Cathode active material for secondary battery and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2016028076-A1
Application number	US-201414420427-A
Country	US
Kind code	A1
Filing date	Sep 30, 2014
Priority date	Sep 30, 2013
Publication date	Jan 28, 2016
Grant date	—

Abstract

Provided are a method of manufacturing a cathode active material including a first step of preparing a metal glycolate solution, a second step of mixing lithium-containing transition metal oxide particles and the metal glycolate solution and stirring in a paste state, a third step of drying the paste-state mixture, and a fourth step of performing a heat treatment on the dried mixture, a cathode active material including a metal oxide layer which is manufactured by the above method, and a secondary battery composed of a cathode including the cathode active material.

First claim

1 . A method of manufacturing a cathode active material, the method comprising steps of:
a first step of preparing a metal glycolate solution; a second step of mixing lithium-containing transition metal oxide particles and the metal glycolate solution and stirring in a paste state; a third step of drying the paste-state mixture; and a fourth step of performing a heat treatment on the dried mixture.

2 . The method of claim 1 , wherein the first step of preparing a metal glycolate solution comprises:
preparing a mixed solution by dispersing a metal precursor and a chelating agent in a glycol-based solvent; performing primary heating on the mixed solution; and performing secondary heating on the mixed solution.

3 . The method of claim 2 , wherein the glycol-based solvent comprises a single material selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol, or a mixture of two or more thereof.

4 . The method of claim 2 , wherein the metal precursor comprises a single material selected form the group consisting of acetate, hydroxide, nitrate, nitride, sulfate, sulfide, alkoxide, and halide, which include at least one metal selected form the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), yttrium (Y), titanium (Ti), zirconium (Zr), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), iron (Fe), cobalt (Co), iridium (Ir), nickel (Ni), zinc (Zn), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), lanthanum (La), and cerium (Ce), or a mixture of two or more thereof.

5 . The method of claim 2 , wherein the chelating agent comprises a single material selected from the group consisting of citric acid, ethylenediaminetetraacetic acid (EDTA), oxalic acid, and gluconic acid, or a mixture of two or more thereof.

6 . The method of claim 2 , wherein a content ratio (parts by weight) of the metal precursor: the glycol-based solvent: the chelating agent is in a range of 1:1:0.1 to 1:500:20.

7 . The method of claim 2 , wherein the primary heating is performed in a temperature range of 150° C. to 300° C. for 1 hour to 48 hours.

8 . The method of claim 2 , wherein the secondary heating is performed in a temperature range of 150° C. to 300° C. for 1 hour to 5 hours.

9 . The method of claim 2 , wherein the primary heating and the secondary heating are performed in an inert gas atmosphere including argon (Ar).

10 . The method of claim 1 , wherein the metal glycolate solution comprises a single material selected from the group consisting of aluminum glycolate, zirconium glycolate, titanium glycolate, calcium glycolate, and manganese glycolate, or a mixture of two or more thereof.

11 . The method of claim 1 , wherein the lithium-containing transition metal oxide is selected from the group consisting of LiMO 2 (M=Co, Mn, Ni, Ni 1/3 Co 1/3 Mn 1/3 , Cr, or V) , LiMO 4 (M=CoMn, NiV, CoV, CoP, FeP, MnP, NiP, or Mn 2 ), Li(Ni a Co b Mn c )O 2 (0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiNi 1-y Co y O 2 , LiCo 1-y Mn y O 2 , LiNi 1-y Mn y O 2 (O≦y≦1), Li(Ni a Mn b Co c )O 4 (0<a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn 2-z Ni z O 4 , LiMn 2-z Co z O 4 (O<z<2), and LiV 3 O 6 .

12 . The method of claim 11 , wherein the lithium-containing transition metal oxide is LiCoO 2 , LiNiO 2 , LiMnO 2 , LiCuO 2 , LiMn 2 O 4 , LiNi 1/3 Mn 1/3 O 2 , LiNi 0.6 Mn 0.2 O 2 , LiCoPO 4 , or LiFePO 4 .

13 . The method of claim 1 , wherein the drying is performed in a temperature range of 100° C. to 200° C. for 1 hour to 4 hours.

14 . The method of claim 1 , wherein the heat treatment is performed in a temperature range of 200° C. to 1,200° C. for 1 hour to 3 hours.

15 . A cathode active material manufactured by the method of claim 1 , the cathode active material comprising:
lithium-containing transition metal oxide particles; and a metal oxide layer coated on surfaces of the lithium-containing transition metal oxide particles.

16 . The cathode active material of claim 15 , wherein the metal oxide layer comprises at least one compound selected from the group consisting of metal organo-compounds represented by Chemical Formulae 1 to 3:
M(C 2 H 5 O 2 ) n   [Chemical Formula 1]
M(C 6 H (8-n) O 7 )  [Chemical Formula 2]
M(C 6 H (8-n) O 7 )(C 2 H 5 O 2 )  [Formula 3]
(where M, as a metal desorbed from a metal precursor, represents at least one metal selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), yttrium (Y), titanium (Ti), zirconium (Zr), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), iron (Fe), cobalt (Co), iridium (Ir), nickel (Ni), zinc (Zn), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), lanthanum (La), and cerium (Ce), and n is an integer between 1 and 4).

17 . The cathode active material of claim 15 , wherein a thickness of the metal oxide layer is in a range of 5 nm to 500 nm.

18 . The cathode active material of claim 15 , wherein an amount of metal in the metal oxide layer is in a range of 0.01 wt % to 10 wt % based on a total amount of the lithium-containing transition metal oxide.

19 . A cathode for a secondary battery comprising:
a cathode collector; and the cathode active material of claim 15 coated on the cathode collector.

20 . A lithium secondary battery comprising:
the cathode of claim 19 ; an anode; a separator disposed between the cathode and the anode; and a lithium salt-containing non-aqueous electrolyte solution.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Dong Kwon
• Cho Seung Beom
• Nho Jun Seok
• Jang Wook

Classifications

• C01G45/1242

  of the type (Mn2O4)-, e.g. LiMn2O4 or Li(MxMn2-x)O4 · CPC title

• C01G31/006

  Compounds containing vanadium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01G51/52

  of the type (Mn2O4)2-, e.g. Li2(CoxMn2-x)O4 or Li2(MyCoxMn2-x-y)O4 · CPC title

• H01M4/131

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

• C01G53/50

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title