Positive electrode active material for lithium secondary battery, method for preparing same, and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-2020106095-A1
Application number	US-201716468874-A
Country	US
Kind code	A1
Filing date	Dec 7, 2017
Priority date	Dec 12, 2016
Publication date	Apr 2, 2020
Grant date	—

Abstract

A positive electrode active material for a lithium secondary battery according to an embodiment of the present invention includes a lithium transition metal composite oxide and doping metals doped in the lithium-transition metal composite oxide, wherein the doping metals includes at least two kinds and the average oxidation number of the doping metals is greater than 3.5.

First claim

1 . A positive electrode active material for a lithium secondary battery, comprising
a lithium transition metal composite oxide and doping metals doped in the lithium-transition metal composite oxide, wherein the doping metals comprises at least two kinds and the average oxidation number of the doping metals is greater than 3.5.

2 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the average oxidation number of the doping metals is in the range of 3.5 to 5.

3 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the doping metals comprise
at least one selected from the group comprising aluminum (Al), boron (B), gallium (Ga), indium (In), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), thallium (Tl), and a combination thereof, and, and at least one selected from the group comprising molybdenum (Mo), chromium (Cr), and tungsten (W).

4 . The positive electrode active material for a lithium secondary battery of claim 3 , wherein the positive electrode active material for a lithium secondary battery is represented by Chemical Formula 1 and the doping metals are represented by M 1 and M 2 in Chemical Formula 1:
Li a (Ni x Co y Mn 1-x-y ) b (M 1 zM 2 1-z ) c O 2   [Chemical Formula 1]
wherein, in Chemical Formula 1, 0.95≤a≤1.1, 0<b<1, 0<c<0.02, 0.5≤x<1, 0≤y≤0.2,and 0.5≤z<1.

5 . The positive electrode active material for a lithium secondary battery of claim 4 , wherein the z is greater than or equal to 0.6.

6 . The positive electrode active material for a lithium secondary battery of claim 4 , wherein the xis greater than or equal to 0.8.

7 . The positive electrode active material for a lithium secondary battery of claim 4 , wherein the c is greater than or equal to about 0.015.

8 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the positive electrode active material for a secondary battery has an a-axis lattice parameter of 2.865 Å to 2.874 Å.

9 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the positive electrode active material for a secondary battery has a c-axis lattice parameter of 14.180 Å to 14.214 Å.

10 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the positive electrode active material for a secondary battery has c-axis lattice parameter/a-axis lattice parameter of 4.945 to 4.950.

11 . A method of preparing the positive electrode active material for a lithium secondary battery, comprising
1) mixing a mixture of a transition metal precursor and a lithium precursor with a doping metal precursor having an average oxidation number of greater than +3.5; and 2) firing the mixture obtained in the step 1) to form the positive electrode active material, wherein the positive electrode active material is represented by Chemical Formula 1, and the doping metal is represented by M 1 and M 2 in Chemical Formula 1:
Li a (Ni x Co y Mn 1-x-y ) b (M 1 z M 2 1-z ) c O 2   [Chemical Formula 1]

wherein, in Chemical Formula 1, 0.95≤a≤1.1, 0<b<1, 0<c<0.02, 0.5≤x<1, and 0≤y≤0.2, 0.5≤z<1.

12 . The method of preparing the positive electrode active material for a lithium secondary battery of claim 11 , wherein M l is at least one selected from the group consisting of aluminum (Al), boron (B), gallium (Ga), indium (In), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), and thallium (Tl), and
M 2 is at least one selected from the group consisting of molybdenum (Mo), chromium (Cr) and tungsten (W).

13 . The method of preparing the positive electrode active material for a lithium secondary battery of claim 11 , wherein the x is greater than or equal to 0.8, the z is greater than or equal to 0.6, and the c is less than or equal to 0.015.

14 . The method of preparing the positive electrode active material for a lithium secondary battery of claim 11 , wherein the firing is performed for 20 hours to 30 hours including temperature increasing and decreasing time within a temperature range of 400° C. to 900° C.

15 . A lithium secondary battery comprising
a positive electrode for a lithium secondary battery comprising the positive electrode active material of claim 1 ; a negative electrode overlapped therewith; and a separator interposed between the positive electrode and the negative electrode, and an electrolyte.

Assignees

• Posco
• Res Inst Ind Science & Tech

Inventors

• Nam Sang Cheol
• Lee Jae Won
• Park Jong Il
• Lee Jae Myung
• Park Geun Gyung

Classifications

• H01M4/131

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

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• H01M4/485 Primary

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title

• C01P2006/40

  Electric properties · CPC title