ELECTRODE, POWER STORAGE DEVICE, AND ELECTRONIC DEVICE

• US 20150207148A1
• Filed: 01/16/2015
• Published: 07/23/2015
• Est. Priority Date: 01/23/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Kai, KURIKI, Kazutaka, OGUNI, Teppei, UCHIDA, Aya
• Granted Patent: US 9,735,430 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0566 Liquid materials
• CPC Class Codes: H01M 10/446 Initial charging measures
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2010/4292 Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

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 [m²/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.

Claims

1. An electrode comprising:

a current collector;

an active material;

a first binder; and

a second binder,

wherein a specific surface area of the active material is S [m²/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.

2. The electrode according to claim 1, further comprising:

a first film in contact with the active material,

wherein the first film includes a region in contact with the active material,

wherein the first film includes a region with a thickness of 2 nm or more and 20 nm or less, and

wherein the first film contains a water-soluble polymer.

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 m²/g and less than or equal to 7.0 m²/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 stylene 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. A power storage device comprising:

a first electrode; and

an electrolytic solution,

wherein the first electrode includes a current collector and an active material layer,

wherein the active material layer includes an active material, a first film, and a second film,

wherein the first film includes a region in contact with the active material,

wherein the second film includes a region in contact with the first film,

wherein the first film contains a water-soluble polymer,

wherein the second film contains lithium, fluorine, oxygen, and carbon, and

wherein the electrolytic solution contains lithium, fluorine, oxygen, and carbon.

10. The power storage device according to claim 9,

wherein the active material is in a form of particles, and

wherein a specific surface area S of the active material is greater than or equal to 0.2 m²/g and less than or equal to 7.0 m²/g.

11. The power storage device according to claim 9,

wherein the water-soluble polymer contains carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, or diacetyl cellulose.

12. The power storage device according to claim 9,

wherein the first film contains a stylene monomer or a butadiene monomer.

13. The power storage device according to claim 9,

wherein the active material contains graphite.

14. The power storage device according to claim 9, further comprising a second electrode,

wherein the first electrode has a function of operating as a negative electrode,

wherein the second electrode has a function of operating as a positive electrode, and

wherein R defined by Mathematical Formula 2 is greater than or equal to 20 and less than or equal to 90.

15. An electronic device comprising the power storage device according to claim 9 and a display device.