Chemically stable solid lithium ion conductor

• US 20070148553A1
• Filed: 03/03/2005
• Published: 06/28/2007
• Est. Priority Date: 03/06/2004
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: Werner Weppner
• Inventors: Weppner, Werner
• Granted Patent: US 7,901,658 B2
• Time in Patent Office: Days
• US Class Current: 429/322
• CPC Class Codes: C01G 33/006 Compounds containing, besides niobium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01G 35/006 Compounds containing, besides tantalum, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01G 11/06 with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
• CPC Class Codes: H01G 11/50 specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: H01M 6/185 with oxides, hydroxides or oxysalts as solid electrolytes
• CPC Class Codes: H01M 8/1246 the electrolyte consisting of oxides
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention concerns chemically stable solid lithium ion conductors, processes for their production and their use in batteries, accumulators, supercaps and electrochromic devices.

Claims

1. Solid ion conductor, characterized in that it has a garnet-like crystal structure and that it has a higher ion conductivity than 3.4×

10<sup>−

6</sup> S/cm.

4. Solid ion conductor as claimed in claim 1, wherein the stoichiometric composition is

L_5+xA_xG₃₋

xM₂O₁₂

and wherein 0≦

x≦

1,

L is a monovalent alkali metal cation,

A is a divalent metal cation,

G is a trivalent cation and

M is a pentavalent cation.

12. Process for producing a solid ion conductor as claimed in claim 1, characterized in that salts and/or oxides of L, A, G and M are reacted together.

13. Process as claimed in claim 12, characterized in that the reaction takes place in a solid phase reaction.

14. Process as claimed in claim 12 for the production of a solid ion conductor wherein the stoichiometric composition is

L_5+xA_xG₃₋

xM₂O₁₂

and wherein

0’

x<

1,

L is a monovalent alkali metal cation,

A is a divalent metal cation.

G is a trivalent cation and

M is a Pentavalent cation,

characterized in that L and A are used in the form of nitrates, carbonates or hydroxides and are reacted with G₂O₃ and M₂O₅.

15. Process as claimed in claim 12, which comprises the following steps:

(a) mixing the starting materials and ball-milling, preferably using zirconium oxide balls in 2-propanol,

(b) heating the mixture from (a) in air for 2-10 h to 400-1000°

C;

(c) ball-milling, preferably using zirconium balls in 2-propanol;

(d) pressing the mixture with isostatic pressure into pellets; and

(e) sintering the pellets covered with a powder of the same composition for 10-50 h at 700-1200°

C.

16. Process as claimed in claim 15, wherein

in step (b) the mixture is heated for 6 h to 700°

C.; and

in step (e) the pellets are sintered for 24 h at 900°

C.

17. Use of a solid ion conductor as claimed in claim 1 in batteries, accumulators, supercaps, fuel cells, sensors and/or electrochromic devices such as windows, screens and facades.

18. Use as claimed in claim 17, wherein the solid ion conductor is used in the form of pellets, as a thin layer, in a crystalline or amorphous foil.

2. Solid ion conductor, characterized in that it has a garnet-like crystal structure and that it has a stoichiometric composition which is formally derived by aliovalent substitution of Li₅La₃M₂O₁₂ in which M is Nb or Ta.

3. Solid ion conductor, characterized in that it has a garnet-like crystal structure and that it has a stoichiometric composition L_5+xAyG_zM₂O₁₂, wherein

L is in each case independently an arbitrary preferably monovalent cation,

A is in each case independently a monovalent, divalent, trivalent or tetravalent cation,

G is in each case independently a monovalent, divalent, trivalent or tetravalent cation

M is in each case independently a trivalent, tetravalent or pentavalent cation,

0<

x≦

2,0≦

y≦

3,0≦

z≦

3 and

wherein 0 can be partially or completely replaced by divalent and/or trivalent anions such as e.g. N³⁻

.

5. Solid ion conductor as claimed in claim 3, wherein L is selected from Li, Na and K can in each case be the same or different.

6. Solid ion conductor as claimed in claim 5, wherein L is Li.

7. Solid ion conductor as claimed in claim 3, wherein A is selected from divalent cations preferably alkaline earth metal ions.

8. Solid ion conductor as claimed in claim 3, wherein M is selected from transition metal ions.

9. Solid ion conductor as claimed in claim 3, wherein A is selected from Ca, Sr and/or Ba and wherein M is selected from Nb and Ta.

10. Solid ion conductor as claimed in claim 8, wherein A is selected from Sr and Ba and wherein M is Ta.

11. Solid ion conductor as claimed in claim 3, characterized in that it is stable towards elemental lithium at lithium activities corresponding to a voltage of 5 V.