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-2019181444-A1
Application number	US-201916280421-A
Country	US
Kind code	A1
Filing date	Feb 20, 2019
Priority date	Nov 13, 2015
Publication date	Jun 13, 2019
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,
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.

2 . The method for producing the positive-electrode material for the lithium ion secondary battery according to claim 1 , wherein the boroxine compound is triisopropoxyboroxin ((BO) 3 (O(CH)(CH 3 ) 2 ) 3 ).

3 . The method for producing the positive-electrode material for the lithium ion secondary battery according to claim 1 , wherein the fluoride is lithium hexafluorophosphate (LiPF 6 ).

4 . 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.

5 . The method for producing a positive-electrode material for a lithium ion secondary battery according to claim 4 , wherein the organic titanium compound is a titanium-containing chelating agent.

6 . 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.

Assignees

• Hitachi Metals Ltd

Inventors

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

Classifications

• C01G51/50

  of the type (MnO2)n-, e.g. Li(CoxMn1-x)O2 or Li(MyCoxMn1-x-y)O2 · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/366

  as layered products · CPC title

• C01P2004/02

  obtained by optical microscopy · CPC title

• C01P2006/40

  Electric properties · CPC title