Electrode active material, method for producing same, electrode for nonaqueous secondary battery, and nonaqueous secondary battery

Patent metadata

Field	Value
Publication number	US-9911968-B2
Application number	US-201013062488-A
Country	US
Kind code	B2
Filing date	Mar 10, 2010
Priority date	Apr 10, 2009
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

An electrode active material includes particles of a lithium-containing composite oxide represented by the general compositional formula: Li 1+x MO 2 , where −0.15≦x≦0.15, and M represents an element group of three or more elements including at least Ni, Co and Mn, wherein the ratios of Ni, Co and Mn to the total elements constituting M satisfy 45≦a≦90, 5≦b≦30, 5≦c≦30 and 10≦b+c≦55, where the ratios of Ni, Co and Mn are represented by a, b and c, respectively, in units of mol %, the average valence A of Ni in the whole particles is 2.2 to 3.2, the valence B of Ni on the surface of the particles has the relationship: B<A, the average valence C of Co in the whole particles is 2.5 to 3.2, the valence D of Co on the surface of the particles has the relationship: D<C, and the average valence of Mn in the whole particles is 3.5 to 4.2.

First claim

The invention claimed is:

1. An electrode active material comprising particles of a lithium-containing composite oxide represented by the general compositional formula:
Li 1+x MO 2 ,
where x is within a range of −0.05≦x≦0.15, and M represents an element group of three or more elements including at least Ni, Co and Mn,
wherein the ratios of Ni, Co and Mn to the total elements constituting M satisfy 45≦a≦60, 5≦b≦30, 5≦c≦30 and 10≦b+c≦55, where the ratios of Ni, Co and Mn are represented by a, b and c, respectively, in units of mol%,
the average valence A of Ni in the whole particles is 2.2 to 3.2, the valence B of Ni on the surface of the particles has the relationship: B<A,
the average valence C of Co in the whole particles is 2.5 to 3.2, the valence D of Co on the surface of the particles has the relationship: D≦C, and
the average valence of Mn in the whole particles is 3.5 to 4.2.

2. The electrode active material according to claim 1 ,
wherein the average valence A of Ni in the whole particles is 2.2 to 2.9, and the valence B of Ni on the surface of the particles has the relationship: B≦A.

3. The electrode active material according to claim 1 ,
wherein the ratio b of Co and the ratio c of Mn have the relationship: b>c.

4. The electrode active material according to claim 1 ,
wherein the ratio b of Co and the ratio c of Mn have the relationship: b≦c.

5. The electrode active material according to claim 1 ,
wherein the lithium-containing composite oxide is represented by the general compositional formula: Li 1+x Ni 1 −d−e CO d Mn e O 2 , where −0.15≦x≦0.15, 0.05≦d≦0.3, 0.05≦e≦0.3, and 0.1≦d+e≦0.55.

6. The electrode active material according to claim 1 ,
wherein the lithium-containing composite oxide is formed by washing a composite oxide of Li and the element group M with water or an organic solvent, heat treating the washed composite oxide at a temperature of 600 to 1000° C. in an atmosphere containing 18 vol% or more of oxygen, and pulverizing the composite oxide.

7. The electrode active material according to claim 1 ,
wherein the particles of the lithium-containing composite oxide have a true density of 4.55 to 4.95 g/cm 3 .

8. The electrode active material according to claim 1 ,
wherein in the particles of the lithium-containing composite oxide, the ratio of primary particles having a particle size of 1 μm or less to the total primary particles of the lithium-containing composite oxide particles is 30 vol% or less.

9. The electrode active material according to claim 1 ,
wherein the lithium-containing composite oxide has a BET specific surface area of 0.1 to 0.3 m 2 /g.

10. The electrode active material according to claim 1 ,
wherein the particles of the lithium-containing composite oxide has a spherical shape.

11. An electrode for a non-aqueous secondary battery comprising an electrode material mixture layer containing the electrode active material according to claim 1 , wherein the electrode material mixture layer has a density of 3.2 to 3.8 g/cm 3 .

12. The electrode for a non-aqueous secondary battery according to claim 11 ,
wherein the electrode material mixture layer has a density of 3.5 to 3.8 g/cm 3 .

13. A non-aqueous secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolyte,
wherein the positive electrode is the electrode for a non-aqueous secondary battery according to claim 11 .

14. The electrode active material according to claim 1 ,
wherein the valence D of Co on the surface of the particles is 2.65 or less.

Assignees

• Kono Satoshi
• Kishimi Mitsuhiro
• Hatakeyama Atsushi
• Maxell Holdings Ltd

Inventors

• Kono Satoshi
• Kishimi Mitsuhiro
• Hatakeyama Atsushi

Classifications

• C01P2006/11

  Powder tap density · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• C01P2004/32

  Spheres · CPC title