Negative electrode for non-aqueous electrolyte secondary cell

Patent metadata

Field	Value
Publication number	US-2016344033-A1
Application number	US-201415108060-A
Country	US
Kind code	A1
Filing date	Dec 12, 2014
Priority date	Dec 26, 2013
Publication date	Nov 24, 2016
Grant date	—

Abstract

Adhesion between particles in a negative electrode for non-aqueous secondary cells is improved for better cycle characteristics. A negative electrode for non-aqueous secondary cells contains silicon-containing particles and graphite particles as negative electrode active materials. The graphite particles have a first coating layer that contains carboxymethyl cellulose, and the first coating layer has an average thickness of 10 nm or more. The silicon-containing particles have a second coating layer that contains carboxymethyl cellulose, and the second coating layer has an average thickness of 10 nm or more.

First claim

1 . A negative electrode for a non-aqueous electrolyte secondary cell, the negative electrode comprising a negative electrode active material including silicon-containing particles and graphite particles and carboxymethyl cellulose, wherein:
the graphite particles have a first coating layer that contains carboxymethyl cellulose; and the first coating layer has an average thickness of 10 nm or more.

2 . The negative electrode according to claim 1 for a non-aqueous electrolyte secondary cell, wherein:
the silicon-containing particles have a second coating layer that contains carboxymethyl cellulose; and
the second coating layer has an average thickness of 10 nm or more.

3 . The negative electrode according to claim 1 for a non-aqueous electrolyte secondary cell, wherein a relative coverage A/B/C, where A and B are peak areas for carbon and sodium, respectively, on a surface of the graphite particles as measured by energy-dispersive X-ray analysis and C is a degree of etherification of the carboxymethyl cellulose, is 5.0×10 −4 or more.

4 . The negative electrode according to claim 1 for a non-aqueous electrolyte secondary cell, wherein the first coating layer contains styrene-butadiene rubber.

5 . The negative electrode according to claim 2 for a non-aqueous electrolyte secondary cell, wherein the second coating layer contains styrene-butadiene rubber.

6 . The negative electrode according to claim 1 for a non-aqueous electrolyte secondary cell, wherein the carboxymethyl cellulose represents 1% by mass or more and 7% by mass or less of the negative electiode active material.

7 . The negative electrode according to claim 1 for a non-aqueous electrolyte secondary cell, wherein a ratio by mass of the silicon-containing particles to the graphite particles is in a range of 1:99 to 20:80.

Assignees

• Sanyo Electric Co

Inventors

• Kasamatsu Shinji
• Wang Na
• Kato Yoshio

Classifications

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/622 Primary

  being polymers · CPC title

• H01M4/133 Primary

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

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title