Single crystal mixed metal oxide nanosheet material compositions, methods and applications

Patent metadata

Field	Value
Publication number	US-9580307-B2
Application number	US-201214124302-A
Country	US
Kind code	B2
Filing date	Jun 7, 2012
Priority date	Jun 9, 2011
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A nanosheet comprises a single crystal mixed metal oxide M1 x M2 y O 2 material composition that may comprise a single crystal Na x CoO 2 material composition. The nanosheet may be prepared using a sequential process sequence that includes chelated mixed metal ion sol-gel mixture formation, autocombustion, isostatic pressing, electro kinetic demixing and calcination. This particular process sequence provides single crystal nanosheets having in-plane mutually perpendicular lateral sheet dimensions greater than about 10 microns by about 200 microns, and a thickness from about 5 to about 100 nanometers.

First claim

What is claimed is:

1. A nanosheet comprising a single crystal mixed metal oxide M1 x M2 y O 2 material composition where:
M1 is an alkali metal or alkali earth metal;
M2 is a transition or post-transition metal of atomic number not greater than 78; and
x and y are independently variable within the ranges 0.3<x<1 and 0.9<y<1.1, where the nanosheet has:
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

2. The nanosheet of claim 1 wherein:
M1 is at least one alkali metal or alkali earth metal selected from the group consisting of Li, Na, K, Be, Mg, Ca and Sr; and
M2 is at least one transition metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Zn and Ni.

3. The nanosheet of claim 1 wherein:
M1 is at least one alkali metal or alkali earth metal selected from the group consisting of Li, K, Be, Mg, Ca and Sr; and
M2 is at least one transition metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Zn and Ni.

4. The nanosheet of claim 1 wherein the nanosheet has in-plane mutually perpendicular lateral sheet dimensions greater than 200 microns by 350 microns.

5. The nanosheet of claim 1 wherein the nanosheet has a lateral dimension greater than 1.8 millimeter.

6. The nanosheet of claim 1 wherein the nanosheet has a lateral dimension greater than 4.0 millimeter.

7. The nanosheet of claim 1 wherein the nanosheet consists essentially of the single crystal mixed metal oxide M1 x M2 y O 2 material composition absent a substrate.

8. The nanosheet of claim 1 wherein the nanosheet has a thickness from about 7.5 to about 47.5 nanometers.

9. The nanosheet of claim 1 wherein the nanosheet has a thickness from about 5 to about 20 nanometers.

10. A nanosheet comprising a single crystal Na x CoO 2 material composition where 0.6<x<0.9, and having:
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

11. The nanosheet of claim 10 wherein the nanosheet has in-plane mutually perpendicular lateral sheet dimensions greater than 200 microns by 350 microns.

12. The nanosheet of claim 10 wherein the nanosheet has a lateral dimension greater than 1.8 millimeter.

13. The nanosheet of claim 10 wherein the nanosheet has a lateral dimension greater than 4.0 millimeter.

14. The nanosheet of claim 10 wherein the nanosheet consists essentially of the single crystal Na x CoO 2 material composition absent a substrate.

15. The nanosheet of claim 10 wherein the nanosheet has a thickness from about 7.5 to about 47.5 nanometers.

16. The nanosheet of claim 10 wherein the nanosheet has a thickness from about 5 to about 20 nanometers.

17. A battery electrode including a nanosheet comprising a single crystal Na x CoO 2 material composition where 0.6<x<0.9, and having:
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

18. A thermoelectric device including a nanosheet comprising a single crystal Na x CoO 2 material composition where 0.6<x<0.9, and having:
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

19. A method for preparing a nanosheet comprising:
electrokinetically demixing a pressed mixed metal oxide powder comprising an M1 alkali metal or alkali earth metal and an M2 transition or post-transition metal of atomic number not greater than 78 to provide an M1 alkali metal or alkali earth metal enriched mixed metal oxide powder portion and an M1 alkali metal or alkali earth metal deficient mixed metal oxide powder portion; and
calcining the M1 alkali metal or alkali earth metal enriched mixed metal oxide powder portion to provide the nanosheet comprising a single crystal mixed metal oxide M1 x M2 y O 2 material composition wherein the single crystal mixed metal oxide M1 x M2 y O 2 material composition has:
x and y independently variable within the ranges 0.3<x<1 and 0.9<y<1.1;
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

20. The method of claim 19 wherein the method comprises a bulk fabrication method.

21. The method of claim 19 wherein the nanosheet has a thickness from about 7.5 to about 47.5 nanometers.

22. The method of claim 19 wherein the nanosheet has a thickness from about 5 to about 20 nanometers.

23. A method for preparing a nanosheet comprising:
auto-combusting an M1 alkali metal or alkali earth metal and M2 transition or post-transition metal chelated composition to provide a mixed metal oxide powder;
anisotropically pressing the mixed metal oxide powder to provide a pressed rectangular mixed metal oxide powder pellet;
electrokinetically demixing the pressed mixed metal oxide powder to provide an M1 alkali metal or alkali earth metal enriched mixed metal oxide powder portion and an M1 alkali metal or alkali earth metal deficient mixed metal oxide powder portion; and
calcining the M1 alkali metal or alkali earth metal enriched mixed metal oxide powder portion to provide the nanosheet comprising a single crystal mixed metal oxide M1 x M2 y O 2 material composition wherein the single crystal mixed metal oxide M1 x M2 y O 2 material composition nanosheet has:
x and y independently variable within the ranges 0.3<x<1 and 0.9<y<1.1;
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and
a thickness from 5 to 100 nanometers.

24. The method of claim 23 wherein the method comprises a bulk fabrication method.

25. The method of claim 23 wherein the nanosheet has a thickness from about 7.5 to about 47.5 nanometers.

26. The method of claim 23 wherein the nanosheet has a thickness from about 5 to about 20 nanometers.

27. A method for preparing a nanosheet comprising:
electrokinetically demixing a pressed Na—Co—O powder to provide a sodium enriched Na—Co—O powder portion and a sodium deficient Na—Co—O powder portion; and
calcining the sodium enriched Na—Co—O powder portion to provide a nanosheet comprising a single crystal Na x CoO 2 material composition wherein the single crystal Na x CoO 2 material composition nanosheet has:
x variable within the range 0.6<x<0.9;
in-plane mutually perpendicular lateral sheet dimensions greater than 10 microns by 200 microns; and

a thickness from 5 to 100 nanometers.

28. The method of claim 27 wherein the method comprises a bulk fabrication method.

29. The method of claim 27 wherein the nanosheet has a thickness from about 7.5 to about 47.5 nanometers.

30. The method of claim 27 wherein the nanosheet has a thickness from about 5 to about 20 nanometers.

31. A method for preparing a nanosheet comprising:
auto-combusting a sodium-cobalt chelated composition to provide a Na—Co—O powder;
anisotropically pressing the Na—Co—O powder to provide a pressed Na—Co—O powder;
electrokinetically demixing the pressed Na—Co—O powder to provide a sodium enriched Na—Co—O powder portion and a sodium deficient Na—Co—O powder portion; and
calcining the sodium enriched Na—Co—O powder portion to provide a nanosheet comprising a single

Assignees

• Aksit Mahmut
• Robinson Richard D
• Univ Cornell

Inventors

• Aksit Mahmut
• Robinson Richard D

Classifications

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• Y02P70/54

  Cross-Sectional Technologies · mapped topic

• C01P2002/72

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

• C01P2004/02

  obtained by optical microscopy · CPC title

• C30B29/22

  Complex oxides · CPC title