Electrolyte material having a nasicon structure for solid-state sodium ion batteries and method for the production thereof

Patent metadata

Field	Value
Publication number	US-2018254521-A1
Application number	US-201615758345-A
Country	US
Kind code	A1
Filing date	Aug 27, 2016
Priority date	Oct 9, 2015
Publication date	Sep 6, 2018
Grant date	—

Abstract

A method for preparing electrolyte material having a NASICON structure, based on a Na 3+x Sc x Zr 2−x (SiO 4 ) 2 (PO 4 ) compound where 0≤x<2. The method includes providing an acidic, aqueous solution which, according to a desired stoichiometry, comprises sodium, scandium and zirconium in the form of water-soluble nitrates, acetates or carbonates, and soluble silicates or orthosilicic acids or organic silicon compounds in dissolved form; subsequently adding phosphoric acid or ammonium dihydrogenphosphate or other soluble phosphates, according to the desired stoichiometry, complex zirconium dioxide phosphates forming as colloidal precipitations; and subsequently drying and calcining the mixture.

First claim

1 : A method for preparing electrolyte material having a NASICON structure, based on a Na 3+x Sc x Zr 2−x (SO 4 ) 2 (PO 4 ) compound where 0≤x<2, comprising the steps of:
providing an acidic, aqueous solution which, according to a desired stoichiometry, comprises sodium, scandium and zirconium in the form of water-soluble nitrates, acetates or carbonates, and soluble silicates or orthosilicic acids or organic silicon compounds in dissolved form;
subsequently adding phosphoric acid or ammonium dihydrogenphosphate or other soluble phosphates, according to the desired stoichiometry, complex zirconium dioxide phosphates forming as colloidal precipitations; and
subsequently drying and calcining the mixture.

2 : The method according to claim 1 , wherein the starting materials are selected according to the stoichiometry for 0≤x<2.

3 : The method according to claim 1 , wherein the mixture is dried at temperatures of between 60° C. and 120° C.

4 : The method according to claim 1 , wherein the dried mixture is calcined at temperatures of between 700° C. and 900° C.

5 : The method according to claim 1 , wherein, as a powder, the dried and calcined mixture comprises particles having a particle size, determined using a scanning electron microscope, of approximately 0.1 μm.

6 : The method according to claim 1 , wherein the dried and calcined powder is subsequently ground.

7 : The method according to claim 1 , wherein the dried, calcined and ground powder is subsequently compressed.

8 . (canceled)

9 : The method according to claim 7 , wherein the dried, calcined and ground powder is compressed at pressures of between 50 and 100 MPa.

10 - 14 . (canceled)

15 : The method according to claim 7 , wherein the compressed powder is sintered at temperatures of between 1200° and 1300° C.

16 : A sodium ion-conducting membrane comprising a Na 3+x Sc x Zr 2−x (SiO 4 ) 2 (PO 4 ) compound where 0.3≤x≤0.6, which can be prepared according to claim 1 , having an ionic conductivity of more than 1.2·10 −3 S/cm at 25° C.

17 : A sodium ion-conducting membrane comprising a Na 3+x Sc x Zr 2−x (SiO 4 ) 2 (PO 4 ) compound where 0.3≤x≤0.6, which can be prepared according to claim 1 , having an ionic conductivity of more than 3·10 −3 S/cm at 25° C.

18 : A sodium ion-conducting membrane according to claim 16 , having a density of more than 90% of a theoretical density.

19 : A sodium ion-conducting membrane according to claim 17 , having a density of more than 90% of a theoretical density.

Assignees

• Forschungszentrum Juelich Gmbh

Inventors

• Ma Qianli
• Tietz Frank
• Naqash Sahir
• Guillon Olivier

Classifications

• C01B25/26

  Phosphates (perphosphates C01B15/16) · CPC title

• C04B2235/3224

  Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide · CPC title

• C04B2235/449

  Organic acids, e.g. EDTA, citrate, acetate, oxalate · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• C04B35/16

  based on silicates other than clay {(zircon C04B35/48)} · CPC title