Lithium-manganese-based composite oxide containing titanium and nickel

• US 7,713,662 B2
• Filed: 11/13/2007
• Issued: 05/11/2010
• Est. Priority Date: 11/20/2006
• Status: Expired due to Fees

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Oka, Yuko, Takeuchi, Tomonari, Tatsumi, Kuniaki, Tabuchi, Mitsuharu
• Primary Examiner(s): Pyon; Harold Y
• Assistant Examiner(s): CHIANG, TIMOTHY S
• Application Number:
  US11/979,961
• Publication Number:
  US 20080116418A1
• Time in Patent Office: 910 Days
• Field of Search: 429/231.95, 429/223, 429/224, 429/231.5, 423/49, 423/69, 423/76, 423/138, 423/179.5, 252/182.1
• US Class Current: 429/231.95
• CPC Class Codes: C01G 23/003 Titanates C01G23/001 takes precedence
• CPC Class Codes: C01G 45/1228 of the type [MnO2]n- , e.g. LiMnO2, Li[MxMn1-x]O2
• CPC Class Codes: C01G 53/50 of the type [MnO2]n- , e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/76 by a space-group or by other symmetry indications
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: C01P 2002/78 by stacking-plane distances or stacking sequences
• CPC Class Codes: C01P 2004/01 depicted by an image
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• 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

Abstract

The invention provides a lithium-manganese-based composite oxide containing Ti and Ni, which is represented by the compositional formula: Li_1+x(Mn_1−n−mNi_mTi_n)_1−xO₂, wherein 0<x≦0.33, 0.05<m<0.3, and 0.3<n<0.5, and includes a crystal phase of layered rock-salt type structure. The composite oxide is a novel material that is capable of maintaining an average discharge voltage of 3 V or more over long charge/discharge cycles, while providing a discharge capacity equal to or higher than those of lithium-cobalt-oxide-based positive electrode materials, and that can be prepared using starting materials that are inexpensive and less limited as natural resources, while exhibiting improved charge/discharge characteristics over known low-cost positive electrode materials.

Claims

1. A lithium-manganese-based composite oxide having a crystal phase of layered rock-salt structure and a crystal phase of cubic rock-salt structure, containing Ti and Ni, and represented by the compositional formula:

Li_1+x(Mn<sub>1−

n−

m</sub>Ni_mTi_n)<sub>1−

x</sub>O₂, wherein

0<

x≦

0.33,

0.05<

m<

0.3, and

0.3<

n<

0.5.

2. The lithium-manganese-based composite oxide containing Ti and Ni according to claim 1, wherein the molar ratio of Ni to Mn is from 0.2 to 0.7.

3. A method for preparing a lithium-manganese-based composite oxide containing Ti and Ni as defined in claim 1, comprising

forming a precipitate by alkalizing an aqueous solution containing a manganese compound, a titanium compound, and a nickel compound;

hydrothermally treating the precipitate along with an oxidizing agent and a water-soluble lithium compound under alkaline conditions; and

firing the hydrothermally treated product in the presence of a lithium compound.

4. A positive electrode material for lithium-ion batteries, comprising a lithium-manganese-based composite oxide containing Ti and Ni as defined in claim 1.

5. A lithium-ion battery comprising a positive electrode material as defined in claim 4.