Wet-coating of thin film lithium nickel oxides for electrochromic applications
Process for forming a multi-layer electrochromic structure, the process comprising depositing a film of a liquid mixture onto a surface of a substrate, and treating the deposited film to form an anodic electrochromic layer, the liquid mixture comprising a continuous phase and a dispersed phase, the dispersed phase comprising metal oxide particles, metal hydroxide particles, metal alkoxide particles, metal alkoxide oligomers, gels or particles, or a combination thereof having a number average size of at least 5 nm.
1. A process for preparing a multi-layer electrochromic structure, the process comprising: depositing a film of a liquid mixture comprising lithium, nickel, and at least one bleached state stabilizing element onto a surface of a substrate, and treating the deposited film to form an anodic electrochromic layer comprising a lithiated nickel oxide, wherein
(i) the atomic ratio of lithium to the combined amount of nickel and the bleached state stabilizing element in the anodic electrochromic layer is at least 0.4:1,
(ii) the atomic ratio of the amount of the bleached state stabilizing element to the combined amount of nickel and the bleached state stabilizing elements in the anodic electrochromic layer is at least 0.025:1,
(iii) the bleached state stabilizing element is selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, Sb and combinations thereof, and
(iv) the liquid mixture comprises a dispersed phase and a continuous phase, the dispersed phase comprising a dispersed species having a number average size of 5 nm to 200 nm,
wherein the dispersed species is metal oxide particles, metal hydroxide particles, metal alkoxide particles, metal alkoxide oligomers, metal alkoxide gels, or a combination thereof.
2. The process of claim 1 wherein the dispersed species has a number average size selected from the group consisting of 10 nm to 200 nm, 25 nm to 200 nm, 50 nm to 200 nm, 75 nm to 200 nm, and 100 nm to 200 nm.
3. The process of claim 1 wherein the dispersed species comprises discrete particles.
4. The process of claim 1 wherein the process further comprises
combining a lithium source material, a nickel source material and at least one bleached state stabilizing element source material in a solvent system, at least one of the lithium, nickel and bleached state stabilizing element source materials being a hydrolysable source material, and
hydrolyzing the hydrolysable source material to form the liquid mixture.
5. The process of claim 4 wherein the hydrolysable lithium source material is a metal alkoxide comprising lithium, nickel or the bleached state stabilizing element.
6. The process of claim 4 wherein the hydrolysable source material is hydrolyzed by adding water to the liquid mixture.
7. The process of claim 4 wherein the hydrolysable source material is hydrolyzed by water generated in situ in the liquid mixture.
8. The process of claim 7 wherein water is generated in situ by the addition of an acid catalyst to the liquid mixture.
9. The process of claim 4 wherein the hydrolysis rate and degree of hydrolysis of the hydrolysable source material is attenuated by adding a complexing agent to the liquid mixture.
10. The process of claim 9 wherein the complexing agent is a coordinating acid.
11. The process of claim 10 wherein the coordinating acid is ethoxyacetic acid.
12. The process of claim 4 wherein the hydrolysis rate and degree of hydrolysis of the hydrolysable source material is attenuated by adding at least 0.05 equivalents of a complexing agent per equivalent of hydrolysable lithium, nickel and bleached state stabilizing element in the liquid mixture.
13. The process of claim 1 wherein the substrate comprises a transparent conductive layer and a glass, plastic, metal, or metal-coated glass or plastic layer, and the surface of the substrate onto which the liquid mixture is deposited is a surface of the transparent conductive layer.
14. The process of claim 1 wherein the lithium component of the liquid mixture is a lithium salt of a coordination complex corresponding to the formula [M 4 (OR 2 ) 4 ] − , [M 5 (OR 2 ) 5 ] − , [M 6 (OR 2 ) 6 ] − , or [L n NiX 1 X 2 X 3 ] − wherein
L is a neutral mono- or polydentate Lewis base ligand
M 4 is B, Al, Ga, or Y,
M 5 is Ti, Zr, or Hf,
M 6 is Nb or Ta,
n is the number of neutral ligands, L, that are coordinated to Ni in the coordination complex,
each R 2 is independently hydrocarbyl, substituted hydrocarbyl, or substituted or unsubstituted hydrocarbyl silyl, and
X 1 , X 2 , and X 3 , are independently an anionic organic or inorganic ligand.
15. The process of claim 1 wherein the nickel component of the liquid mixture is derived from an organic-ligand stabilized Ni(II) complex corresponding to the formula L n NiX 4 X 5 wherein L is a neutral Lewis base ligand, n is the number of neutral Lewis ligands coordinated to the Ni center, and X 4 and X 5 are independently an organic or inorganic anionic ligand.
16. The process of claim 1 wherein the nickel component of the liquid mixture is a hydrolysable nickel composition derived from (i) nickel or a nickel-containing composition and (ii) an alcohol having the formula:
HOC(R 3 )(R 4 )C(R 5 )(R 6 )(R 7 )
wherein R 3 , R 4 , R 5 , R 6 , and R 7 are independently substituted or unsubstituted hydrocarbyl groups, at least one of R 3 , R 4 , R 5 , R 6 , and R 7 comprises an electronegative heteroatom, and where any of R 3 , R 4 , R 5 , R 6 , and R 7 can be joined together to form a ring.
17. The process of claim 1 wherein the atomic ratio of lithium to the combined amount of nickel and the bleached state stabilizing element in the liquid mixture is at least 0.4:1, the atomic ratio of the combined amount of the bleached state stabilizing element to the combined amount of nickel and the bleached state stabilizing elements in the liquid mixture is 0.025:1 to 0.8:1, and the bleached state stabilizing element in the liquid mixture is selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, Sb and combinations thereof.
18. The process of claim 1 wherein the deposited material is thermally treated at an annealing temperature of at least 200° C. and for an annealing time in the range of 5 minutes to 2 hours to form the anodic electrochromic layer.
19. A process for forming a multi-layer electrochromic structure, the process comprising:
depositing a film of a liquid mixture onto a surface of a substrate to form a deposited film, wherein the liquid mixture comprises a continuous phase and a dispersed phase, the dispersed phase comprising metal oxide particles, metal hydroxide particles, metal alkoxide particles, metal alkoxide oligomers, metal alkoxide gels, or a combination thereof having a number average size of 5 nm to 200 nm, and
treating the deposited film to form an anodic electrochromic layer comprising a nickel oxide, the anodic electrochromic layer adapted to cycle between a bleached state transmissivity of at least 70% and a darkened state transmissivity of less than 30%.
20. The process of claim 19 wherein the dispersed phase comprises a species containing lithium, nickel and/or a bleached state stabilizing element.
21. The process of claim 20 wherein the bleached state stabilizing element is selected from the group consisting of Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, Sb and combinations thereof.
22. The process of claim 20 wherein the atomic ratio of lithium to the combined amount of nickel and the bleached state stabilizing element in the liquid mixture is at least 0.4:1.
23. The process of claim 20 wherein the atomic ratio of the combined amount of the bleached state stabilizing element to the combined amount of nickel and the bleached state stabilizing element in the liquid mixture is 0.025:1 to 0.8:1.
24. The process of claim 19 wherein the anodic electrochromic layer is adapted to cycle between a bleached state transmissivity of at least 75% and said darkened state transmissivity.