Graphene and power storage device, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-10461332-B2
Application number	US-201414507872-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Sep 30, 2011
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

First claim

What is claimed is:

1. An electrode for a lithium ion battery comprising:
a current collector; and
an active material layer over the current collector, the active material layer comprising:
a particle of an active material comprising an alkali metal; and
a graphene comprising hydrogen atoms, carbon atoms and oxygen atoms,

wherein the graphene is a one-atom-thick sheet or a stack of 2 to 100 layers of the sheet,
wherein the graphene has a two-dimensional structure and has a sheet-like shape,
wherein a proportion of the carbon atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 80% and lower than 90%,
wherein a proportion of the oxygen atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 10% and lower than 20%,
wherein a sum of the proportion of the carbon atoms and the proportion of the oxygen atoms is lower than 100%,
wherein, in bonds of the carbon atoms, a proportion of sp 2 -bonded carbon atoms among the carbon atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 50% and lower than or equal to 80%, and
wherein the graphene and the particle of the active material are randomly dispersed in the active material layer.

2. A power storage device comprising:
an electrolyte comprising a lithium salt; and
an electrode according to claim 1 .

3. An electrode comprising:
a current collector; and
an active material layer over the current collector, the active material layer comprising:
a particle of an active material comprising an alkali metal; and
a material comprising:
hydrogen atoms;
carbon atoms whose proportion measured by X-ray photoelectron spectroscopy is higher than or equal to 80% and lower than or equal to 90%; and
oxygen atoms whose proportion measured by X-ray photoelectron spectroscopy is higher than or equal to 10% and lower than or equal to 20%,

wherein the material is a one-atom-thick sheet or a stack of 2 to 100 layers of the sheets,
wherein the material has a two-dimensional structure and has a sheet-like shape, and
wherein a proportion of sp 2 -bonded carbon atoms of the carbon atoms is higher than or equal to 50% and lower than or equal to 80%, and
wherein the material and the particle of the active material are randomly dispersed in the active material layer.

4. A power storage device comprising:
the electrode according to claim 3 ;
an electrolyte; and
a separator.

5. The power storage device according to claim 4 , wherein the electrolyte is an aprotic organic solvent.

6. A power storage device comprising:
an electrolyte comprising lithium salt; and
an electrode comprising:
a current collector; and
an active material layer over the current collector, the active material layer comprising:
a particle of an active material; and
a graphene comprising hydrogen atoms, carbon atoms and oxygen atoms,

wherein the graphene is a one-atom-thick sheet or a stack of 2 to 100 layers of the sheet,
wherein the graphene has a two-dimensional structure and has a sheet-like shape,
wherein a proportion of the carbon atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 80% and lower than 90%,
wherein a proportion of the oxygen atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 10% and lower than 20%,
wherein a sum of the proportion of the carbon atoms and the proportion of the oxygen atoms is lower than 100%,
wherein, in bonds of the carbon atoms, a proportion of sp 2 -bonded carbon atoms among the carbon atoms measured by X-ray photoelectron spectroscopy is higher than or equal to 50% and lower than or equal to 80%, and
wherein the graphene and the particle of the active material are randomly dispersed in the active material layer.

7. The electrode according to claim 1 ,
wherein the active material comprises an olivine-type lithium-containing phosphate.

8. The electrode according to claim 3 ,
wherein the active material comprises an olivine-type lithium-containing phosphate.

9. The electrode according to claim 6 ,
wherein the active material comprises an olivine-type lithium-containing phosphate.

10. The electrode according to claim 1 ,
wherein the graphene covers the particle of the active material.

11. The electrode according to claim 3 ,
wherein the material covers the particle of the active material.

12. The power storage device according to claim 6 ,
wherein the graphene covers the active material.

13. The electrode according to claim 1 ,
wherein a size of the particle of the active material is 20 nm or more and 100 nm or less.

14. The electrode according to claim 1 ,
wherein a thickness of the electrode is in a range of 20 μm to 100 μm.

Assignees

• Semiconductor Energy Lab

Inventors

• Todoriki Hiroatsu
• Saito Yumiko
• Kawakami Takahiro
• Nomoto Kuniharu
• Yukawa Mikio

Classifications

• H01M4/0438

  by electrochemical processing (electroless electrochemical plating C23C18/54) · CPC title

• C01B32/23

  Oxidation · CPC title

• C01B32/192

  starting from graphitic oxides · CPC title

• H01M4/587 Primary

  for inserting or intercalating light metals · CPC title

• H01M4/1393

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