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

Patent metadata

Field	Value
Publication number	US-10090525-B2
Application number	US-201715405662-A
Country	US
Kind code	B2
Filing date	Jan 13, 2017
Priority date	Oct 4, 2011
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A positive-electrode material for a lithium secondary battery. The material 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 provided as 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 method of preparing a positive-electrode material for a lithium secondary battery, comprising:
(a) providing a complex oxide compound as reactive substance;
(b) coating a surface of particles of the reactive substance with a carbon material; and
(c) mixing the coated reactive substance with (i) carbon black, (ii) a mixture of at least a first fibrous carbon material and a second fibrous carbon material, the second fibrous carbon material being different in fiber diameter and/or fiber length from the first fibrous carbon material, and (iii) optionally a binder,
wherein step (c) is performed by compression shear impact particle-compositing technique,
wherein the complex oxide compound is a complex oxide of general formula A a M m Z z O o N n F f , and 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,

wherein the first fibrous carbon material has a fiber diameter of about 5 to 15 nm and the second fibrous carbon material has a fiber diameter of about 70 to 150 nm,
wherein the first fibrous carbon material has a fiber length of about 1 to 3 μm and the second fibrous carbon material has a fiber length of about 5 to 10 μm.

2. A method according to claim 1 , further comprising (d) calcining a a mixture obtained in step (c).

3. A method according to claim 1 , wherein step (d) is performed at a temperature of about 700 to 850° C.

4. A method according to claim 1 , wherein step (d) is performed during a period of time of about 0.5 to 2 hours.

5. A method according to claim 1 , wherein step (d) is performed under inert atmosphere.

6. A method according to claim 1 , wherein:
A is Li;
M is Fe, Mn, V, Ti, Mo, Nb, W, Zn or a mixture thereof; and
Z is P, S, Se, As, Si, Ge, B or a mixture thereof.

Assignees

• Hydro Quebec
• Sei Corp

Inventors

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

Classifications

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• H01M4/0428

  Chemical vapour deposition · CPC title

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/0471 Primary

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title