Electric device

Patent metadata

Field	Value
Publication number	US-10276866-B2
Application number	US-201415537270-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Dec 17, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

In an electric device the negative electrode active material layer includes a silicide phase containing a silicide of a transition metal is dispersed in a parent phase containing amorphous or low crystalline silicon as a main component, a predetermined composition, and a ratio value (B/A) of a diffraction peak intensity B of a silicide of a transition metal in a range of 2θ=37 to 45° to a diffraction peak intensity A of a ( 111 ) plane of Si in a range of 2θ=24 to 33° in a predetermined range in an X-ray diffraction measurement using a CuKα1 ray is used as a Si-containing alloy. A solid solution or an oxide-coated solid solution in which a coating layer containing an oxide in a predetermined amount is formed on the particle surface of the solid solution and is used in the positive electrode active material layer.

First claim

The invention claimed is:

1. An electric device which comprises a power generating element including:
a positive electrode in which a positive electrode active material layer containing a positive electrode active material is formed on the surface of a positive electrode current collector;
a negative electrode in which a negative electrode active material layer containing a negative electrode active material is formed on the surface of a negative electrode current collector; and
a separator, wherein
the negative electrode active material layer contains a negative electrode active material represented by the following Formula (1):
α(Si-containing alloy)  (1)

wherein α represents a percent by weight of each component in the negative electrode active material layer and 40<α≤98,
the positive electrode active material layer contains a positive electrode active material represented by the following Formula (2):
e (Solid-solution positive electrode active material)  (2)

wherein e represents a percent by weight of each component in the positive electrode active material layer and 80≤e≤98, and
wherein the Si-containing alloy has a structure including a silicide phase which contains a silicide of a transition metal and is dispersed in a parent phase containing amorphous silicon as a main component and a composition represented by the following Chemical Formula (I):
Si x Sn y M z A a   (I)

wherein A is unavoidable impurities, M is Ti, x, y, z, and a represent values of percent by mass, and 0<x<100, 0<y<100, 0<z<100, and 0≤a<0.5 and x+y+z+a=100,
a ratio value (B/A) of a diffraction peak intensity B of a silicide of a transition metal in a range of 2θ=37 to 45° to a diffraction peak intensity A of a ( 111 ) plane of Si in a range of 2θ=24 to 33° is 0.41 or more in an X-ray diffraction measurement of the Si-containing alloy using a CuKαl ray, and
the solid-solution positive electrode active material contains an oxide-coated solid solution including a coating layer which contains an oxide or composite oxide of a metal selected from the group consisting of Al, Zr, and Ti and is formed on a particle surface of a solid solution having a composition represented by the following Formula (3):
Li 1.5 [Ni a Mn b Co c [Li] d ]O z   (3)

wherein z represents the number of oxygen satisfying the valence, a+b+c+d=1.5, 0.1≤d≤0.4, and 1.1≤[a+b+c]≤1.4, and wherein a content of the oxide or composite oxide in the solid-solution positive electrode active material is from 0.1 to 3.0% by weight in terms of oxide.

2. The electric device according to claim 1 , wherein B/A is 0.89 or more.

3. The electric device according to claim 2 , wherein B/A is 2.55 or more.

4. The electric device according to claim 3 , wherein B/A is 7.07 or more.

5. The electric device according to claim 1 , wherein the diffraction peak intensity A (cps) of the ( 111 ) plane of Si is from 6000 to 25000 and the diffraction peak intensity B (cps) of a silicide of a transition metal is from 9000 to 46000.

6. The electric device according to claim 1 , wherein the diffraction peak intensity A (cps) of the ( 111 ) plane of Si is from 6000 to 15000 and the diffraction peak intensity B (cps) of a silicide of a transition metal is from 25000 to 46000.

7. The electric device according to claim 1 , wherein the parent phase is more amorphized than the silicide phase.

8. The electric device according to claim 1 , wherein a size of the silicide phase is 50 nm or less.

9. The electric device according to claim 1 , wherein 7<z <100 in Chemical Formula (I) above.

10. The electric device according to claim 1 , wherein a thickness of the coating layer is from 2 to 20 nm.

11. The electric device according to claim 1 , which is a lithium ion secondary battery.

Assignees

• Nissan Motor

Inventors

• Watanabe Manabu
• Kaburagi Tomohiro
• Yoshioka Youichi
• Komatsu Hirokazu
• Chiba Nobutaka
• Yamamoto Shinji

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505

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

• H01M4/485

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