Method and system for the production of silicon oxide deposit

Patent metadata

Field	Value
Publication number	US-9790095-B2
Application number	US-201314360258-A
Country	US
Kind code	B2
Filing date	Feb 28, 2013
Priority date	Mar 22, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A silicon oxide deposit is continuously prepared by feeding a powder feed containing silicon dioxide powder to a reaction chamber, heating the feed at 1,200-1,600° C. to produce a silicon oxide vapor, delivering the vapor to a deposition chamber through a transfer line which is maintained at or above the temperature of the reaction chamber, for thereby causing silicon oxide to deposit on a cool substrate, and removing the silicon oxide deposit from the deposition chamber. Two deposition chambers are provided, and the step of delivering the vapor is alternately switched from one to another deposition chamber.

First claim

The invention claimed is:

1. A method for continuously preparing a silicon oxide deposit, comprising the steps of:
feeding a powder feed containing silicon dioxide powder to a reaction chamber,
heating the feed in the reaction chamber in an inert gas under normal or reduced pressure at a temperature of 1,200 to 1,600° C. to effect reaction on the feed to produce a silicon oxide vapor,
delivering the silicon oxide vapor from the reaction chamber to a deposition chamber through a transfer line, the deposition chamber having a substrate disposed therein, the substrate being cooled, the transfer line being maintained at a temperature equal to or higher than the temperature of the reaction chamber, for thereby causing silicon oxide to deposit on the substrate as a mass, and vibrating the substrate by a vibrator to remove the silicon oxide deposit from the substrate, and
removing the silicon oxide deposit from the deposition chamber when the step of delivering the silicon oxide vapor to the deposition chamber is interrupted,
wherein at least two deposition chambers and a selector mechanism for alternately switching the delivery of silicon oxide vapor from one to another deposition chamber are provided, the step of delivering the silicon oxide vapor is alternately switched from one to another deposition chamber, and the steps of delivering the silicon oxide vapor to the deposition chamber and interrupting are sequentially repeated in each of the deposition chambers, whereby the silicon oxide deposit is recovered from the at least two deposition chambers, and the step of removing the silicon oxide deposit includes interrupting the delivery of silicon oxide vapor to the deposition chamber and cooling the substrate so that the silicon oxide deposit spontaneously peels off from the substrate, the silicon oxide deposit falls from the deposition chamber into a recovery mechanism which is connected to the deposition chamber via a valve, and recovering the deposit from the recovery mechanism after the valve is closed and the recovery mechanism resumes atmospheric pressure, whereupon the silicon oxide deposit is obtained,
wherein the substrate is cooled at a rate of at least 60° C./hr for the duration from the interruption of delivery of silicon oxide vapor to the deposition chamber to the spontaneous peel-off of silicon oxide deposit.

2. The method of claim 1 , wherein the powder feed is a mixture of a silicon dioxide powder and a metal silicon powder.

3. The method of claim 1 , wherein the substrate in the deposition chamber is cooled to a temperature of up to 1,000° C.

4. The method of claim 1 , wherein the step of delivering the silicon oxide vapor is alternately switched from one to another deposition chamber whenever the mass of silicon oxide deposited on the substrate reaches a thickness of 2 to 100 mm.

5. The method of claim 1 , wherein the silicon oxide vapor is delivered to the deposition chamber at a flow rate of 0.5 to 50 kg/m 2 /hr relative to the surface area of the substrate in the deposition chamber.

6. The method of claim 1 , wherein the silicon oxide deposit has a BET specific surface area of 0.5 to 30 m 2 /g.

7. The method of claim 1 , wherein the silicon oxide deposit is used as negative electrode active material in lithium ion secondary batteries.

8. The method of claim 1 , wherein the substrate is cooled at a rate of at least 120° C./hr.

9. The method of claim 1 , wherein the substrate is cooled at a rate of at least 200° C./hr.

10. A system for preparing a silicon oxide deposit, comprising:
a feed mechanism for feeding a powder feed containing silicon dioxide powder to a reaction chamber;
the reaction chamber for effecting reaction on the powder feed to produce a silicon oxide vapor;
at least two deposition chambers in which only a substrate is disposed, where the silicon oxide vapor is deposited on the substrate;
a cooling mechanism for cooling each substrate;
a transfer line for delivering the silicon oxide vapor from the reaction chamber to each deposition chamber;
a selector mechanism for alternately switching the delivery of silicon oxide vapor between the deposition chambers; and
a recovery mechanism for removing the silicon oxide deposit from each substrate, and
a mechanism that vibrates the substrate, wherein
the selector mechanism comprises at least two valves and a vacuum pump, the vacuum pump being connected to each of the deposition chambers via one of the at least two valves, and
the recovery mechanism is connected to the deposition chamber via another valve.

Assignees

• Shinetsu Chemical Co

Inventors

• Nishimine Masanobu
• Fukuoka Hirofumi

Classifications

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• C01B33/113 Primary

  Silicon oxides; Hydrates thereof {(preparing monoxide by reduction of siliceous material C01B33/182)} · CPC title

• H01M10/0525

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

• Y02E60/10

  Energy storage using batteries · CPC title