Processes and materials for casting and sintering green garnet thin films

Abstract

Set forth herein are processes and materials for making ceramic thin films by casting ceramic source powders and precursor reactants, binders, and functional additives into unsintered thin films and subsequently sintering the thin films under controlled atmospheres and on specific substrates.

1 . A method for sintering a green tape, the method comprising:
 (a) providing at least one source powder;   wherein the at least one source powder is a lithium-stuffed garnet powder;   (b) modifying the at least one source powder to prepare a modified source powder;   (c) providing a slurry of the modified source powder;   (d) casting the slurry to form a green tape;   (e) drying the green tape; and   (f) sintering the green tape.   
     
     
         2 . The method of  claim 1 , wherein the amount of source powder in the green tape is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% by weight. 
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 1 , wherein the at least one source powder is selected from the group consisting of lithium-stuffed garnet, chemical precursors to lithium-stuffed garnet, and lithium stuffed garnet with aluminum oxide dopants. 
     
     
         5 . The method of  claim 1 , wherein the at least one source powder is a powder of a lithium-stuffed garnet. 
     
     
         6 . The method of  claim 1 , wherein the at least one source powder is Li x Zr 2 La 3 O 12 yAl 2 O 3 ; wherein x ranges from 5 to 9; and y ranges from 0 to 1 
     
     
         7 . The method of  claim 1 , wherein the at least one source powder is lithium-stuffed garnet. 
     
     
         8 . The method of  claim 1 , wherein the modifying the at least one source powder comprises modifying the particle size distribution of the at least one source powder. 
     
     
         9 . The method of  claim 8 , wherein the particle size distribution has a d 50  of about 100 nm, 200 nm, 300 nm, 400 nm, 1 μm, 2 μm, 3 μm, or 4 μm. 
     
     
         10 .- 22 . (canceled) 
     
     
         23 . The method of  claim 1 , wherein the surface area of the at least one source powder is increased to at least 5 m 2 /g during the modifying the at least one source powder. 
     
     
         24 . The method of claim  22 , wherein the surface area of the at least one source powder is increased to at least 8 m 2 /g and less than 15 m 2 /g during the modifying the at least one source powder. 
     
     
         25 . The method of  claim 1 , wherein the modifying the at least one source powder comprises decreasing an average particle size of particles of the at least one source powder. 
     
     
         26 .- 31 . (canceled) 
     
     
         32 . The method of  claim 1 , further comprising stress relieving the green tape prior to the sintering. 
     
     
         33 . The method of  claim 1 , further comprising laminating more than one green tape together. 
     
     
         34 . The method of  claim 1 , further comprising laminating one green tape on to a second green tape. 
     
     
         35 .- 36 . (canceled) 
     
     
         37 . The method of  claim 1 , wherein the at least one source powder is a Li-stuffed garnet compound characterized by the formula Li x La y Zr z O t .qAl 2 O 3 , wherein 4<x<10, 1<y<4, 1<z<3, 6<t<14, and 0≦q≦1. 
     
     
         38 . The method of  claim 1 , wherein the at least one source powder is a Li-stuffed garnet compound characterized by the formula Li 7-x La 3 Zr 2 O 12 .qAl 2 O 3 , wherein q is 0, 0.3, 0.35, 0.5, 0.75, or 1.0 and 0≦x≦1. 
     
     
         39 . (canceled) 
     
     
         40 . The method of  claim 1 , wherein providing the slurry comprises formulating the slurry by mixing at least two or more of:
 a solvent selected from the group consisting of methanol, MEK, ethanol, propanol, isopropanol (IPA), acetone, cyclohexanol, toluene, acetic acid, benzene, and a combination thereof;   a binder selected from the group consisting of fish oil, PVB, KD1, an acrylic acid, triton, phosphate esters, derivatives thereof, and combinations thereof;   a plasticizer selected from the group consisting of a benzyl butyl phthalate and di-butyl phthalate;   a pH modifier;   a sintering aid; and   a source powder selected from a lithium-stuffed garnet.   
     
     
         41 . (canceled) 
     
     
         42 . The method of  claim 1 , wherein the modifying comprises classifying the at least one source powder based on a particle size. 
     
     
         43 .- 44 . (canceled) 
     
     
         45 . The method of  claim 1 , wherein the slurry has a solid loading of 1% to 99 wt %, wherein the solid loading refers to the amount of source powder. 
     
     
         46 . The method of  claim 1 , wherein the slurry, when dried, has about 80% w/w source powder. 
     
     
         47 . The method of  claim 1 , wherein the slurry, when dried, has about 10-25% w/w organic content, wherein the organic content refers to slurry components other than the source powder. 
     
     
         48 . The method of  claim 1 , wherein the slurry, when dried, has about 10-25% w/w organic content, wherein the organic content refers to slurry components other than the source powder wherein the source powder is a lithium-stuffed garnet. 
     
     
         49 . The method of  claim 1 , wherein the amount of binder and plasticizer in the slurry is about 10-25% w/w organic content, wherein the organic content refers to slurry components other than the source powder wherein the source powder is a lithium-stuffed garnet. 
     
     
         50 .- 52 . (canceled) 
     
     
         53 . The method of  claim 1 , wherein the source powder is characterized by the formula Li 7.1 Zr 2 La 3 O 12 +0.5Al 2 O 3 , as batched. 
     
     
         54 . A slurry for preparing a cast green film, the slurry comprising:
 at least two or more of:
 a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, hexanol, cyclohexanone cyclohexanol, methyl acetate, ethyl acetate, methyl-ethyl ketone (MEK), acetone, toluene, hexanes, acetic acid, and combinations thereof; 
 a binder selected from the group consisting of fish oil, polyvinylbutylene (PVB), KD1, an acrylic acid, triton, phosphate esters, and combinations thereof; 
 a plasticizer selected from the group consisting of a benzyl butyl phthalate and di-butyl phthalate; 
 optionally a pH modifier; 
 optionally a sintering aid selected from MgO, Al 2 O 3 , and combinations thereof; and 
   a source powder selected from a lithium-stuffed garnet.   
     
     
         55 . The slurry of  claim 54 , wherein the amount of source powder is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% by weight. 
     
     
         56 . (canceled) 
     
     
         57 . The slurry of  claim 54 , wherein the source powder is selected from the group consisting of lithium-stuffed garnet, chemical precursors to lithium-stuffed garnet, and lithium stuffed garnet with aluminum oxide dopants. 
     
     
         58 . (canceled) 
     
     
         59 . The slurry of  claim 54 , wherein the source powder comprises garnet powder milled to d 50  of about 3 μm, and wherein the binder comprises poly methyl methacrylate in MEK. 
     
     
         60 . (canceled) 
     
     
         61 . The slurry of  claim 54 , wherein the solvent is selected from methyl-ethyl ketone (MEK) or toluene. 
     
     
         62 . The slurry of  claim 54 , wherein the solvent comprises methyl-ethyl ketone (MEK). 
     
     
         63 . The slurry of  claim 54 , wherein the solvent further comprises isopropanol (IPA). 
     
     
         64 . The slurry of  claim 54 , wherein the solvent further comprises cyclohexanone. 
     
     
         65 .- 66 . (canceled) 
     
     
         67 . The slurry of  claim 54 , wherein the solvent is an azeotrope. 
     
     
         68 . The slurry of  claim 54 , wherein the source powder is a lithium-stuffed garnet. 
     
     
         69 . The slurry of  claim 68 , wherein the amount of lithium-stuffed garnet in the slurry is at least 70% w/w. 
     
     
         70 . The slurry of  claim 54 , wherein a concentration of the source powder in the slurry is about 50 wt %, and wherein a concentration of the binder in the slurry is about 50 wt %. 
     
     
         71 . The slurry of  claim 54 , wherein a concentration of the source powder in the slurry is about 2-80% w/w. 
     
     
         72 .- 73 . (canceled) 
     
     
         74 . The slurry of  claim 54 , wherein the green film contains flocs at a density of less than 100/mm 2  where a floc is a binder aggregate 5 μm in diameter as measured by FIB cross section SEM of a green film. 
     
     
         75 . A green tape, comprising:
 a source powder, wherein the source powder is a lithium-stuffed garnet powder;   a solvent;   a binder; and   a dispersant;   wherein the green tape has a pycnometry density greater than 3.9 and less than 5.0 g·cm 3 .   
     
     
         76 . The green tape of  claim 75 , further comprising a member selected from a plasticizer, a pH modifier, and a sintering aid. 
     
     
         77 .- 78 . (canceled) 
     
     
         79 . The green tape of  claim 75 , comprising a pH modifier selected from citric acid or ammonia hydroxide. 
     
     
         80 . The green tape of  claim 75 , comprising a sintering aid selected from MgO, Al 2 O 3 , and combinations thereof. 
     
     
         81 . The green tape of  claim 75 , wherein the solvent is an azeotrope. 
     
     
         82 . (canceled) 
     
     
         83 . The green tape of  claim 75 , wherein the solvent is selected from methyl ethyl ketone (MEK), tetrahydrofuran, toluene, acetone, 1-butanol, 2-butanol, cyclohexane, cyclohexanol, ethanol, isopropanol, methanol, 1-propanol, propylene carbonate, hexane, 1-propanol, m-xylene, and pentane. 
     
     
         84 . (canceled) 
     
     
         85 . The green tape of  claim 75 , wherein the solvent comprises methyl-ethyl ketone (MEK). 
     
     
         86 . The green tape of  claim 75 , wherein the solvent further comprises isopropanol (IPA). 
     
     
         87 . The green tape of  claim 75 , wherein the solvent further comprises cyclohexanone. 
     
     
         88 . The green tape of  claim 75 , wherein the ratio of MEK:IPA is 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, or 2:8 w/w. 
     
     
         89 . The green tape of  88   claim 75 , wherein the amount of cyclohexanol is about 10-25% by weight. 
     
     
         90 . (canceled) 
     
     
         91 . The green tape of  claim 75 , comprising a source powder of a lithium-stuffed garnet having a density of 4 g/cm 3 , and a solvent comprising MEK and IPA. 
     
     
         92 . The green tape of  claim 75 , comprising a source powder of a lithium-stuffed garnet having a density of 4 g/cm 3 , and a solvent comprising MEK, IPA, and cyclohexanone. 
     
     
         93 . A method of making a green tape, comprising:
 (a) providing a slurry, wherein the slurry comprises a lithium-stuffed garnet powder;   (b) providing a binder mixture;   (c) mixing the slurry with the binder mixture to form a mixed slurry; and   (d) casting the mixed slurry to provide a green tape.   
     
     
         94 . The method of  claim 93 , wherein the slurry comprises at least two or more of:
 a solvent selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, hexanol, cyclohexanol, methyl acetate, ethyl acetate, methyl-ethyl ketone (MEK), acetone, toluene, hexanes, acetic acid, and combinations thereof;   a binder selected from the group consisting of fish oil, polyvinylbutylene (PVB), KD1, an acrylic acid, triton, phosphate esters, and derivatives thereof;   a plasticizer selected from the group consisting of a benzyl butyl phthalate and di-butyl phthalate;   optionally a pH modifier;   optionally a sintering aid; and   a source powder selected from a lithium-stuffed garnet.   
     
     
         95 .- 102 . (canceled) 
     
     
         103 . The method of  claim 93 , wherein the green tape has a solid loading greater than 50% w/w. 
     
     
         104 .- 107 . (canceled) 
     
     
         108 . The method of  claim 93 , wherein the green tape is a thin film having a film thickness less than 200 μm and greater than 1 nm. 
     
     
         109 .- 114 . (canceled) 
     
     
         115 . The method of  claim 93 , further comprising (e) drying the green tape until it has an organic content amount of about 10-25% w/w, wherein the organic content is the content other than the source powder. 
     
     
         116 . The method of  claim 93 , further comprising (f) laminating a second green tape to the green tape made in  claim 92  to make a stack of green tapes. 
     
     
         117 .- 118 . (canceled)