Positive active material, method of preparing the same, and lithium battery including the positive active material

Patent metadata

Field	Value
Publication number	US-9444098-B2
Application number	US-201313849839-A
Country	US
Kind code	B2
Filing date	Mar 25, 2013
Priority date	Oct 15, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A positive active material including: a lithium-containing oxide, and a lithium-intercalatable phosphate compound disposed on the lithium-containing oxide.

First claim

What is claimed is:

1. A positive active material comprising:
a lithium-containing oxide; and
a lithium-intercalatable phosphate compound disposed on the lithium-containing oxide,
wherein the phosphate compound includes both primary particles and secondary particles including the primary particles,
wherein the primary particles of the phosphate compound have an average particle diameter of from about 0.01 nanometers to about 1,000 nanometers,
wherein the secondary particles of the phosphate compound have an average particle diameter of from about 0.02 nanometers to about 15 micrometers,
wherein at least some of the phosphate compound is in a form of a coating on at least a portion of a surface of a particle of the lithium-containing oxide, and the phosphate compound is further disposed inside a particle of the lithium-containing oxide,
wherein the phosphate compound is a compound represented by Formula 1:
MOPO 4   Formula 1

wherein, in Formula 1,
M is at least one selected from a transition metal having an ionic diameter of from about 60 angstroms to about 90 angstroms and an oxidation number of +5, and
wherein the lithium-containing oxide comprises at least one compound selected from compounds represented by Formulas 2 to 4:
x Li[Li 1/3 Me 2/3 ]O 2 -(1 −x )LiMe′O 2   Formula 2

wherein, in Formula 2,
0< x< 0.9;
Me is at least one element selected from manganese, molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, and platinum; and
Me′ is at least one element selected from nickel, manganese, and cobalt;
y Li[Li 1/3 ((M1) a (M2) b (Mn) c ) 2/3 ]O 2 -(1 −y )LiMe′O 2   Formula 3

wherein in Formula 3,
0 ≦a≦ ⅓;

0 ≦b≦ ⅓;

a+b+c= 1;
0 <y< 0.9; and
M1 is at least one element selected from nickel, copper, zinc, cobalt, chromium, iron, and magnesium; and
M2 is at least one element selected from molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, and platinum;
Li d Co 1-e-g Ni e (M3) g O 2-j (X1) j   Formula 4

wherein, in Formula 4,
0.8 <d≦ 1.6;
0 ≦e≦ 1;
0 ≦g≦ 0.5;
0 ≦j≦ 1;
M3 is at least one element selected from nickel, cobalt, copper, magnesium, sodium, calcium, titanium, zinc, gallium, germanium, aluminum, chromium, magnesium, strontium, molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, silver, gold, hafnium, tin, and platinum; and
X1 is at least one element selected from oxygen, fluorine, sulfur, and phosphorus.

2. The positive active material of claim 1 , wherein the phosphate compound comprises at least one selected from MoOPO 4 , TiOPO 4 , VOPO 4 , TaOPO 4 , and NbOPO 4 .

3. The positive active material of claim 1 , wherein the phosphate compound has a layered structure or a tunneled structure.

4. The positive active material of claim 1 , wherein the phosphate compound has a single crystalline structure.

5. The positive active material of claim 1 , wherein the phosphate compound has a crystalline structure of at least one selected from an α I phase, α II phase, β phase, γ phase, δ phase, ε phase, and a ω phase.

6. The positive active material of claim 1 , wherein an amount of the phosphate compound is from about 0.001 parts to about 30 parts by weight, based on 100 parts by weight of the lithium-containing oxide.

7. The positive active material of claim 1 , wherein the coating has a thickness of from about 0.01 nanometers to about 9.99 micrometers.

8. The positive active material of claim 1 , wherein an amount of the phosphate compound is from about 0.001 parts to about 10 parts by weight, based on 100 parts by weight of the lithium-containing oxide.

9. The positive active material of claim 1 , wherein an amount of the phosphate compound is from about 0.001 parts to about 5 parts by weight, based on 100 parts by weight of the lithium-containing oxide.

10. A lithium battery comprising: a positive electrode; an electrolyte; and a negative electrode, wherein the positive electrode comprises the positive active material of claim 1 .

11. The lithium battery of claim 10 , wherein an operating voltage of the positive active material is in the range of 4.3 Volts±0.1 Volts versus lithium or greater.

12. A method of preparing a positive active material, the method comprising:
heating a transition metal precursor to prepare a lithium-intercalatable phosphate compound; and
contacting the phosphate compound with a lithium-containing oxide to prepare the positive active material, which comprises a mixture of the lithium-containing oxide and the phosphate compound, wherein:
the phosphate compound includes both primary particles and secondary particles, the secondary particles including the primary particles,
the primary particles of the phosphate compound have an average particle diameter of from about 0.01 nanometers to about 1,000 nanometers,
the secondary particles of the phosphate compound have an average particle diameter of from about 0.02 nanometers to about 15 micrometers,
at least some of the phosphate compound is in a form of a coating on at least a portion of a surface of a particle of the lithium-containing oxide, and the phosphate compound is further disposed inside a particle of the lithium-containing oxide,
the phosphate compound is a compound represented by Formula 1:
MOPO 4   Formula 1

wherein, in Formula 1,
M is at least one selected from a transition metal having an ionic diameter of from about 60 angstroms to about 90 angstroms and an oxidation number of +5, and
the lithium-containing oxide comprises at least one compound selected from compounds represented by Formulas 2 to 4:
x Li[Li 1/3 Me 2/3 ]O 2 -(1 −x )LiMe′O 2   Formula 2

wherein, in Formula 2,
0< x< 0.9;
Me is at least one element selected from manganese, molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, and platinum; and
Me′ is at least one element selected from nickel, manganese, and cobalt;
y Li[Li 1/3 ((M1) a (M2) b (Mn) c ) 2/3 ]O 2 -(1 −y )LiMe′O 2   Formula 3

wherein, in Formula 3,
0 ≦a≦ ⅓;

0 ≦b≦ ⅓;

a+b+c= 1;
0 <y< 0.9; and
M1 is at least one element selected from nickel, copper, zinc, cobalt, chromium, iron, and magnesium; and
M2 is at least one element selected from molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, and platinum;
Li d Co 1-e-g Ni e (M3) g O 2-j (X1) j   Formula 4

wherein, in Formula 4,
0.8 <d≦ 1.6;
0 ≦e≦ 1;
0 ≦g≦ 0.5;
0 ≦j≦ 1;
M3 is at least one element selected from nickel, cobalt, copper, magnesium, sodium, calcium, titanium, zinc, gallium, germanium, aluminum, chromium, magnesium, strontium, molybdenum, tungsten, vanadium, titanium, zirconium, ruthenium, rhodium, palladium, osmium, iridium, silver, gold, hafnium, tin, and platinum; and
X1 is at least one element selected from oxygen, fluorine, sulfur, and phosphorus.

13. The method of claim 12 , wherein the transition metal precursor is at least one selected from MoOPO 4 .2H 2 O, TiOPO 4 .2H 2 O, VOPO 4 .2H 2 O, VOHPO 4 .0.5H 2 O, VPO 4 .H 2 O, TaOPO 4 .3.4H 2 O, TaOPO 4 .2.1H 2 O, TaOPO 4 .2.3H 2 O, TaOPO 4 .1.3H 2 O, and NbOPO 4 .H 2 O.

14. The method of claim 12 , wherein the heating is performed at a temperature from about 500° C. to about 1,200° C. for about 12 hours to about 48 hours.

15. The method of claim 12 , wherein an amount of the phosphate compound is from about 0.001 parts to about 30 parts by weight, based on 100 parts by weight of

Assignees

• Samsung Sdi Co Ltd
• Samsung Corning Prec Mat Co Ltd
• Samsung Fine Chemicals Co Ltd

Inventors

• Park Jun-Ho
• Mun Jun-Young
• Park Jin-Hwan
• Yoon Jae-Gu

Classifications

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/131 Primary

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