LITHIUM COMPOSITE COMPOUND PARTICLES AND PROCESS FOR PRODUCING THE SAME, AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

• US 20110281168A1
• Filed: 12/03/2009
• Published: 11/17/2011
• Est. Priority Date: 12/04/2008
• Status: Active Grant

• Current Assignee: TODA Kogyo Corporation
• Original Assignee: TODA Kogyo Corporation
• Inventors: Watanabe, Hiroyasu, Tagami, Nobuyuki, Kikuya, Kazuhiko, Imahashi, Taiki, Sadamura, Hideaki
• Granted Patent: US 9,455,444 B2
• Time in Patent Office: Days
• US Class Current: 429/223
• CPC Class Codes: C01G 53/42 containing alkali metals, e.g. LiNiO2
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0566 Liquid materials
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to lithium composite compound particles having a composition represented by the formula: Li_1+xNi_1-y-zCo_yM_zO₂ (M=B or Al), wherein the lithium composite compound particles have an ionic strength ratio A (LiO⁻/NiO₂⁻) of not more than 0.3 and an ionic strength ratio B (Li₃CO₃⁺/Ni⁺) of not more than 20 as measured on a surface of the respective lithium composite compound particles using a time-of-flight secondary ion mass spectrometer. The lithium composite compound particles of the present invention can be used as a positive electrode active substance of a secondary battery which has good cycle characteristics and an excellent high-temperature storage property.

Claims

1. Lithium composite compound particles comprising a lithium composite compound represented by the following compositional formula 1, which lithium composite compound particles have an ionic strength ratio A (LiO⁻

/NiO₂⁻

) of not more than 0.3 and an ionic strength ratio B (Li₃CO₃⁺/Ni⁺) of not more than 20 as measured on a surface of the respective lithium composite compound particles using a time-of-flight secondary ion mass spectrometer;

Li_1+xNi_1-y-zCo_yM_zO₂ 

 

Compositional formula 1

wherein M is at least one element selected from the group consisting of B and Al; and

x, y and z satisfy −

0.02≦

x≦

0.02, 0<

y≦

0.20 and 0<

z≦

0.10, respectively.

2. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have an average secondary particle diameter of 1 to 30 μ

m.

3. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have a powder pH value of not more than 11.0 as measured in a 2% by weight suspension prepared by dispersing the lithium composite compound particles in water.

4. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have a carbon content of not more than 300 ppm.

5. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have a sulfur content of not more than 100 ppm, an ionic strength ratio C (LiSO₃⁻

/NiO₂⁻

) of not more than 0.3 and a sodium content of not more than 100 ppm.

6. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have a lithium carbonate component content of not more than 0.30% by weight and a lithium hydroxide content of not more than 0.30% by weight.

7. Lithium composite compound particles according to claim 1, wherein the lithium composite compound particles have a specific surface area of 0.05 to 0.7 m²/g.

10. A non-aqueous electrolyte secondary battery comprising the lithium composite compound particles as defined in claim 1.

8. A process for producing the lithium composite compound particles as defined in a, comprising the steps of (1) treating lithium composite compound particles with a water solvent to remove impurities therefrom;

and (2) subjecting the lithium composite compound particles obtained in the step (1) to heat treatment,

a ratio of a total molar amount of lithium to a total molar amount of a transition element, aluminum and boron in the lithium composite compound particles used in the step (1) being not less than 1.02 and not more than 1.10.

9. A process according to claim 8, wherein the heat treatment in the step (2) is conducted in a temperature range of 500 to 850°

C. in an air or oxygen atmosphere having a carbonate concentration of not more than 100 ppm.