Composite anode active material including a double layer and a method of manufacturing same

Patent metadata

Field	Value
Publication number	US-2025219059-A1
Application number	US-202418824437-A
Country	US
Kind code	A1
Filing date	Sep 4, 2024
Priority date	Dec 29, 2023
Publication date	Jul 3, 2025
Grant date	—

Abstract

A composite anode active material including a double layer and a method of manufacturing the same are disclosed. In coating the surface of carbon-based particles with a coating layer having high energy density, a buffer layer is formed between the carbon-based particles and the coating layer. Charge/discharge efficiency of an all-solid-state battery including the anode active material is thereby improved. The anode active material has a core including carbon-based particles, a buffer layer covering at least a portion of a surface of the core and including a carbide, and a coating layer covering at least a portion of a surface of the buffer layer and including a lithiophilic material.

First claim

What is claimed is:

1 . An anode active material, comprising:
a core comprising carbon-based particles; a buffer layer covering at least a portion of a surface of the core and comprising a carbide; and a coating layer covering at least a portion of a surface of the buffer layer and comprising a lithiophilic material.

2 . The anode active material of claim 1 , wherein the carbon-based particles comprise at least one selected from the group consisting of natural graphite, artificial graphite, or any combination thereof.

3 . The anode active material of claim 1 , wherein the carbide comprises silicon (Si) and carbon (C) according to SiC x , where 0<x≤1.

4 . The anode active material of claim 1 , wherein a thickness of the buffer layer is 1 nanometer (nm) to 20 nm.

5 . The anode active material of claim 1 , wherein the lithiophilic material comprises a metal or metalloid capable of forming an alloy with lithium, and wherein the metal or metalloid capable of forming an alloy with lithium comprises at least one selected from the group consisting of silicon (Si), gold (Au), platinum (Pt), palladium (Pd), silver (Ag), aluminum (AI), bismuth (Bi), tin (Sn), zinc (Zn), or any combination thereof.

6 . The anode active material of claim 1 , wherein the lithiophilic material comprises amorphous silicon (Si).

7 . The anode active material of claim 1 , wherein a crystallite size of the lithiophilic material is 2 nm to 11 nm.

8 . The anode active material of claim 1 , wherein a thickness of the coating layer is 10 nm to 300 nm.

9 . The anode active material of claim 1 , wherein a difference (d max −d min ) between a maximum value (d max ) of a thickness of the coating layer and a minimum value (d min ) of a thickness of the coating layer is 5 nm or less.

10 . The anode active material of claim 1 , wherein an amount of the coating layer is 10 weight percent (wt %) to 60 wt % based on a total weight of the anode active material.

11 . An all-solid-state battery, comprising:
an anode current collector; an anode active material layer disposed on the anode current collector, wherein the anode active material comprises:
(i) a core comprising carbon-based particles,
(ii) a buffer layer covering at least a portion of a surface of the core and comprising a carbide, and
(iii) a coating layer covering at least a portion of a surface of the buffer layer and comprising a lithiophilic material;
a solid electrolyte layer comprising a solid electrolyte and disposed on the anode active material layer; a cathode active material layer comprising a cathode active material and disposed on the solid electrolyte layer; and a cathode current collector disposed on the cathode active material layer.

12 . The all-solid-state battery of claim 11 , wherein, when a formation process is performed on the all-solid-state battery and a result thereof is represented as a graph where an x-axis is capacity expressed as milliampere-hours per gram mass (mAh/g) and a y-axis is voltage (V), no plateau is observed in a range where a state of charge (SoC) of the all-solid-state battery is 24% to 44%.

13 . The all-solid-state battery of claim 11 , wherein, when a formation process is performed on the all-solid-state battery and a result thereof is represented as a graph where an x-axis is capacity (mAh/g) and a y-axis is voltage (V), a slope of the graph is 1.7 or less but greater than 0.8 in a range where a state of charge (SoC) of the all-solid-state battery is 24% to 44%.

14 . A method of manufacturing an anode active material, the method comprising:
preparing carbon-based particles, a precursor of carbide, and a precursor of a lithiophilic material; forming a buffer layer provided to cover at least a portion of a surface of a core that comprises the carbon-based particles; and forming a coating layer provided to cover at least a portion of a surface of the buffer layer, wherein the buffer layer comprises carbide derived from the precursor of the carbide, and wherein the coating layer comprises the lithiophilic material derived from the precursor of the lithiophilic material.

15 . The method of claim 14 , wherein forming the buffer layer and forming the coating layer are performed using chemical vapor deposition (CVD).

16 . The method of claim 14 , wherein the carbide comprises silicon (Si) and carbon (C) according to SiC x , where 0<x≤1.

17 . The method of claim 14 , wherein the precursor of the carbide comprises silane gas and hydrocarbon gas.

18 . The method of claim 15 , wherein the lithiophilic material comprises amorphous silicon (Si).

19 . The method of claim 14 , wherein the precursor of the lithiophilic material comprises at least one selected from the group consisting of SiH 4 , Si 2 H 6 , Si 3 H 8 , SiCl 4 , SiHCl 3 , Si 2 Cl 6 , SiH 2 Cl 2 , SiH 3 Cl, or any combination thereof, where H is hydrogen and Cl is chlorine.

20 . The method of claim 15 , wherein forming the coating layer using chemical vapor deposition is performed at a temperature of 475° C. or less.

Assignees

• Hyundai Motor Co Ltd
• Kia Corp
• Nat Univ Pukyong Ind Univ Coop Found

Inventors

• Lee Yoon Kwang
• Kim Yun Sung
• Im Ga Hyeon
• Lee Kyu Joon
• Min Hong Seok
• Lee So Young
• Chae Su Jong
• Ko Min Seong
• Kim Jae Won
• Lee Jin Su

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title