Negative electrode active material, method for preparing the same and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-2023088432-A1
Application number	US-202117908064-A
Country	US
Kind code	A1
Filing date	Mar 12, 2021
Priority date	Mar 13, 2020
Publication date	Mar 23, 2023
Grant date	—

Abstract

A negative electrode active material for a lithium secondary battery, a lithium secondary battery including the same, and a method for preparing the negative electrode active material is disclosed. The negative electrode active material includes a porous carbon coating layer self-bound to a surface of a carbonaceous material. The porous carbon coating later contains porous carbon particles, and thus shows reduced resistance during lithium-ion intercalation on the surface of the carbonaceous material and provides improved surface reactivity and structural stability. This provides improved high-rate charge characteristics, while causing no deterioration of charge/discharge efficiency and life characteristics, when being used as a negative electrode active material for a lithium secondary battery. The self-bound amorphous carbon coating layer may optionally have a controlled pore structure through chemical etching.

First claim

1 . A negative electrode active material for a lithium secondary battery, comprising:
a carbonaceous material; and a porous carbon coating layer self-bound to a surface of the carbonaceous material.

2 . The negative electrode active material for the lithium secondary battery according to claim 1 , wherein the porous carbon coating layer comprises at least one metal element selected from Zn, Co, Cu, Ti, Hf, Zr, Ni, Mg, Ti, V, Cr, Fe or Al.

3 . The negative electrode active material for the lithium secondary battery according to claim 1 , wherein the porous carbon coating layer comprises at least one metal element of Zn or Co.

4 . The negative electrode active material for the lithium secondary battery according to claim 1 , wherein a content of the porous carbon coating layer is 50 wt % or less based on a total weight of the negative electrode active material.

5 . The negative electrode active material for the lithium secondary battery according to claim 1 , wherein the carbonaceous material has a number average particle diameter of 25 μm or less.

6 . A lithium secondary battery comprising a negative electrode comprising the negative electrode active material for the lithium secondary battery as defined in claim 1 .

7 . A method for preparing a negative electrode active material for a lithium secondary battery, comprising the steps of:
preparing a carbonaceous material; and growing a metal-organic framework (MOF) directly on Uthefla surface of the carbonaceous material; drying the carbonaceous material on which having the MOF grown on the surface: and heat treating the dried carbonaceous material on which having the MOF grown on the surface to form a porous carbon coating layer containing comprising a metal element on the surface of the carbonaceous material.

8 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 7 , wherein the step of growing a metal organic framework (MOF) the MOF directly on the surface of the carbonaceous material comprises:
(a) a step of mixing preparing a precursor solution containing comprising a metal compound, an organic compound and hydrogen peroxide and mixing the precursor solution with the carbonaceous material to grow the metal organic framework MOF directly on the surface of the carbonaceous material; or (b) a step of mixing a carbonaceous material composition comprising the carbonaceous material dispersed in hydrogen peroxide with a metal compound solution and an organic compound solution to grow a metal organic framework the MOF directly on the surface of the carbonaceous material, wherein the metal compound solution comprises the metal compound, and the organic compound solution comprises the organic compound.

9 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein the metal compound comprises at least one of a metal acetate, a metal nitrate, a metal carbonate, ora metal hydroxide, or two or more of them.

10 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein the metal compound comprises at least one metal element of Zn, Co, Cu, Ti, Hf, Zr, Ni, Mg, Ti, V, Cr, Fe, or Al.

11 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein the metal compound comprises at least one metal element of Zn or Co.

12 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein the organic compound comprises at least one of a carboxylic acid compound or an imidazole compound.

13 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein the metal compound is at least one of Zn acetate or Co acetate, and the organic compound is 2-methyl imidazole.

14 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 8 , wherein hydrogen peroxide is used in an amount of 1 wt % to 50 wt % in the precursor solution to induce direct growth of the MOF on the surface of the carbonaceous material.

15 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 7 , wherein the drying step is carried out at 25° C. to 120° C.

16 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 7 , wherein the heat treatment step is carried out under inert gas atmosphere at 800° C. to 1,500° C. for 1 hour to 10 hours.

17 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 7 , which further comprises a chemical etching step for removing the metal element, after the step of forming a porous carbon coating layer.

18 . The method for preparing the negative electrode active material for the lithium secondary battery according to claim 17 , wherein the chemical etching step is carried out by agitating the negative electrode active material in an acid solution at a concentration of 0.5M to 3 M for 1 hour to 10 hours, followed by drying at 25° C. to 120° C.

Assignees

• Lg Energy Solution Ltd
• Univ Industry Cooperation Group Kyung Hee Univ

Inventors

• Woo Sang-Wook
• Kim Je-Young
• Lee Yong-Ju
• Kim Jun-Young
• Park Min-Sik

Classifications

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/366 Primary

  as layered products · CPC title