POWER STORAGE DEVICE

• US 20150086860A1
• Filed: 09/18/2014
• Published: 03/26/2015
• Est. Priority Date: 09/26/2013
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YOKOI, Rie, ISHIKAWA, Jun, OGUNI, Teppei, SEO, Satoshi, MORIWAKA, Tamae, KIMURA, Kai
• Application Number:
  US14/489,938
• Publication Number:
  US 20150086860A1
• Time in Patent Office: Days
• US Class Current: 429/188
• 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 10/0568 characterised by the solutes
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power storage device with reduced initial irreversible capacity is provided. The power storage device includes a positive electrode, a negative electrode, and an electrolyte solution. The negative electrode includes a negative electrode active material and a water-soluble polymer. The electrolyte solution includes an ionic liquid. The ionic liquid includes a cation and a monovalent amide anion.

Claims

1. A power storage device comprising:

a positive electrode;

a negative electrode comprising a negative electrode active material and a water-soluble polymer; and

an electrolyte solution comprising an ionic liquid between the positive electrode and the negative electrode,

wherein the ionic liquid comprises a cation and a monovalent amide anion.

3. The power storage device according to claim 1, wherein the water-soluble polymer is polysaccharide.

6. The power storage device according to claim 1, wherein the monovalent amide anion is an anion represented by (C_nF_2n+1SO₂)₂N⁻

or CF₂(CF₂SO₂)₂N⁻

, n being greater than or equal to 0 and less than or equal to 3.

8. The power storage device according to claim 1, further comprising a coating film on a surface of the negative electrode,

wherein a ratio of a proportion of oxygen to a proportion of fluorine (O/F) in the coating film is greater than or equal to 0.1 and less than or equal to 2.

10. The power storage device according to claim 1, further comprising a coating film on a surface of the negative electrode,

wherein the electrolyte solution comprises a lithium ion,

wherein the coating film comprises lithium fluoride and lithium carbonate, and

wherein a weight ratio of the lithium carbonate to the lithium fluoride (lithium carbonate/lithium fluoride) in the coating film is less than or equal to 2.

12. The power storage device according to claim 1, wherein in a C1s spectrum obtained by X-ray photoelectron spectroscopy, a maximum value in a range from 290 eV to 292 eV inclusive is less than or equal to 0.3 times a maximum value in a range from 284.5 eV to 286 eV inclusive.

14. The power storage device according to claim 1, wherein the negative electrode active material is a carbon material.

16. The power storage device according to claim 14, wherein the carbon material is at least one selected from natural graphite, artificial graphite, mesophase pitch-based carbon fiber, isotropic pitch-based carbon fiber, and graphene.

2. A power storage device comprising:

a positive electrode;

a negative electrode comprising a negative electrode active material, a first material, and a second material; and

an electrolyte solution comprising an ionic liquid between the positive electrode and the negative electrode,

wherein the first material comprises a material having rubber elasticity,

wherein the second material comprises a water-soluble polymer, and

wherein the ionic liquid comprises a cation and a monovalent amide anion.

4. The power storage device according to claim 2, wherein the water-soluble polymer is polysaccharide.

5. The power storage device according to claim 2, wherein the material having rubber elasticity is a polymer including a styrene monomer unit or a butadiene monomer unit.

7. The power storage device according to claim 2, wherein the monovalent amide anion is an anion represented by (C_nF_2n+1SO₂)₂N⁻

or CF₂(CF₂SO₂)₂N⁻

, n being greater than or equal to 0 and less than or equal to 3.

9. The power storage device according to claim 2, further comprising a coating film on a surface of the negative electrode,

wherein a ratio of a proportion of oxygen to a proportion of fluorine (O/F) in the coating film is greater than or equal to 0.1 and less than or equal to 2.

11. The power storage device according to claim 2, further comprising a coating film on a surface of the negative electrode,

wherein the electrolyte solution comprises a lithium ion,

wherein the coating film comprises lithium fluoride and lithium carbonate, and

wherein a weight ratio of the lithium carbonate to the lithium fluoride (lithium carbonate/lithium fluoride) in the coating film is less than or equal to 2.

13. The power storage device according to claim 2, wherein in a C1s spectrum obtained by X-ray photoelectron spectroscopy, a maximum value in a range from 290 eV to 292 eV inclusive is less than or equal to 0.3 times a maximum value in a range from 284.5 eV to 286 eV inclusive.

15. The power storage device according to claim 2, wherein the negative electrode active material is a carbon material.

17. The power storage device according to claim 15, wherein the carbon material is at least one selected from natural graphite, artificial graphite, mesophase pitch-based carbon fiber, isotropic pitch-based carbon fiber, and graphene.