Physical forms of MXene materials exhibiting novel electrical and optical characteristics
The present invention(s) is directed to novel conductive M n+1 X n (T s ) compositions exhibiting high volumetric capacitances, and methods of making the same. The present invention(s) is also directed to novel conductive M n+1 X n (T s ) compositions, methods of preparing transparent conductors using these materials, and products derived from these methods.
1. A method comprising,
(a) adjusting the water content of a M n+1 X n (T s ) composition to form a compressible paste wherein the ratio of water to M n+1 X n (T s ) is in a range of from about 0.3 to about 0.65 on a mass basis; and
(b) compressing the M n+1 X n (T s ) composition with a pressure in a range of from about 5 psig to about 500 psig to form a solid having a thickness in a range of from about 0.1 micron to about 100 microns;
said M n+1 X n (T s ) composition having multiple layers, each layer having a first and second surface, each layer comprising
a substantially two-dimensional array of crystal cells,
each crystal cell having an empirical formula of M n+1 X n , such that each X is positioned within an octahedral array of M,
wherein M is at least one Group 3, 4, 5, 6, or 7 metal,
wherein each X is C, N, or a combination thereof and
n=1, 2, or 3;
wherein at least one of said surfaces of the layers has surface terminations, T s , independently comprising alkoxide, alkyl, carboxylate, halide, hydroxide, hydride, oxide, sub-oxide, nitride, sub-nitride, sulfide, sulfonate, thiol, or a combination thereof;
said solid body exhibiting a volumetric capacity of at least 500 F/cm 3 up to about 2000 F/cm 3 when tested as a scan rate of 20 mV/s.
2. The method of claim 1 , wherein the compression is accomplished at least in part by rolling or compression molding.
3. The method of claim 1 , wherein the compressing is accomplished at least in part by rolling the M n+1 X n (T s ) composition between at least two roller bars.
4. The method of claim 1 , wherein the compressing of the M n+1 X n (T s ) composition is accompanied by the removal of water.
5. The method of claim 1 , wherein the solid body is electrically conductive.
6. The method of claim 1 , wherein the solid body has surface electrical resistance in a range of from about 1 micro-ohm-meters to about 10,000 micro-ohm-meters.
7. The method of claim 1 , wherein the M n+1 X n (T s ) composition comprises a plurality of M n+1 X n (T s ) flakes having at least one mean lateral dimension in a range of from about 0.5 micron to about 5 microns.
8. The method of claim 1 , wherein M is at least one Group 4, 5, 6, or 7 metal.
9. The method of claim 1 , wherein M is at least one of Hf, Cr, Mn, Mo, Nb, Sc Ta, Ti, V, W, or Zr.
10. The method of claim 1 , wherein M is Ti, and n is 1 or 2.
11. The composition of claim 1 , wherein M n+1 X n comprises Sc 2 C, Sc 2 N, Ti 2 C, Ti 2 N, V 2 C, V 2 N, Cr 2 C, Cr 2 N, Zr 2 C, Zr 2 N, Nb 2 C, Nb 2 N, Hf 2 C, Hf 2 N, Ta 2 C, Mo 2 C, Ti 3 C 2 , Ti 3 N 2 , V 3 C 2 , Ta 3 C 2 , Ta 3 N 2 , Mo 3 C 2 , (Cr 2/3 Ti 1/2 ) 3 C 2 , Ti 4 C 3 , Ti 4 N 3 , V 4 C 3 , V 4 N 3 , Ta 4 C 3 , Ta 4 N 3 , Nb 4 C 3 , or a combination thereof.
12. The method of claim 1 , the crystal cells having an empirical formula Ti 3 C 2 or Ti 2 C and wherein at least one of said surfaces of each layer is coated with surface terminations, T s , comprising alkoxide, fluoride, hydroxide, oxide, sub-oxide, sulfonate, or a combination thereof.
13. The method of claim 1 , said method providing a solid body exhibiting a volumetric capacitance in a range of about 500 F/cm 3 to about 1500 F/cm 3 , or in a range of from about 100 F/g to about 500 F/g, when tested as a scan rate of 2 mV/s.
14. A solid body prepared by the method of claim 1 .
15. A solid body prepared by the method of claim 1 , further comprising intercalated lithium ions or atoms, sodium ions or atoms, potassium ions or atoms, rubidium ions or atoms, calcium ions or atoms, magnesium ions or atoms, or a combination thereof.
16. The solid body of claim 14 , wherein the solid body exhibiting a volumetric capacitance of from about 500 F/cm 3 to about 2500 F/cm 3 , or in a range of from about 200 F/g to about 500 F/g, when tested as a scan rate of 2 mV/s.
17. An electrochemical device comprising a solid body of claim 14 .
18. A solid body having a thickness in a range of from about 0.1 micron to about 100 microns and comprising a M n+1 X n (T s ) material exhibiting a volumetric capacity greater than about 500 F/cm 3 up to about 2000 F/cm 3 ; said M n+1 X n (T s ) material comprising a composition comprising plurality of layers, each layer having a first and second surface, each layer comprising
a substantially two-dimensional array of crystal cells,
each crystal cell having an empirical formula of M n+1 X n , such that each X is positioned within an octahedral array of M,
wherein M is at least one Group 3, 4, 5, 6, or 7 metal,
wherein each X is C, N, or a combination thereof and
n=1, 2, or 3;
wherein at least one of said surfaces of the layers has surface terminations, T s , comprising alkyl, alkoxide, carboxylate, halide, hydroxide, hydride, oxide, sub-oxide, nitride, sub-nitride, sulfide, sulfonate, thiol, or a combination thereof.
19. The solid body of claim 18 , the M n+1 X n (T s ) material further comprising intercalated lithium or other metal ions.