Method for manufacturing positive electrode active material for lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2024300825-A1
Application number	US-202218280663-A
Country	US
Kind code	A1
Filing date	Feb 22, 2022
Priority date	Mar 26, 2021
Publication date	Sep 12, 2024
Grant date	—

Abstract

A method for manufacturing a positive electrode active material for a lithium ion secondary battery involves reacting at least 95 mass % of a lithium compound through a heat treatment step using a rotary firing furnace and having a batch firing process for heating a precursor while rolling the same in a heating region in a furnace tube, wherein the batch firing process has: a tilted input stage for tilting the furnace tube and inputting the precursor from an inlet of the firing furnace; a horizontal firing stage for performing firing while making the furnace tube horizontal; and a tilted discharge stage for tilting the furnace tube and discharging a fired powder from an outlet of the firing furnace.

First claim

1 . A method for manufacturing a positive electrode active material for a lithium ion secondary battery, the method comprising:
a mixing step of mixing a lithium compound and a compound containing a metal element other than Li in the following formula (1) to obtain a powder mixture; a first heat treatment step of thermally treating the powder mixture to obtain a precursor; a second heat treatment step of thermally treating the precursor to obtain a fired powder; and a third heat treatment step of thermally treating the fired powder to obtain a lithium complex compound represented by the following formula (1), wherein 95 mass % or more of the lithium compound is reacted in the second heat treatment step having a batch firing process for heating the precursor while rolling the same in a heating region in a furnace tube, and the batch firing process has a tilted input stage for tilting the furnace tube and inputting the precursor from an inlet of the firing furnace, a horizontal firing stage for performing firing while making the furnace tube horizontal, and a tilted discharge stage for tilting the furnace tube and discharging the fired powder from an outlet of the firing furnace,
Li 1+a Ma1O 2+α   (1)

here, in the formula (1), M1 is the metal element other than Li and includes at least Ni, a proportion of the Ni in M1 is 70 atom % or more and a and α are numbers satisfying −0.1≤a≤0.2 and −0.2≤α≤0.2.

2 . The method for manufacturing a positive electrode active material for a lithium ion secondary battery according to claim 1 ,
wherein the furnace tube includes a supply-side spiral blade from the inlet to the heating region and a discharge-side spiral blade from the heating region to the outlet, and, in the batch firing process, the precursor is collected in the heating region.

3 . The method for manufacturing a positive electrode active material for a lithium ion secondary battery according to claim 1 ,
wherein the furnace tube includes a supply-side spiral blade from the inlet to an inlet of the heating region, includes a lifter in the heating region and, additionally, includes a discharge-side spiral blade from an outlet of the heating region to the outlet, and a height of the lifter is lower than heights of the supply-side spiral blade and/or the discharge-side spiral blade, thereby firing the precursor present in the heating region while circulating the same.

4 . The method for manufacturing a positive electrode active material for a lithium ion secondary battery according to claim 3 ,
wherein the lifter in the heating region is a spiral blade.

5 . The method for manufacturing a positive electrode active material for a lithium ion secondary battery according to claim 1 ,
wherein rotation speeds of the furnace tube in the tilted input stage and/or the tilted discharge stage are set to be higher than a rotation speed of the furnace tube in the horizontal firing stage.

6 . The method for manufacturing a positive electrode active material for a lithium ion secondary battery according to claim 1 ,
wherein the formula (1) is represented by the following formula (2), an average particle diameter of a slurry in the mixing step is set to 0.1 μm or more and 0.5 μm or less, an average particle diameter of secondary particles in a granulated powder obtained by granulating the slurry is set to 5 μm or more and 20 μm or less, the first heat treatment step thermally treats the granulated powder at a heat treatment temperature of 200° C. or higher and 500° C. or lower for 0.5 hours or longer and five hours or shorter to obtain a precursor, the second heat treatment step thermally treats the precursor at a heat treatment temperature of 600° C. or higher and lower than 750° C. for 10 hours or longer and 100 hours or shorter in an oxidizing atmosphere to obtain a fired powder, and the third heat treatment step thermally treats the fired powder at a heat treatment temperature of 750° C. or higher and 900° C. or lower for 0.5 hours or longer and 50 hours or shorter in an oxidizing atmosphere to obtain a lithium complex compound,
Li 1+a Ni b Co c M d X e O 2+α   (2)

here, in the formula (2), M represents at least one selected from Al and Mn, X represents at least one metal element other than Li, Ni, Co, Al and Mn, and a, b, c, d, e and α are numbers satisfying −0.1≤a≤0.2, 0.7≤b≤1.0, 0≤c≤0.20, 0≤d≤0.20, 0≤e≤0.20, b+c+d+e=1, and −0.2<α<0.2, respectively.

Assignees

• Proterial Ltd

Inventors

• Takano Shuichi
• Tokoro Hisato
• Gunji Akira
• Takahashi Shin

Classifications

• H01M10/0525

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

• C01P2006/40

  Electric properties · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title