Production method for producing silicon clathrate ii

Patent metadata

Field	Value
Publication number	US-2021066714-A1
Application number	US-202017002408-A
Country	US
Kind code	A1
Filing date	Aug 25, 2020
Priority date	Aug 27, 2019
Publication date	Mar 4, 2021
Grant date	—

Abstract

Provided is a novel production method for producing silicon clathrate II. In the production method for producing silicon clathrate II, in a reaction system in which a Na—Si alloy containing Na and Si and an Na getter agent coexist so as not to be in contact with each other, the Na—Si alloy is heated and Na evaporated from the Na—Si alloy is thus caused to react with the Na getter agent to reduce an amount of Na in the Na—Si alloy.

First claim

1 . A production method for producing silicon clathrate II, wherein, in a reaction system in which a Na—Si alloy containing Na and Si and an Na getter agent coexist so as not to be in contact with each other, the Na—Si alloy is heated and Na evaporated from the Na—Si alloy is thus caused to react with the Na getter agent to reduce an amount of Na in the Na—Si alloy.

2 . A production method for producing silicon clathrate II represented by composition formula Na x2 Si 136 , wherein,
in a reaction system in which silicon clathrate II represented by composition formula Na x1 Si 136 and an Na getter agent coexist so as not to be in contact with each other, the silicon clathrate II is heated and Na evaporated from the silicon clathrate II is thus caused to react with the Na getter agent to reduce an amount of Na in the silicon clathrate II, and x1 and x2 satisfy 0<x1≤24, 0≤x2<24, and x2<x1.

3 . The production method for producing the silicon clathrate II according to claim 1 or 2 , wherein heating is performed under a reduced-pressure condition.

4 . The production method for producing the silicon clathrate II according to claim 3 , wherein an air pressure P under the reduced-pressure condition satisfies 10 −2 Pa<P<10 5 Pa.

5 . The production method for producing the silicon clathrate II according to claim 1 or 2 , wherein a heating temperature is not higher than 400° C.

6 . The production method for producing the silicon clathrate II according to claim 1 or 2 , wherein the Na getter agent is selected from a metal oxide other than an alkali metal and an alkaline-earth metal, a metal sulfide other than an alkali metal and an alkaline-earth metal, and a metal halide other than an alkali metal and an alkaline-earth metal.

7 . The production method for producing the silicon clathrate II according to claim 1 or 2 , wherein the Na getter agent is selected from WO 3 , MoO 3 , ZnO, FeO, V 2 O 3 , TiO 2 , SiO, and Al 2 O 3 .

8 . A production method for producing a negative electrode active material, the production method comprising producing the silicon clathrate II by using the production method according to claim 1 or 2 .

9 . A production method for producing a negative electrode, the production method comprising:
producing the negative electrode active material by using the production method according to claim 8 ; and producing a negative electrode by using the negative electrode active material.

10 . A production method for producing a secondary battery, the production method comprising:
producing the negative electrode by using the production method according to claim 9 ; and producing a secondary battery by using the negative electrode.

Assignees

• Kk Toyota Jidoshoki
• Toyota Motor Co Ltd

Inventors

• Harata Masanori
• Yoshida Jun
• Suzuki Kazuhiro
• Kosaka Daichi
• Nakanishi Shinji

Classifications

• C01B33/06 Primary

  Metal silicides (alloys C22) · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0525

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

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title