Secondary battery

Patent metadata

Field	Value
Publication number	US-11699782-B2
Application number	US-202016904618-A
Country	US
Kind code	B2
Filing date	Jun 18, 2020
Priority date	Jul 20, 2012
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A secondary battery in which graphite that is an active material can occlude and release lithium efficiently is provided. Further, a highly reliable secondary battery in which the amount of lithium inserted and extracted into/from graphite that is an active material is prevented from varying is provided. The secondary battery includes a negative electrode including a current collector and graphite provided over the current collector, and a positive electrode. The graphite includes a plurality of graphene layers. Surfaces of the plurality of graphene layers are provided substantially along the direction of an electric field generated between the positive electrode and the negative electrode.

First claim

What is claimed is:

1. An active material comprising:
a graphite comprising a plurality of graphene layers; and
a film comprising one or more of silicon and phosphorous,
wherein an edge of each of the plurality of graphene layers is chemically bonded to the film by one of C—O—Si and C—O—P, and
wherein the graphite is capable of inserting and extracting lithium ions via the film.

2. The graphite according to claim 1 , wherein the graphite is highly oriented pyrolytic graphite.

3. An electrode comprising:
a current collector,
a graphite comprising a plurality of graphene layers; and
a film covering the graphite, the film comprising one or more of silicon and phosphorous,
wherein the graphite is in contact with the current collector,
wherein the graphite is natural graphite or artificial graphite,
wherein an edge of each of the plurality of graphene layers is chemically bonded to the film by one of C—O—Si and C—O—P, and
wherein the graphite is capable of inserting and extracting lithium ions via the film.

4. The electrode according to claim 3 , wherein an angle between surfaces of the plurality of graphene layers and a surface of the current collector ranges between 70° and 110°.

5. A secondary battery comprising the electrode according to claim 3 .

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Oguni Teppei
• Moriwaka Tamae
• Momo Junpei
• Tajima Ryota
• Inoue Nobuhiro

Classifications

• H01M4/366

  as layered products · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/133 Primary

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

• Y02E60/10

  Energy storage using batteries · CPC title