Porous silicon electrode and method

Patent metadata

Field	Value
Publication number	US-2017194631-A1
Application number	US-201515320686-A
Country	US
Kind code	A1
Filing date	Jun 19, 2015
Priority date	Jun 20, 2014
Publication date	Jul 6, 2017
Grant date	—

Abstract

A silicon based micro-structured material and methods are shown. In one example, the silicon based micro-structured material is used as an electrode in a battery, such as a lithium ion battery.

First claim

What is claimed is:

1 . A method of forming a battery electrode, comprising:
mixing silicon oxide powder and sodium chloride; adding a reducing agent; reducing the silicon oxide and sodium chloride mixture to produce silicon; and etching the reduced silicon to form a porous silicon microstructure.

2 . The method of claim 1 , wherein reducing the silicon oxide and sodium chloride mixture includes magnesiothermically reducing the silicon oxide and sodium chloride mixture.

3 . The method of claim 1 , wherein mixing silicon oxide powder and sodium chloride includes mixing silicon oxide powder and sodium chloride in a ratio of approximately 1:10 silicon oxide to sodium chloride by weight.

4 . The method of claim 2 , further including mixing magnesium powder with the silicon oxide powder and sodium chloride in a ratio of approximately 1:0.9 silicon oxide to magnesium by weight.

5 . The method of claim 1 , further including coating the porous silicon microstructure with a carbon coating.

6 . The method of claim 5 , wherein coating the porous silicon microstructure with a carbon coating includes coating the porous silicon microstructure with an amorphous carbon coating.

7 . A battery, comprising:
a first electrode, including:
a porous silicon material, having a specific surface area of approximately 300-350 m 2 g −1 and a pore diameter of approximately 9 nm;
a second electrode; and an electrolyte in contact with both the first electrode and the second electrode.

8 . The battery of claim 7 , further including a carbon coating covering the porous silicon material.

9 . The battery of claim 8 , wherein the first electrode includes a mixture of carbon coated porous silicon particles, acetylene black, and polyacrylic acid.

10 . The battery of claim 7 , wherein the electrolyte includes a mixture of ethylene carbonate and dimethyl carbonate.

Assignees

• Univ California

Inventors

• Favors Zachary
• Ozkan Cengiz S
• Ozkan Mihrimah

Classifications

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M4/366

  as layered products · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0525

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

• H01M4/364

  as mixtures · CPC title