Positive Electrode Active Material for Lithium Battery

• US 20120012776A1
• Filed: 03/31/2010
• Published: 01/19/2012
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Mitsui Mining and Smelting Company Limited
• Original Assignee: Mitsui Mining and Smelting Company Limited
• Inventors: Kagei, Shinya, Miyanohara, Keisuke, Hata, Yoshimi, Ochi, Yasuhiro, Sasaki, Kenji
• Granted Patent: US 8,703,341 B2
• Time in Patent Office: Days
• US Class Current: 252/62.51R
• CPC Class Codes: C01G 45/1242 of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• 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 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/51 Particles with a specific particle size distribution
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2006/11 Powder tap density
• 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 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• 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 4/40 Alloys based on alkali metals
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• 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: Y02E 60/10 : Energy storage using batteries

Abstract

With the object of providing a positive electrode active material for lithium battery that can increase the filling density, can increase the output characteristics, and furthermore, with a small voltage decrease during conservation at high temperature in a charged state, a positive electrode active material for lithium battery is proposed, containing a spinel type (Fd3-m) lithium transition metal oxide represented by general formula Li_1+xM_2-xO_4-δ (where M represents a transition metal including Mn, Al and Mg, x represents 0.01 to 0.08 and 0≦δ) and a boron compound, the inter-the atomic distance Li—O of the spinel type lithium transition metal oxide being 1.971 Å to 2.006 Å, and the amount of magnetic substance measured for the positive electrode active material for lithium battery being 600 ppb or less.

Claims

1. A positive electrode active material for lithium battery, containing a spinel type Fd3-m lithium transition metal oxide represented by general formula Li_1+xM_2-xO_4-δ

wherein M consists of Mn, Al and Mg. x represents 0.01 to 0.08 and 0≦

δ

, and a boron compound,

the spinel type Fd3-m lithium transition metal oxide having an inter-atomic distance Li—

O of 1.978 Å

to 2.006 Å

as measured by the Rietveld method using the fundamental method, and the amount of magnetic deposit measured for the positive electrode active material for lithium battery by the measurement method described below being 600 ppb or less.

(Method for measuring the amount of magnetic deposit)

Using a 500 cc lidded resinous container, 500 cc of ion-exchanged water and one cylindrical stirring bar-type magnet covered with tetrafluoroethylene (a magnet which range of magnetic force falls within 100 mT to 150 mT when the magnetic force is measured using TESLA METER Model TM-601 by KANETEC) are added to 100 g of positive electrode active substance material (powder), which is placed on a ball mill rotating stage, and rotating to produce a slurry. Next, the magnet is taken out, immersed in ion-exchanged water and the excess powder attached to the magnet is eliminated with an ultrasound cleaner. Next the magnet is taken out, immersed in aqua regia, heated at 80°

C. for 30 minutes in aqua regia to dissolve magnetic deposits, aqua regia in which magnetic deposit has dissolved is analyzed for the amounts of iron, nickel, chromium and zinc with ICP Atomic Emission Spectrometer, and, with the total amounts thereof as the amount of magnetic deposit, the amount of magnetic deposit per weight of positive electrode active substance material is calculated.

2. The positive electrode active material for lithium battery according to the claim 1, wherein the spinel type lithium transition metal oxide is represented by the general formula Li(Li_xMg_yAl_zMn_2-x-y-z)O_4-δ

wherein 0.01≦

x≦

0.08, 0.02≦

y≦

0.07, 0.06≦

z≦

0.14 and 0≦

δ

.

3. The positive electrode active material for lithium battery according to the claim 1, wherein the crystallite size of the spinel type lithium transition metal oxide is 500 nm to 2000 nm.

4. The positive electrode active material for lithium battery according to claim 2, wherein the crystallite size of the spinel type lithium transition metal oxide is 500 nm to 2000 nm.

5. A lithium battery for an electric vehicle or for a hybrid electric vehicle provided with the positive electrode active material for lithium battery according to claim 1 as a positive electrode active substance.