Positive-electrode material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2017358799-A1
Application number	US-201615540730-A
Country	US
Kind code	A1
Filing date	Nov 9, 2016
Priority date	Nov 13, 2015
Publication date	Dec 14, 2017
Grant date	—

Abstract

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li 1+a Ni b Mn c Co d Ti e M f O 2+α , and has an atomic ratio Ti 3+ /Ti 4+ between Ti 3+ and Ti 4+ , as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1, and −0.2≦α≦0.2.

First claim

1 . A positive-electrode material for a lithium ion secondary battery, the positive-electrode material containing a lithium complex compound represented by the following Formula (1) and having an atomic ratio Ti 3+ /Ti 4+ between Ti 3+ and Ti 4+ , as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20:
Li 1+a Ni b Mn c Co d Ti e M f O 2+α   (1),

where in the Formula (1), M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1, and −0.2≦α≦0.2.

2 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein a concentrated Ti 3+ layer is provided on a surface of a secondary particle formed from a plurality of agglomerated primary particles of the lithium complex compound.

3 . The positive-electrode material for a lithium ion secondary battery according to claim 1 having a particle fracture strength greater than or equal to 50 MPa and less than or equal to 200 MPa.

4 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein a BET specific surface area is greater than or equal to 0.2 m 2 /g and less than or equal to 2.0 m 2 /g.

5 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein a/e≦5 is satisfied in the Formula (1).

6 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein e in the Formula (1) satisfies 0.005≦e≦0.15.

7 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein a in the Formula (1) satisfies 0≦a≦0.06.

8 . The positive-electrode material for a lithium ion secondary battery according to claim 1 , wherein
a plurality of primary particles of the lithium complex compound agglomerate to form a secondary particle, and a surface of the secondary particle is fluorinated.

9 . A method for producing the positive-electrode material for a lithium ion secondary battery according to claim 1 , comprising applying surface treatment to the positive-electrode material for the lithium ion secondary battery by immersing the positive-electrode material in an organic solvent containing dissolved therein a boroxine compound represented by the following Formula (2) and fluoride:
(BO) 3 (OR) 3   (2),
where R in the Formula (2) is an organic group having one or more carbon atoms.

10 . The method for producing the positive-electrode material for a lithium ion secondary battery according to claim 9 , wherein the boroxine compound is triisopropoxyboroxin ((BO) 3 (O(CH)(CH 3 ) 2 ) 3 ).

11 . The method for producing the positive-electrode material for a lithium ion secondary battery according to claim 9 , wherein the fluoride is lithium hexafluorophosphate (LiPF 6 ).

12 . A method for producing a positive-electrode material for a lithium ion secondary battery, comprising:
a mixing step of mixing a lithium-containing compound with compounds each containing a metal element other than Li in the following Formula (1), thereby obtaining a mixture; and firing the mixture under an oxidizing atmosphere to obtain a lithium complex compound, the lithium complex compound being represented by the following Formula (1) and having an atomic ratio Ti 3+ /Ti 4+ between Ti 3+ and Ti 4+ , as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20, wherein the compounds each containing a metal other than Li in the mixing step comprise an organic titanium compound as a Ti-containing compound:
Li 1+a Ni b Mn c Co d Ti e M f O 2+α   (1),

where in the Formula (1), M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1, and −0.2≦α≦0.2.

13 . The method for producing a positive-electrode material for a lithium ion secondary battery according to claim 12 , wherein the organic titanium compound is a titanium-containing chelating agent.

14 . A method for producing a positive-electrode material for a lithium ion secondary battery, comprising:
a mixing step of mixing a lithium-containing compound with compounds each containing a metal element other than Li in the following Formula (1), thereby obtaining a mixture; and firing the mixture under an oxidizing atmosphere to obtain a lithium complex compound, the lithium complex compound being represented by the following Formula (1) and having an atomic ratio Ti 3+ /Ti 4+ between Ti 3+ and Ti 4+ , as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20, wherein the compounds each containing a metal other than Li in the mixing step comprise titanium oxide as a Ti-containing compound:
Li 1+a Ni b Mn c Co d Ti e M f O 2+α   (1),

where in the Formula (1), M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1,and −0.2≦α≦0.2.

15 . (canceled)

16 . A positive-electrode material for a lithium ion secondary battery, the positive-electrode material containing a lithium complex compound represented by the following Formula (1) and having a concentrated Ti 3+ layer on a surface of a secondary particle formed from a plurality of agglomerated primary particles of the lithium complex compound:
Li 1+a Ni b Mn c Co d Ti e M f O 2+α   (1),

where in the Formula (1), M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1, and −0.2≦α≦0.2.

17 . The positive-electrode material for the lithium ion secondary battery according to claim 1 having a particle fracture strength greater than or equal to 50 MPa and less than or equal to 200 MPa and having a BET specific surface area greater than or equal to 0.2 m 2 /g and less than or equal to 2.0 m 2 /g, wherein e in the Formula (1) satisfies 0.005≦e≦0.15 and a in the Formula (1) satisfies 0≦a≦0.06.

18 . A lithium ion secondary battery comprising the positive-electrode material for a lithium ion secondary battery according to claim 1 .

Assignees

• Hitachi Metals Ltd

Inventors

• Gunji Akira
• Tokoro Hisato
• Takahashi Shin
• Toyama Tatsuya
• Haruna Hiroshi
• TAKAMATSU Daiko
• Nakabayashi Takashi
• Takano Shuichi

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/505 Primary

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

• C01P2002/50

  Solid solutions · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title