Method of Preparing Positive Electrode Active Material

Patent metadata

Field	Value
Publication number	US-2021028445-A1
Application number	US-201916982812-A
Country	US
Kind code	A1
Filing date	Mar 20, 2019
Priority date	Apr 12, 2018
Publication date	Jan 28, 2021
Grant date	—

Abstract

A method of preparing a positive electrode active material that includes introducing a reaction mixture including a lithium source material and a nickel-manganese-cobalt precursor into a continuous firing furnace and subjecting the same to primary heat treatment, thereby preparing a fired mixture; subjecting the fired mixture to pulverization or size classification; and introducing the fired mixture having been pulverized or size-classified into a rotary kiln and subjecting the same to secondary heat treatment, thereby forming a lithium nickel manganese cobalt-based positive electrode active material.

First claim

1 . A method of preparing a positive electrode active material comprising:
introducing a reaction mixture including a lithium source material and a nickel-manganese-cobalt precursor into a continuous firing furnace and performing primary heat treatment, thereby preparing a fired mixture; subjecting the fired mixture to pulverization or size classification; and introducing the fired mixture having been pulverized or size-classified into a rotary kiln and performing secondary heat treatment, thereby forming a lithium nickel manganese cobalt-based positive electrode active material.

2 . The method of claim 1 , wherein the continuous firing furnace is a roller hearth kiln.

3 . The method of claim 1 , wherein the rotary kiln includes a rotary cylindrical tube having an inlet portion and an outlet portion, wherein the rotary cylindrical tube is disposed such that it is inclined at an angle of 2° to 8° and the outlet portion is not level with the inlet portion.

4 . The method of claim 3 , wherein the rotary cylindrical tube is rotated at a rate of 0.5 rpm to 8 rpm during the secondary heat treatment.

5 . The method of claim 3 , wherein the rotary cylindrical tube has the length-to-diameter ratio of 2 to 20.

6 . The method of claim 1 , wherein the primary heat treatment is performed in a temperature range of 300° C. to 900° C.

7 . The method of claim 1 , wherein the primary heat treatment is performed under an oxygen atmosphere or an air atmosphere.

8 . The method of claim 1 , wherein the secondary heat treatment is performed in a temperature range of 600° C. to 1,000° C.

9 . The method of claim 1 , wherein the secondary heat treatment is performed under an atmosphere in which oxygen partial pressure is no more than 20%.

10 . The method of claim 1 , wherein the secondary heat treatment is performed under a nitrogen atmosphere or a vacuum atmosphere.

11 . The method of claim 1 , wherein the primary heat treatment is performed for 3 hours to 15 hours.

12 . The method of claim 1 , wherein the secondary heat treatment is performed for 1 hour to 7 hours.

13 . The method of claim 1 , wherein the lithium nickel manganese cobalt-based positive electrode active material is represented by the following Chemical Formula 1:
Li 1+x [Ni a Mn b Co c M 1 1−a−b−c ] 1−x O 2   [Chemical Formula 1]

wherein, in Chemical Formula 1, −0.2≤x≤0.2, 0<a<1, 0<b<1, 0<c<1, and M 1 is one or more selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo.

Assignees

• Lg Chemical Ltd

Inventors

• Jung Won Sig
• Cho Seung Beom
• Choi Sang Soon

Classifications

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C01P2006/40

  Electric properties · CPC title

• B01J19/28

  Moving reactors, e.g. rotary drums (B01J19/08 takes precedence) · CPC title