Cathode additive for lithium secondary battery, preparation method therefor, cathode for lithium secondary battery, comprising same, and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-2022181627-A1
Application number	US-201917298778-A
Country	US
Kind code	A1
Filing date	Nov 12, 2019
Priority date	Nov 30, 2018
Publication date	Jun 9, 2022
Grant date	—

Abstract

The present invention relates to a positive electrode additive for a lithium secondary battery, a manufacturing method thereof, a positive electrode for a lithium secondary battery including the same, and a lithium secondary battery including the same.The positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention is represented by Chemical Formula 1 below.Li6xCo1-yMyO4  [Chemical Formula 1](In the Chemical Formula 1, 0.9≤x≤1.1, 0<y≤0.1, My=BaWb, 0≤a≤0.1, 0≤b≤0.1, and, a and b are not simultaneously 0.)Another positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention includes a core represented by Chemical Formula 2 below; and a coating layer comprising at least one of boron (B) and tungsten (W).Li6xCoO4  [Chemical Formula 2](In the Chemical Formula 2, 0.9≤x≤1.1.)

First claim

What is claimed is:

1 . A positive electrode additive for lithium secondary battery represented by Chemical Formula 1 below.
Li 6x Co 1-y M y O 4   [Chemical Formula 1]
(In the Chemical Formula 1, 0.9≤x≤1.1, 0<y≤0.1, My=B a W b , 0≤a≤0.1, 0≤b≤0.1, and a and b are not simultaneously 0.)

2 . The positive electrode additive of claim 1 , wherein:
the positive electrode additive is coated with one or more of boron (B) and tungsten (W).

3 . A positive electrode additive for lithium secondary battery, comprising:
a core represented by Chemical Formula 2 below; and a coating layer comprising at least one of boron (B) and tungsten (W).
Li 6x CoO 4   [Chemical Formula 2]

(In the Chemical Formula 2, 0.9≤x≤1.1.)

4 . A method of manufacturing a positive electrode additive for lithium secondary battery, comprising:
preparing a metal hydroxide precursor particle of CoO or Co (OH) 2 ; preparing a mixture by mixing the precursor particle, lithium raw material, and doping raw material; prepare a calcined product by calcining the mixture; and cooling and pulverizing the calcined material; wherein, the doping raw material comprises at least one of boron (B) and tungsten (W).

5 . The method of claim 4 , wherein:
the lithium raw material is at least one selected from the group consisting of Li 2 CO 3 , LiOH, C 2 H 3 LiO 2 , LiNO 3 , Li 2 SO 4 , Li 2 SO 3 , Li 2 O, Li 2 O 2 , and LiCl.

6 . The method of claim 4 , wherein:
wherein, a mixing ratio of the precursor particle and the lithium raw material is 1:5.9 to 1:6.1 by molar ratio.

7 . The method of claim 4 , wherein:
a mixing ratio of the doping raw material to the mixture is 0.001 to 0.02 by molar ratio.

8 . The method of claim 4 , wherein:
in the step of preparing a calcined product by calcining the mixture, the calcination condition is in an inert atmosphere for 1 to 15 hours at a temperature range of 600 to 800° C.

9 . A method of manufacturing a positive electrode additive for lithium secondary battery, comprising:
preparing a compound represented by the following Chemical Formula 3; preparing a mixture by mixing the compound and doping raw material; preparing a calcined product by calcining the mixture; and cooling and pulverizing the calcined material; wherein, the doping raw material comprises at least one of boron (B) and tungsten (W).
Li 6x CO a B b W c O 4   [Chemical Formula 3]

(In the Chemical Formula 3, 0.9≤x≤1.1, 0.9≤a≤1, 0≤b≤0.1, 0≤c≤0.1)

10 . The method of claim 9 , wherein:
a mixing ratio of the doping raw material to the compound represented by the Chemical Formula 3 is 0.001 to 0.02 by molar ratio.

11 . The method of claim 9 , wherein:
in the step of calcining the mixture to prepare a calcined product; a calcining condition is in an inert atmosphere for 1 to 10 hours in a temperature range of 250 to 450° C.

12 . The method of claim 4 or claim 9 , wherein:
after obtaining a lithium metal oxide, the method further comprises forming a coating layer by mixing the coating raw material with the lithium metal oxide and calcining that; and the coating raw material comprises at least one of boron (B) and tungsten (W).

13 . A positive electrode for lithium secondary battery, comprising:
a current collector; and a positive active material layer positioned on the current collector surface; wherein, the positive electrode active material layer comprises a positive electrode active material and a positive electrode additive, the positive electrode additive is represented by the following Chemical Formula 3, and with respect to the sum of 100 wt % of the positive electrode active material and positive electrode additive, the positive electrode additive is 0.1 to 7 wt %.
Li 6x CO a B b W c O 4   [Chemical Formula 3]

(In the Chemical Formula 3, 0.9≤x≤1.1, 0.9≤x≤1.1, 0.9≤a≤1, 0≤b≤0.1, 0.1, and 0≤c≤0.1)

14 . The positive electrode of claim 13 , wherein:
the positive electrode additive is coated with at least one of boron (B) and tungsten (W).

15 . The positive electrode of claim 13 , wherein:
the positive electrode additive is decomposed during initial charging and discharging and converted into a Li supply source and a compound represented by Chemical Formula 4 below.
LiCo 1-y M y O 2   [Chemical Formula 4]

(In the Chemical Formula 4, 0<y≤0.1, My=B a W b , 0≤a≤0.1, and 0≤b≤0.1)

16 . A lithium secondary battery, comprising:
a positive electrode; a negative electrode; and an electrolyte positioned between the positive and negative electrodes, the positive electrode comprises the positive electrode additive according to claim 1 or claim 3 .

Assignees

• Posco
• Res Inst Ind Science & Tech

Inventors

• Park Jong Il
• Lee Jae Myung
• Hwangbo Geun
• Nam Sang Cheol

Classifications

• C01G51/82

  Compounds containing cobalt, with or without oxygen or hydrogen, and containing two or more other elements · 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

• C01G51/42 Primary

  containing alkali metals, e.g. LiCoO2 · CPC title

• C01P2006/40

  Electric properties · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title