Electrode, power storage device, and electronic device

Patent metadata

Field	Value
Publication number	US-9735430-B2
Application number	US-201514598344-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Jan 23, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A power storage device with high capacity or high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode includes an active material, a first binder, and a second binder. The specific surface area of the active material is S [m 2 /g]. The weight of the active material, the weight of the first binder, and the weight of the second binder are a, b, and c, respectively. The solution of {(b+c)/(a+b+c)}×100÷S is 0.3 or more. The electrode includes a first film in contact with the active material. The first film preferably includes a region in contact with the active material. The first film preferably includes a region with a thickness of 2 nm or more and 20 nm or less. The first film contains a water-soluble polymer.

First claim

What is claimed is:

1. An electrode comprising:
a current collector;
an active material;
a first film in contact with the active material, the first film containing a first binder and a second binder, and
a second film overlapping the active material with the first film interposed therebetween at a first portion of the second film and in contact with the active material at a second portion of the second film,
wherein a thickness of the second film at the first portion of the second film is thinner than a thickness of the second film at the second portion of the second film,
wherein the first binder is a water-soluble polymer,
wherein the second film contains lithium, fluorine, oxygen, and carbon,
wherein a specific surface area of the active material is S [m 2 /g],
wherein a weight of the active material, a weight of the first binder, and a weight of the second binder are a, b, and c, respectively, and
wherein A defined by Mathematical Formula 1 is 0.3 or more.

A
=

b
+
c

a
+
b
+
c

×

100
÷
S

[

Mathematical
⁢

⁢
Formula
⁢

⁢
1

]

2. The electrode according to claim 1 ,
wherein the first film includes a region with a thickness of 2 nm or more and 20 nm or less.

3. The electrode according to claim 1 ,
wherein the active material is in a form of particles, and
wherein the specific surface area S of the active material is greater than or equal to 0.2 m 2 /g and less than or equal to 7.0 m 2 /g.

4. The electrode according to claim 1 , wherein the first binder contains carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, or diacetyl cellulose.

5. The electrode according to claim 1 , wherein the second binder contains a styrene monomer or a butadiene monomer.

6. The electrode according to claim 1 , wherein the active material contains graphite.

7. A power storage device comprising:
the electrode according to claim 1 ; and
a second electrode,
wherein the electrode has a function of operating as one of a positive electrode and a negative electrode, and
wherein the second electrode has a function of operating as the other of the positive electrode and the negative electrode.

8. An electronic device comprising the power storage device according to claim 7 and a display device.

9. An electrode comprising:
a current collector;
an active material;
a first film in contact with the active material, the first film containing a first binder and a second binder, and
a second film overlapping the active material with the first film interposed therebetween at a first portion of the second film and in contact with the active material at a second portion of the second film,
wherein a thickness of the second film at the first portion of the second film is thinner than a thickness of the second film at the second portion of the second film,
wherein the first binder is a water-soluble polymer,
wherein the second film contains lithium, fluorine, oxygen, and carbon,
wherein a specific surface area of the active material is S [m 2 /g],
wherein a weight of the active material, a weight of the first binder, and a weight of the second binder are a, b, and c, respectively, and
wherein B defined by Mathematical Formula 2 is 0.3 or more.

A
=

b
+
c

a
+
b
+
c

×

100
÷
S

[

Mathematical
⁢

⁢
Formula
⁢

⁢
1

]

10. The electrode according to claim 9 , further comprising:
wherein the first film includes a region with a thickness of 2 nm or more and 20 nm or less.

11. The electrode according to claim 9 ,
wherein the active material is in a form of particles, and
wherein the specific surface area S of the active material is greater than or equal to 0.2 m 2 /g and less than or equal to 7.0 m 2 /g.

12. The electrode according to claim 9 , wherein the first binder contains carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, or diacetyl cellulose.

13. The electrode according to claim 9 , wherein the second binder contains a styrene monomer or a butadiene monomer.

14. The electrode according to claim 9 , wherein the active material contains graphite.

15. A power storage device comprising:
the electrode according to claim 9 ; and
a second electrode,
wherein the electrode has a function of operating as one of a positive electrode and a negative electrode, and
wherein the second electrode has a function of operating as the other of the positive electrode and the negative electrode.

16. An electronic device comprising the power storage device according to claim 15 and a display device.

17. An electrode comprising:
an active material;
a first film in contact with the active material, the first film containing a first binder and a second binder, and
a second film overlapping the active material with the first film interposed therebetween at a first portion of the second film and in contact with the active material at a second portion of the second film,
wherein a thickness of the second film at the first portion of the second film is thinner than a thickness of the second film at the s

Assignees

• Semiconductor Energy Lab

Inventors

• Kimura Kai
• Kuriki Kazutaka
• Oguni Teppei
• Uchida Aya

Classifications

• H01M10/0566

  Liquid materials · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01G11/38

  Carbon pastes or blends; Binders or additives therein · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/622 Primary

  being polymers · CPC title