Electrode and secondary battery

Patent metadata

Field	Value
Publication number	US-11469408-B2
Application number	US-201716337620-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Sep 29, 2016
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

Disclosed is an electrode, comprising: a metal foil; an electrode layer formed on at least one surface of the metal foil; and an insulating layer formed on the electrode layer; wherein boundary portion between the insulating layer and the electrode layer is in a state in which a part of the insulating layer engages into a part of the electrode layer, and Ls/L is 1.25 or more, wherein a reference length of a straight line in a direction in which the metal foil extends is taken as L and a boundary length along boundary between the insulating layer and the electrode layer is taken as Ls.

First claim

The invention claimed is:

1. An electrode, comprising:
a metal foil;
an electrode layer formed on at least one surface of the metal foil; and
an insulating layer formed on the electrode layer;
wherein the electrode layer includes a lithium nickel composite oxide which is a positive electrode active material and is obtained by partially replacing Ni of nickel lithate (LiNiO 2 ) with another metal element, and polyvinylidene fluoride (PVdF) which is a binder,
wherein the insulating layer includes alumina particles, and polyvinylidene fluoride (PVdF) which is a binder,
wherein a boundary portion between the insulating layer and the electrode layer is in a state in which a part of the insulating layer engages into a part of the electrode layer,
Ls/Lis 1.25 or more

wherein a reference length of a straight line in a direction in which the metal foil extends is taken as L and a boundary length along the boundary between the insulating layer and the electrode layer is taken as Ls,
RSm is from 24 to 40 μm

wherein an average length of elements at the boundary between the insulating layer and the electrode layer is taken as RSm, and
wherein the lithium nickel composite oxide is represented by one or more of the following formula (i) to (iii):
Li α Ni β Co γ Mn δ O 2   (i),

wherein in formula (i), 1≤α≤1.2, β+γ+δ=1, β≥0.7, and γ≤0.2;
Li α Ni β Co γ Al δ O 2   (ii),

wherein in formula (ii), 1≤α≤1.2, β+γ+δ=1, β≥0.7, and γ≤0.2;
LiNi β Co γ Mn δ O 2   (iii),

wherein in formula (iii), 0.75≤β≤0.85, 0.05≤γ≤0.15, 0.10≤δ≤0.20.

2. The electrode according to claim 1 , characterized in that the RSm is 24 μm to 30 μm.

3. The electrode according to claim 1 , characterized in that Ls/L is 1.45 or more.

4. The electrode according to claim 1 , wherein an average particle diameter of the alumina particles is 0.005 to 10 μm.

5. A secondary battery, comprising:
a positive electrode according to claim 1 ;
a negative electrode; and
an electrolyte.

6. The secondary battery according to claim 5 , wherein an average particle diameter of the alumina particles is 0.005 to 10 μm.

7. An electrode, comprising:
a metal foil;
an electrode layer formed on at least one surface of the metal foil; and
an insulating layer formed on the electrode layer;
wherein the electrode layer includes graphite which is a negative electrode active material, and polyvinylidene fluoride (PVdF) which is a binder,
wherein the insulating layer includes alumina particles, and polyvinylidene fluoride (PVdF) which is a binder, and
wherein a boundary portion between the insulating layer and the electrode layer is in a state in which a part of the insulating layer engages into a part of the electrode layer,
Ls/L is 1.25 or more

wherein a reference length of a straight line in a direction in which the metal foil extends is taken as L and a boundary length along the boundary between the insulating layer and the electrode layer is taken as Ls, and
RSm is from 24 to 40 μm

wherein an average length of elements at the boundary between the insulating layer and the electrode layer is taken as RSm.

8. The electrode according to claim 7 , characterized in that the RSm is 24 μm to 30 μm.

9. The electrode according to claim 7 , characterized in that Ls/L is 1.45 or more.

10. The electrode according to claim 7 , wherein the electrode layer is a negative electrode active material layer.

11. The electrode according to claim 7 , wherein an average particle diameter of the alumina particles is 0.005 to 10 μm.

12. A secondary battery, comprising:
a positive electrode;
a negative electrode according to claim 7 ; and
an electrolyte.

13. The secondary battery according to claim 12 , wherein an average particle diameter of the alumina particles is 0.005 to 10 μm.

Assignees

• Nec Corp

Inventors

• Sudo Shinya
• Inoue Kazuhiko
• Yoshida Noboru
• Otohata Makihiro

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/02 Primary

  Electrodes composed of, or comprising, active material · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/8657

  layered · CPC title