composite electrode particle is used in a negative electrode of a solid or semi-solid battery.

9. The composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer according to claim 1, further comprising a plurality of carbon nanotubes (CNTs) coating the outer periphery of the composite electrode particle, thereby forming an electrode particle coated with the carbon nanotubes.

10. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer as described in claim 9, characterized in that each of the carbon nanotubes has a length of less than 5 μm and forms a wool-like structure when attached to the composite electrode particle, and the multiple carbon nanotubes are used to increase electronic conductivity.

11. The composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer according to claim 9, wherein the weight ratio of the total weight of the carbon nanotubes to the weight of the composite electrode particle is in the range of 1:99 to 0.2:99.

8.

12. The aluminum oxide (Al ２ O ３ 9. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 1, further comprising an aluminum oxide layer, the aluminum oxide layer being a continuous thin film formed of a plurality of aluminum oxide molecules, and coating an outer surface of the zinc oxide layer of the composite electrode particle.

13. 13. The composite electrode particle coated with a silicon layer, a carbon layer and a zinc oxide layer according to claim 12, characterized in that the radial thickness of the aluminum oxide layer is less than 5 nm.

14. The composite electrode particle coated with a silicon layer, a carbon layer, and a zinc oxide layer as described in claim 12, further comprising a plurality of carbon nanotubes coating the outer surface of the aluminum oxide layer, thereby forming an electrode particle coated with carbon nanotubes.

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