Positive electrode active material for lithium secondary batteries, positive electrode for lithium secondary batteries, and lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2016380263-A1
Application number	US-201515113679-A
Country	US
Kind code	A1
Filing date	Jan 26, 2015
Priority date	Jan 27, 2014
Publication date	Dec 29, 2016
Grant date	—

Abstract

A positive electrode active material for a lithium secondary battery, comprising a lithium-containing composite metal oxide in the form of secondary particles formed by aggregation of primary particles capable of being doped and undoped with lithium ions, each of the secondary particles having on its surface a coating layer, the positive electrode active material satisfying the following requirements (1) to (3):
(1) the metal oxide has an α-NaFeO 2 type crystal structure of following formula (A):
Li a (Ni b Co c M 1 1-b-c )O 2   (A)

wherein 0.9≦a≦1.2, 0.9≦b<1, 0<c≦0.1, 0.9<b+c≦1, and M 1 represents at least one optional metal selected from Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn;
(2) the coating layer comprises Li and M 2 , wherein M 2 represents at least one optional metal selected from Al, Ti, Zr and W; and
(3) the active material has an average secondary particle diameter of 2 to 20 μm, a BET specific surface area of 0.1 to 2.5 m 2 /g, and a value of 1.0 to 2.0 as a tamped density/untamped density ratio of the active material.

First claim

1 . A positive electrode active material for a lithium secondary battery, comprising a lithium-containing composite metal oxide in the form of secondary particles formed by aggregation of primary particles capable of being doped and undoped with lithium ions, each of the secondary particles having on its surface a coating layer, the positive electrode active material satisfying the following requirements (1) to (3):
(1) the lithium-containing composite metal oxide has an α-NaFeO 2 type crystal structure represented by the following formula (A):
Li a (Ni b Co c M 1 1-b-c )O 2   (A)

wherein 0.9≦a≦1.2, 0.9≦b<1, 0<c≦0.1, 0.9<b+c≦1, and M 1 represents at least one optional metal selected from the group consisting of Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn;
(2) the coating layer comprises Li and M 2 , wherein M 2 represents at least one optional metal selected from the group consisting of Al, Ti, Zr and W; and
(3) the positive electrode active material has an average secondary particle diameter of 2 μm to 20 μm, a BET specific surface area of 0.1 m 2 /g to 2.5 m 2 /g, and a value of 1.0 to 2.0 as obtained by dividing a tamped density of the positive electrode active material by the untamped density of the positive electrode active material.

2 . The positive electrode active material according to claim 1 , wherein M 1 is at least one metal selected from the group consisting of Mg, Al, Ca, Ti, Mn, Zn, Ga, Zr and Sn.

3 . The positive electrode active material according to claim 1 , wherein M 1 is at least one metal selected from the group consisting of Mg, Al, Mn, Zn and Sn.

4 . The positive electrode active material according to claim 1 , which has a tamped density of 1.0 g/cm 3 to 3.5 g/cm 3 .

5 . The positive electrode active material according to claim 1 , wherein a value of [90% cumulative diameter (D 90 )/10% cumulative diameter (D 10 )] as obtained from the particle size distribution measurement values is 1 to 5.

6 . The positive electrode active material according to claim 1 , wherein an atomic ratio of M 2 is 0.1 to 5 mol %, relative to the sum of atomic ratios of Ni, Co and M 1 .

7 . The positive electrode active material according to claim 1 , wherein M 2 is Al.

8 . The positive electrode active material according to claim 1 , wherein the coating layer is formed of lithium aluminate.

9 . A positive electrode for a lithium secondary battery, comprising the positive electrode active material of claim 1 .

10 . A lithium secondary battery, comprising the positive electrode of claim 9 .

Assignees

• Sumitomo Chemical Co
• Tanaka Chemical Corp

Inventors

• Nakayama Tetsuri
• Takamori Kenji
• Doumae Kyousuke
• Kitamoto Takashi

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title