Stoichiometrically Controlled Lithium Cobalt Oxide Based Compounds

Patent metadata

Field	Value
Publication number	US-2016006032-A1
Application number	US-201514855456-A
Country	US
Kind code	A1
Filing date	Sep 16, 2015
Priority date	Jun 17, 2011
Publication date	Jan 7, 2016
Grant date	—

Abstract

A lithium metal oxide powder for use as a cathode material in a rechargeable battery, consisting of a core material and a surface layer, the core having a layered crystal structure consisting of the elements Li, a metal M and oxygen, wherein the Li content is stoichiometrically controlled, wherein the metal M has the formula M═Co 1-a M′ a , with O≦a≦0.05, wherein M′ is either one or more metals of the group consisting of Al, Ga and B; and the surface layer consisting of a mixture of the elements of the core material and inorganic N-based oxides, wherein N is either one or more metals of the group consisting of Mg, Ti, Fe, Cu, Ca, Ba, Y, Sn, Sb, Na, Zn, Zr and Si.

First claim

1 . A lithium metal oxide powder for a cathode material in a rechargeable battery, comprising a core material and a surface layer, the core having a layered crystal structure consisting of the elements Li, a metal M and oxygen, wherein the metal M has the formula M═Co i-a M′ a , wherein M′ is Al or M′ is Al and either one or more of Mg, Ti, Ga and B; and the surface layer comprising Li, Co, and inorganic N-based oxides or lithiated oxides, wherein N is Al, Ti and Mg or N is Al, Ti, Mg and either one or more metals of the group consisting of Fe, Cu, Ca, Ba, Y, Sn, Sb, Na, Zn, Zr and Si, and wherein the molar ratios Mg:Co>0.004, Al:Co>0.004 and wherein the sum of Mg, Al and Ti molar contents in the core is less than the sum of Mg, Al and Ti molar contents in the surface layer.

2 . The lithium metal oxide powder of claim 1 , wherein the molar ratio Li:(Co+Al) is more than 0.98 and less than 1.01.

3 . The lithium metal oxide powder of claim 1 , having a mean particle size D50 of at least 15 μm.

4 . The lithium metal based powder of claim 1 , wherein the powder has a bimodal particle shape distribution where the small particle size fraction has a D50≦5 μm and is between 3 to 20 Vol %, and where the large particle size fraction has a D50≧15 μm.

5 . The lithium metal oxide powder of claim 1 , wherein the density of a relaxed pellet of the powder is greater than 3.80 g/cm 3 after applying a pressure of 207MPa.

6 . The lithium metal oxide powder of claim 1 , wherein the thickness of the surface layer is 1 μm or less.

7 . The lithium metal oxide powder of claim 1 , wherein the Al content in the core is radially constant, and less than the Al content in the surface layer.

8 . The lithium metal oxide powder of claim 1 , wherein the Al:Co molar ratio in the surface layer is more than 2a/(1-a).

9 . The lithium metal oxide powder of claim 1 , wherein either one or more of the Mg:Co and Ti:Co molar ratios in the surface layer is more than 2 times the corresponding Mg:Co or Ti:Co molar ratios in the powder.

10 . The lithium metal oxide powder of claim 1 , wherein either one or more of the Mg:Co and Ti:Co molar ratio in the surface layer is more than 5 times the corresponding Mg:Co or Ti:Co molar ratios in the powder.

11 . The lithium metal oxide powder of claim 1 , having an electrical conductivity less than 10 −5 S/cm as measured under a pressure of 63.7 MPa at 25° C.

12 . The lithium metal oxide powder of claim 1 , wherein the molar ratios Mg:Co>0.009 and Al:Co>0.009.

13 . The lithium metal oxide powder of claim 1 , wherein the onset time of gas generation in a sealed 1600 mAh state-of-the-art pouch cell having as positive active material said lithium metal based powder is at least 70 hrs, the cell being stored at 50° C. and subjected to a float-current voltage of 4.40 V.

14 . The lithium metal oxide powder of claim 1 , consisting acomprising monolithic, potato-shaped and non-agglomerated particles.

15 . The lithium metal oxide powder of claim 1 , wherein the BET is lower than 0.3 m 2 /g.

16 . The lithium metal oxide powder of claim 1 , having a capacity versus voltage differential ratio dQ/dV<700 mAh/gN in the 4.40V to 4.70V voltage range vs. Li metal during a first charge at C/10 rate.

17 . The lithium metal oxide powder of claim 1 , having a capacity versus voltage differential ratio dQ/dV<2000 mAh/gN in the 4.51V to 4.70V voltage range vs. Li metal during a first discharge at C/10 rate.

18 . The lithium metal oxide powder of claim 1 , having a Carbon content less than 50 ppm.

19 . The lithium metal oxide powder of claim 1 , having a SBC content less than 25 μmol/g.

20 . A cathode in an electrochemical cell comprising the lithium metal oxide powder according to claim 1 .

Assignees

• Umicore Nv

Inventors

• Paulsen Jens
• Blangero Maxime
• Choi Da-In

Classifications

• C01D15/02

  Oxides; Hydroxides · CPC title

• C01P2006/40

  Electric properties · CPC title

• H01M4/131

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

• C01G51/00 Primary

  Compounds of cobalt · CPC title

• H01M4/366

  as layered products · CPC title