Positive-electrode materials: methods for their preparation and use in lithium secondary batteries

Patent metadata

Field	Value
Publication number	US-9577253-B2
Application number	US-201214349076-A
Country	US
Kind code	B2
Filing date	Oct 4, 2012
Priority date	Oct 4, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A positive-electrode material for a lithium secondary battery which includes a lithium oxide compound or a complex oxide as reactive substance. The material also includes at least one type of carbon material, and optionally a binder. A first type of carbon material is provided as a coating on the reactive substance particles surface. A second type of carbon material is carbon black. And a third type of carbon material is a fibrous carbon material a mixture of at least two types of fibrous carbon material different in fiber diameter and/or fiber length. Also, a method for preparing the material as well as lithium secondary batteries including the material.

First claim

The invention claimed is:

1. A positive-electrode material for a lithium secondary battery, comprising a lithium oxide compound as reactive substance, carbon material, and optionally a binder, wherein the carbon material comprises:
a first carbon material, the first carbon material being a coating on the reactive substance;
a second carbon material, the second carbon material being carbon black; and
a third carbon material, the third carbon material being a fibrous carbon material comprising a mixture of at least two fibrous carbon materials, wherein one of the fibrous carbon materials has fiber diameters of about 5 to 15 nm and the other of the fibrous carbon materials has fiber diameters of about 70 to 150 nm.

2. A positive-electrode material according to claim 1 , wherein the lithium oxide compound comprises a metal which is a transition metal.

3. A positive-electrode material according to claim 1 , wherein the lithium oxide compound is a phosphate, an oxyphosphate, a silicate, an oxysilicate, or a fluorophosphate.

4. A positive-electrode material according to claim 1 , wherein the lithium oxide is LiFePO 4 , LiMnPO 4 , LiFeSiO 4 , SiO, SiO 2 or SiO x wherein 0≦x<2.

5. A positive-electrode material according to claim 1 , wherein the first carbon material is in graphene or amorphous form, and bonds are formed between carbon atoms, thereby facilitating electron conductivity.

6. A positive-electrode material according to claim 1 , wherein a thickness of the coating of the first carbon material is about 1 to 10 nm.

7. A positive-electrode material according to claim 1 , wherein the carbon black is conductive carbon black.

8. A positive-electrode material according to claim 1 , wherein the at least two fibrous carbon materials are carbon nanotubes, carbon nanofibers or a combination thereof; and wherein the at least two fibrous carbon materials are different in fiber length.

9. A positive-electrode material according to claim 1 , wherein the fibrous carbon materials having fiber diameters of about 5 to 15 nm have fiber lengths of about 1 to 3 μm, and the fibrous carbon materials having fiber diameters of about 70 to 150 nm have fiber lengths of about 5 to 10 μm.

10. A positive-electrode material according to claim 1 , wherein a combined amount of the second and third carbon materials is not less than about 2 wt % for a total amount of the carbon material.

11. A positive-electrode material according to claim 1 , wherein a weight ratio of the second and third carbon materials is about (2 to 8)/(1 to 3).

12. A positive-electrode material according to claim 1 , wherein the binder is a fluorine-containing resin, a thermoplastic resin, a dispersion resin, or a combination thereof.

13. A lithium secondary battery comprising the electrode-positive material as defined in claim 1 .

14. A positive-electrode material for a lithium secondary battery, comprising a complex oxide compound as reactive substance, carbon material, and optionally a binder, wherein the carbon material comprises:
a first carbon material, the first carbon material being a coating on the reactive substance;
a second carbon material, the second carbon material being carbon black; and
a third carbon material, the third carbon material being a fibrous carbon material comprising a mixture of at least two fibrous carbon materials, wherein one of the fibrous carbon materials has fiber diameters of about 5 to 15 nm and the other of the fibrous carbon materials has fiber diameters of about 70 to 150 nm,
wherein the complex oxide compound is a complex oxide of general formula A a M m Z z O o N n F f ,

wherein:
A represents an alkaline metal;
M represents a transition metal, and optionally at least one non-transition metal, or a mixture thereof;
Z represents a non-metallic element;
N is a nitrogen atom;
F is a fluorine atom; and
a≧0, m≧0, z≧0, o>0, n≧0 and f≧0, a, m, o, n, f and z being selected to ensure electro neutrality of the complex oxide.

Assignees

• Hydro Quebec
• Sei Corp

Inventors

• Zaghib Karim
• Guerfi Abdelbast
• Hovington Pierre
• Sawai Takehiko
• Saito Shinji
• Urao Kazunori

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• 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