Green body and method for forming same

Abstract

In one aspect, the present invention provides a green body for forming a solid-state electrolyte (SSE). The green body includes an LLZO material and a binder. In another aspect, a method for forming a green body for an SSE is provided. The green body includes an LLZO material and a binder. The green body has a density of at least about 87.5%. In some embodiments, the green body has a density of at least about 90%. In other embodiments, the green body has a density of at least about 92.5%.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 384,123, filed November 17, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] Government Licensing Rights This invention was made with government support under Contract No. SP4701-20-F-0115 awarded by the Defense Logistics Agency. The United States Government has certain rights in this invention.

[0003] The present invention provides a green body for forming a solid electrolyte and a method for forming the same. [Background technology]

[0004] Solid-state batteries can include a dense solid electrolyte (SSE) separator layer containing a lithium lanthanum zirconium oxide (LLZO) material. The SSE separator layer prevents electronic conduction and allows ionic conduction between the anode and cathode. The SSE separator layer must have sufficiently low porosity so that the relative density of the SSE separator layer is close to the theoretical density of the SSE separator layer. This ensures that there are no open paths for anolyte and / or catholyte leaching or the formation or propagation of lithium dendrites.

[0005] The SSE separator layer is formed from a green body. The green body is used as an intermediate to form the loose LLZO powder into the desired macroscopic structure and microscopically position the LLZO powder so that it can be fully densified during sintering. Green body SSE materials are formed by first reacting (e.g., calcining) multiple precursor powders, followed by additional processing steps. The prepared LLZO powder is then formed into a green body by combining the powder with a binder (e.g., a polymer binder). Standard industrial processes for green body formation (e.g., tape casting) typically require one or more solvents or other additives. However, for reactive materials like LLZO, it has been found that the solvents or additives used in green body formation react with the LLZO material to form phase impurities. In the case of LLZO materials, one of the primary phase impurities is a protonated form of LLZO (i.e., LiHLZO), which has a substantially lower density.

[0006] The formed green body undergoes a debinding process in which the binder and other organic components are substantially removed from the green body. The green body further undergoes a sintering process in which pore removal and grain growth occur. Thus, the green body inevitably reduces in size (i.e., shrinks) as a result of pore removal during sintering. Phase changes may also occur during sintering due to underlying impurities (e.g., phase impurities) in the green body, which can substantially change the density.

[0007] Green bodies that exhibit minimal shrinkage upon sintering are desirable. In particular, reduced shrinkage improves product control and predictability, including the uniformity and dimensions of sintered products (e.g., SSE separator layers, bilayers, etc.). Reduced shrinkage also allows for increased production efficiency by allowing more green bodies to be loaded into the sintering equipment (e.g., furnace) at one time. Shrinkage is directly affected by density changes. Therefore, phase impurities generated during green body formation that affect density can also affect the amount of shrinkage observed during debinding and sintering. The formation of LiHLZO and other impurities during green body formation reduces the density of the LLZO powder and the density of the green body. Upon debinding and sintering, the decomposition of LiHLZO increases density, thus resulting in greater area and volume shrinkage. SSE green bodies free of phase impurities minimize density changes and shrinkage during debinding and sintering, allowing for greater process control and efficiency.

[0008] Therefore, there remains a need to provide improved SSE green bodies for reactive materials such as LLZO. Summary of the Invention [Means for solving the problem]

[0009] In one aspect, the present invention provides a green body for forming a solid state electrolyte (SSE).

[0010] In another aspect, a green body for forming a solid electrolyte (SSE) is provided. The green body includes an LLZO material and a binder. The green body has a percent density of at least about 87.5%. In some embodiments, the green body has a percent density of at least about 90%. In other embodiments, the green body has a percent density of at least about 92.5%. In some embodiments, the green body has a percent density of at least about 95%. And, in some embodiments, the green body has a percent density of at least about 97.5%. In some embodiments, the green body (e.g., a hardened SSE green body) has a percent density of about 88.5% to about 99.99% (e.g., about 89% to about 99%).

[0011] In some embodiments, the LLZO material comprises LLZO powder, doped LLZO powder, or any combination thereof. In other embodiments, the LLZO material comprises LLZO powder. Also, in some embodiments, the LLZO material comprises doped LLZO powder. In other embodiments, the LLZO material is sintered.

[0012] In some embodiments, the doped LLZO powder comprises Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof.

[0013] In some embodiments, the doped LLZO powder has Formula (I): M1 7-x D1 a M2 3-y D2 b M3 2-z D3 c O 12-w D4 d (I) The composition comprises: During the ceremony, M1 is Li, M2 is La, M3 is Zr, D1 is Be, B, Al, Fe, Zn, Ga, Ge, or any combination thereof; D2 is Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Zn, Ce, or any combination thereof; D3 is Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Ce, Eu, Te, Y, Sr, Ca, Ba, Gd, Ge, or any combination thereof; and D4 is F, Cl, Br, I, S, Se, Te, N, P, or any combination thereof; however, 0≦w≦2, -0.5 <x≦3、 0≦y≦3, 0≦z≦2, 0≦a≦2, 0≦b≦3, 0≦c≦2, and 0≦d≦2, where at least one of a, b, c, and d is greater than 0.

[0014] In some embodiments, the LLZO material has a D90 particle size of less than about 10 μm, in other embodiments, the LLZO material has a D90 particle size of less than about 5 μm, and in some embodiments, the LLZO material has a D90 particle size of less than about 2.5 μm.

[0015] In some embodiments, the binder is cured by exposure to ultraviolet (UV) radiation. In other embodiments, the cured binder comprises a crosslinked polymeric material.

[0016] In some embodiments, the green body has a thickness of about 500 μm to about 100 μm. In some embodiments, the green body has a thickness of about 1 μm to about 100 μm. In other embodiments, the green body has a thickness of about 1 μm to about 75 μm. In some embodiments, the green body has a thickness of about 1 μm to about 50 μm. In some embodiments, the green body has a thickness of about 1 μm to about 25 μm. In other embodiments, the green body has a thickness of about 1 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 60 μm.

[0017] In some embodiments, the green body further comprises a first layer and a second layer at least partially disposed on the first layer. In such embodiments, the LLZO material is further defined as a first LLZO material and the binder is further defined as a first binder. The first layer comprises the first LLZO material and the first binder. The second layer comprises the second LLZO material and the second binder.

[0018] In some embodiments, the second layer further comprises a pore-former, hi other embodiments, the first layer is substantially free of a pore-former.

[0019] In some embodiments, the first layer has a thickness of about 500 nm to about 100 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 100 μm. In other embodiments, the first layer has a thickness of about 1 μm to about 75 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 50 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 25 μm.

[0020] In some embodiments, the second layer has a thickness of from about 500 nm to about 100 μm. In some embodiments, the second layer has a thickness of from about 1 μm to about 100 μm. In other embodiments, the second layer has a thickness of from about 1 μm to about 80 μm. In some embodiments, the second layer has a thickness of from about 20 μm to about 80 μm. Also, in some embodiments, the second layer has a thickness of from about 20 μm to about 60 μm.

[0021] One aspect of the present invention is, with respect to the weight of the SSE material, (i) less than about 10 wt% of LiHLZO, (ii) the doped LLZO material of the following formula (V) Li 7-x B a La 3-y C b Zr 2-z D c O 12 (V), and provides a sintered SSE material comprising more than 90 wt% of the doped LLZO material of the following formula (V) with respect to the weight of the SSE material, wherein, B is Al or Ga, C is Ca, Sr, Ba, or Mg, D is Ta, Nb, W, Mo, or Ti, -0.5 < x ≦ 1, 0 < a < 0.24, 0 < y ≦ 0.5, 0 < b ≦ 0.5, 0 < z ≦ 1, and 0 < c ≦ 1, wherein x, a, y, b, z, and c are independent of each other.

[0022] In some embodiments, 0.2 ≦ x 0.8, 0 < a ≦ 0.15, 0 < y ≦ 0.3, 0 < b ≦ 0.3, 0 < z ≦ 1, and 0 < c ≦ 1.

[0023] In some embodiments, x is from 0.15 to 0.7.

[0024] In some embodiments, B is Al and a is 0.05 to 0.15, for example, x is 0.15 to 0.7, B is Al, and a is 0.05 to 0.15.

[0025] In some embodiments, B is Ga and a is 0.05 to 0.8, for example, x is 0.15 to 0.7, B is Ga, and a is 0.05 to 0.8.

[0026] In some embodiments, y is 0.05 to 0.30. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, and y is 0.05 to 0.30. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, and y is 0.05 to 0.30.

[0027] In some embodiments, C is Ca and b is 0.05 to 0.25. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.25. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.25.

[0028] In some embodiments, C is Ba and b is 0.05 to 0.10. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.10. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, and b is 0.05 to 0.10.

[0029] In some embodiments, C is Sr and b is 0.25 to 0.30. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30.

[0030] In some embodiments, C is Mg and b is 0.22 to 0.28. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28.

[0031] In some embodiments, z is 0.50 to 1. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1.

[0032] In some embodiments, D is Ta and c is 0.4 to 0.6. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15-0.7, B is Al, a is 0.05-0.15, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15-0.7, B is Ga, a is 0.05-0.8, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6.

[0033] In some embodiments, D is Nb and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4.

[0034] In some embodiments, D is Ti and c is 0.8 to 1.0. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0.

[0035] In some embodiments, D is W and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4.

[0036] In some embodiments, the sintered SSE material (e.g., some of the embodiments and examples described herein) includes a dense layer and a porous layer, and the dense layer has a density ratio that is at least about 1.5% higher than the density ratio of the porous layer. For example, the dense layer has a density ratio that is at least about 2% greater than the density ratio of the porous layer.

[0037] In some embodiments, the sintered SSE material (e.g., some of the embodiments and examples described herein) includes a dense layer and a porous layer, and the dense layer or the porous layer has a thickness of about 500 nm to about 1000 μm.

[0038] One aspect of the present invention provides a green body for forming a solid electrolyte (SSE), where the green body includes an LLZO material containing less than about 10 wt% of LiHLZO with respect to the weight of the LLZO material, and a binder, and the green body includes about 30% to about 60% of the binder with respect to the volume of the green body.

[0039] In some embodiments, the LLZO material is calcined.

[0040] In some embodiments, the LLZO material (e.g., the calcined material) has the formula (V): Li 7-x B a La 3-y C b Zr 2-z D c O 12 (V), comprises a composition of wherein B is Al or Ga, C is Ca, Sr, Ba, or Mg, D is Ta, Nb, W, Mo, or Ti, -0.5 < x ≦ 1, 0 < a < 0.24, 0 < y ≦ 0.5, 0 < b ≦ 0.5, 0 < z ≦ 1, and 0 < z ≤ 1, where x, a, y, b, z, and c are independent of each other.

[0041] In some embodiments, x is from 0.15 to 0.7.

[0042] In some embodiments, B is Al and a is from 0.05 to 0.15. For example, x is from 0.15 to 0.7, B is Al, and a is from 0.05 to 0.15.

[0043] In some embodiments, B is Ga and a is from 0.05 to 0.8. For example, x is from 0.15 to 0.7, B is Ga, and a is from 0.05 to 0.8.

[0044] In some embodiments, y is from 0.05 to 0.30. For example, x is from 0.15 to 0.7, B is Al, a is from 0.05 to 0.15, and y is from 0.05 to 0.30. In other examples, x is from 0.15 to 0.7, B is Ga, a is from 0.05 to 0.8, and y is from 0.05 to 0.30.

[0045] In some embodiments, C is Ca and b is from 0.05 to 0.25. For example, x is from 0.15 to 0.7, B is Al, a is from 0.05 to 0.15, y is from 0.05 to 0.30, C is Ca, and b is from 0.05 to 0.25. In other examples, x is from 0.15 to 0.7, B is Ga, a is from 0.05 to 0.8, y is from 0.05 to 0.30, C is Ca, and b is from 0.05 to 0.25.

[0046] In some embodiments, C is Ba and b is from 0.05 to 0.10. For example, x is from 0.15 to 0.7, B is Al, a is from 0.05 to 0.15, y is from 0.05 to 0.30, C is Ca, and b is from 0.05 to 0.10. In other examples, x is from 0.15 to 0.7, B is Ga, a is from 0.05 to 0.8, y is from 0.05 to 0.30, C is Ba, and b is from 0.05 to 0.10.

[0047] In some embodiments, C is Sr and b is 0.25 to 0.30. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30.

[0048] In some embodiments, C is Mg and b is 0.22 to 0.28. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28.

[0049] In some embodiments, z is 0.50 to 1. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1.

[0050] In some embodiments, D is Ta and c is 0.4 to 0.6. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15-0.7, B is Al, a is 0.05-0.15, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15-0.7, B is Ga, a is 0.05-0.8, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, and c is 0.4 to 0.6.

[0051] In some embodiments, D is Nb and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4.

[0052] In some embodiments, D is Ti and c is 0.8 to 1.0. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0.

[0053] In some embodiments, D is W and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4.

[0054] In some embodiments, at least about 90% of the LLZO material has a cubic phase.

[0055] In some embodiments, at least about 90% of the LLZO material has a tetragonal phase.

[0056] In some embodiments, the binder comprises a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof.

[0057] In some embodiments, the binder in the green body is at least partially cured.

[0058] In some embodiments, the green body further comprises a dispersing agent or an initiator. For example, the green body comprises an initiator, and the initiator is 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropane, 1-hydroxy-cyclohexylphenylketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2, The photoinitiator may include 4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoic acid ester, ethyl 4-(dimethylamino)benzoate, or any combination thereof. In another example, the green body includes a dispersant, and the dispersant includes fish oil, a fatty acid ester, a sulfonated fatty acid, or any combination thereof.

[0059] In some embodiments, the LLZO material comprises less than about 5 wt% LiHLZO based on the weight of the LLZO material.

[0060] In some embodiments, the green body further comprises a dense layer and a porous layer, the dense layer having a density rate that is at least 1% higher than the density rate of the porous layer.

[0061] In some embodiments, the porous layer is disposed over at least a portion of the dense layer.

[0062] In some embodiments, the porous layer further comprises a pore-former and the dense layer is substantially free of any pore-former.

[0063] Another aspect of the present invention provides a method of forming an SSE green body for a solid electrolyte, the method comprising: (a-1) reacting a precursor mixture to form an LLZO material, wherein: (i) lithium-containing compounds, (ii) lanthanum-containing compounds, and (iii) forming a zirconium-containing compound; (b-1) mixing the LLZO material with a binder composition (e.g., a curable binder composition) to form a curable SSE mixture; (c-1) forming a curable green body from the curable SSE mixture; (d-1) curing the curable green body to form an SSE green body.

[0064] In some embodiments, the precursor further comprises (iv) a dopant, for example, Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof.

[0065] In some embodiments, the lithium-containing compound comprises Li2O, LiOH, LiOH·H2O, LiCl, Li2CO3, LiNO3, or any combination thereof.

[0066] In some embodiments, the lanthanum-containing compound comprises La2O3, La(OH)3, LaCl3, La2(CO3)3, La(NO3)3, or any combination thereof.

[0067] In some embodiments, the zirconium-containing compound includes ZrO2, Zr(OH)4, ZrCl4, Zr(OH)2CO3·ZrO2, Zr(NO3)4.

[0068] In some embodiments, the reacting step (a-1) further comprises reacting the precursor mixture by calcination to form the LLZO material. For example, the calcination may be carried out at a temperature of about 700°C to about 1,100°C. In other embodiments, the calcination is carried out at a temperature of about 800°C to about 1,000°C. In some embodiments, the calcination is carried out at a temperature of about 850°C to about 950°C.

[0069] In some embodiments, the method further (or optionally) comprises: (e-1) dry-milling the LLZO material to form a pulverized LLZO material (or LLZO powder).

[0070] In some embodiments, the dry-milling step (e-1) is carried out before the mixing step (b-1). In some embodiments, the dry-milling step (e-1) further comprises: (e1-1) mixing the LLZO material with a grinding additive; (e2-1) dry-milling the LLZO material to form a pulverized LLZO material.

[0071] In some embodiments, the dry-milling step (e-1) is carried out before the mixing step (b-1). In some embodiments, the dry-milling step (e-1) further comprises: (e2-1a) dry-milling an LLZO material without using a grinding additive to form a ground LLZO material.

[0072] An additional method for forming a pure-phase milled LLZO material includes wet-milling the LLZO material in a non-reactive medium (e.g., a non-reactive liquid milling medium), with or without grinding additives. Another method for forming a pure-phase milled LLZO material includes wet-milling in a reactive solvent, with or without grinding additives, followed by further processing of the powder to remove phase impurities while maintaining the desired particle size. In some cases, the further processing includes heat treatment under a suitable gas atmosphere.

[0073] In some embodiments, the grinding additive comprises a starch, a fatty acid, a fatty acid salt, an active polymeric dispersant, or any combination thereof. For example, the grinding additive can comprise a starch. In some embodiments, the starch comprises corn starch, potato starch, tapioca starch, arrowroot starch, wheat starch, potato starch, or any combination thereof.

[0074] In some embodiments, the grinding additive comprises a fatty acid, for example, α-linolenic acid, stearidonic acid, eicosapentaenoic acid, cervonic acid, linoleic acid, linolelaidic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid, docosatetraenoic acid, palmitoleic acid, vaccenic acid, paulic acid, oleic acid, elaidic acid, gondoic acid, erucic acid, nervonic acid, mead acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, or the like. The fatty acids may include, for example, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, he)icosylic acid, behenic acid, tricosylic acid, lignoceric acid, pentacosylic acid, cerotic acid, carboseric acid, montanic acid, nonacosylic acid, melissic acid, hentriacontylic acid, lacceroic acid, psyllic acid, geddic acid, ceroplastic acid, hexatriacontylic acid, heptatriacontylic acid, octatriacontylic acid, nonatriacontylic acid, tetracontylic acid, or any combination thereof.

[0075] In some embodiments, the grinding additive comprises a fatty acid salt. For example, the fatty acid salt can comprise a lithium fatty acid salt, a sodium fatty acid salt, a potassium fatty acid salt, an ammonium fatty acid salt, or any combination thereof.

[0076] In some embodiments, step (e1-1) is performed before step (e2-1). In other embodiments, step (e1-1) is performed simultaneously with step (e2-1). In some embodiments, dry-milling step (e-1) is performed in a jet mill or an attrition mill. For example, dry-milling step (e-1) is performed in a jet mill. In other embodiments, dry-milling step (e-1) is performed in an attrition mill.

[0077] In some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 10 μm. In other embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 5 μm. Also, in some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 2.5 μm. In some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 1.5 μm. In some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 1.0 μm. In some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 0.5 μm. Also, in some embodiments, the ground LLZO material (or LLZO powder) has a D90 particle size of less than about 0.3 μm.

[0078] In some embodiments, the binder composition comprises a binder (eg, a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof).

[0079] In some embodiments, the binder composition comprises a binder (e.g., a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof) and an initiator. For example, the binder composition comprises a binder and an initiator, and at least a portion of the binder composition undergoes polymerization and / or crosslinking when the curable green body is cured with UV radiation, heat, electron beam (e-beam) radiation, or a combination thereof.

[0080] In some embodiments, the binder composition comprises (i) at least one monomer, at least one oligomer, or at least one polymer, and (ii) at least one of an initiator and a dispersant, wherein at least a portion of the binder composition forms a polymer or crosslinked polymer material upon curing (e.g., curing with ultraviolet (UV) radiation, heat, electron beam (e-beam) radiation, or any combination thereof). In some examples, the curable SSE mixture comprises an LLZO material (e.g., any of the LLZO materials described herein) and a binder composition, the binder composition comprising (i) at least one monomer, at least one oligomer, or at least one polymer, and (ii) an initiator (e.g., a photoinitiator). In some examples, the curable SSE mixture comprises (i) at least one monomer, at least one oligomer, or at least one polymer, (ii) an initiator (e.g., a photoinitiator), and (iii) a dispersant.For example, the curable SSE mixture may comprise (i) at least one monomer, at least one oligomer, or at least one polymer; (ii) 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexylphenylketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one), 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2 ... ,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoic acid ester, ethyl 4-(dimethylamino)benzoate, or any combination thereof; and (iii) a dispersing agent.

[0081] In some embodiments, the binder composition comprises a crosslinkable polymeric material and an initiator (e.g., a photoinitiator). In some embodiments, the binder composition comprises a dispersant, a plasticizer, or any combination thereof.

[0082] In some embodiments, the forming step (c-1) further comprises casting a layer of the curable SSE mixture onto a substrate, the layer having a thickness of from about 750 nm to about 1000 μm.

[0083] Some embodiments further include casting a second layer comprising a second SSE mixture substantially over the first layer, the second SSE mixture comprising a pore former.

[0084] In some embodiments, the curing step (d-1) further comprises curing the curable green body with ultraviolet (UV) radiation, heat, electron beam (e-beam) radiation, or any combination thereof to form an SSE green body. In other embodiments, the curing step (d-1) comprises adding a chemical crosslinker or curing agent. In other embodiments, the curing step (d-1) further comprises curing the curable green body with UV radiation to form an SSE green body. For example, the curing step may be carried out with UV radiation from a UV lamp. In some embodiments, the UV lamp emits UV light at a wavelength of about 10 nm to about 500 nm (e.g., about 250 nm to about 440 nm).

[0085] In another aspect of the present invention, a green body for forming a solid-state electrolyte (SSE) is provided, the green body comprising an LLZO material and a curable binder, the green body exhibiting an area shrinkage of less than about 60% when sintered.

[0086] In some embodiments, the green body exhibits an areal shrinkage of less than about 55% when sintered. In other embodiments, the green body exhibits an areal shrinkage of less than about 50% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 45% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 40% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 35% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 30% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 25% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 20% when sintered.

[0087] In some embodiments, the LLZO material (e.g., sintered LLZO material) comprises LLZO powder, doped LLZO powder, or any combination thereof. In other embodiments, the LLZO material comprises LLZO powder. Also, in some embodiments, the LLZO material comprises doped LLZO powder.

[0088] In some embodiments, the doped LLZO powder includes a dopant. For example, the dopant can include Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof.

[0089] In some embodiments, the doped LLZO powder has Formula (I): M1 7-x D1 a M2 3-y D2 b M3 2-z D3 c O 12-w D4d (I) The composition comprises: During the ceremony, M1 is Li, M2 is La, M3 is Zr, D1 is Be, B, Al, Fe, Zn, Ga, Ge, or any combination thereof; D2 is Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Zn, Ce, or any combination thereof; D3 is Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Ce, Eu, Te, Y, Sr, Ca, Ba, Gd, Ge, or any combination thereof; and D4 is F, Cl, Br, I, S, Se, Te, N, P, or any combination thereof; however, 0≦w≦2, -0.5 <x≦3、 0≦y≦3, 0≦z≦2, 0≦a≦2, 0≦b≦3, 0≦c≦2, and 0≦d≦2, where at least one of a, b, c, and d is greater than 0.

[0090] In some embodiments, the LLZO material has a D90 particle size of less than about 10 μm, in other embodiments, the LLZO material has a D90 particle size of less than about 5 μm, and in some embodiments, the LLZO material has a D90 particle size of less than about 2.5 μm.

[0091] In some embodiments, the binder is cured by exposure to ultraviolet (UV) radiation. In other embodiments, the cured binder comprises a crosslinked polymeric material.

[0092] In some embodiments, the green body has a thickness of about 500 nm to about 1000 μm. In some embodiments, the green body has a thickness of about 1 μm to about 100 μm. In other embodiments, the green body has a thickness of about 1 μm to about 75 μm. In some embodiments, the green body has a thickness of about 1 μm to about 50 μm. In some embodiments, the green body has a thickness of about 1 μm to about 25 μm. In other embodiments, the green body has a thickness of about 1 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 60 μm.

[0093] In some embodiments, the green body further comprises a first layer and a second layer at least partially disposed on the first layer. In such embodiments, the LLZO material is further defined as a first LLZO material and the binder is further defined as a first binder. The first layer comprises the first LLZO material and the first binder. The second layer comprises the second LLZO material and the second binder.

[0094] In some embodiments, the second layer further comprises a pore-former, hi other embodiments, the first layer is substantially free of a pore-former.

[0095] In some embodiments, the first layer has a thickness of about 500 μm to about 1000 μm. In some embodiments, the second layer has a thickness of about 1 μm to about 10 μm. In some embodiments, the second layer has a thickness of about 10 μm to about 50 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 100 μm. In other embodiments, the first layer has a thickness of about 1 μm to about 75 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 50 μm. In some embodiments, the first layer has a thickness of about 1 μm to about 25 μm.

[0096] In some embodiments, the second layer has a thickness of about 500 μm to about 1000 μm. In some embodiments, the second layer has a thickness of about 1 μm to about 10 μm. In some embodiments, the second layer has a thickness of about 10 μm to about 50 μm. In some embodiments, the second layer has a thickness of about 1 μm to about 100 μm. In other embodiments, the second layer has a thickness of about 1 μm to about 80 μm. In some embodiments, the second layer has a thickness of about 20 μm to about 80 μm. In some embodiments, the second layer has a thickness of about 20 μm to about 60 μm. [Brief explanation of the drawings]

[0097] The following figures are illustrative and do not limit the scope of the claimed invention.

[0098] [Figure 1] 1 is a flowchart of a method for calculating area shrinkage of a green body according to one embodiment of the present invention.

[0099] [Figure 2] 1 is a flow chart of a method of forming a green body according to one embodiment of the present invention.

[0100] [Figure 3] 4 is a flow chart of a method of forming a green body according to another embodiment of the present invention.

[0101] [Figure 4A] 1 shows X-ray powder diffraction (XRPD) patterns of LLZO materials according to Examples 1 and 2.

[0102] [Figure 4B] FIG. 4B is a magnified view of the XRPD pattern of FIG. 4A.

[0103] [Figure 5A] 1 shows X-ray powder diffraction (XRPD) patterns of additional LLZO materials according to Examples 1 and 2.

[0104] [Figure 5B] FIG. 5B is a magnified view of the XRPD of FIG. 5A. DETAILED DESCRIPTION OF THE INVENTION

[0105] The present invention provides a green body for forming a solid electrolyte and a method for forming the same.

[0106] As used herein, the following definitions shall apply unless otherwise stated.

[0107] I. Definition

[0108] The terminology used herein is used only for the purpose of describing particular exemplary configurations and is not intended to be limiting. As used herein, the singular articles "a," "an," and "the" may be intended to include the plural unless the context clearly dictates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically stated as an order of performance. Additional or alternative steps may be employed.

[0109] Terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers, and / or sections. These elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first," "second," and other numerical terms do not imply an order or sequence unless clearly indicated by context. Thus, a first element, component, region, layer, or section described below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the illustrated configuration.

[0110] As used herein, when an element is described as being "on," "engaged to," "connected," "attached," or "coupled" to another element, the element may be directly on, engaged with, connected to, attached to, or coupled to the other element, or there may be intervening elements. Conversely, when an element is described as being "directly abutting," "directly engaged," "directly connected," "directly attached," or "directly coupled" to another element, this means that there are no intervening elements or layers present. Other terms used to describe relationships between elements should be interpreted similarly (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0111] As used herein, the term "green body" refers to an unsintered body (e.g., a tape and / or film) comprising an LLZO material and a binder. In some embodiments, the green body is dry (i.e., the green body is substantially free of all volatile or high vapor pressure solvents (e.g., containing less than 1 wt%, less than 0.75 wt%, less than 0.50 wt%, less than 0.25 wt%, less than 0.1 wt%, less than 0.05 wt%, or less than 0.01 wt%, or no detectable traces, based on the weight of the green body)).

[0112] As used herein, the terms "lithium lanthanum zirconium oxide green body" and "SSE green body" are used interchangeably and refer to a green body (e.g., a tape and / or film) comprising an LLZO material and a binder. In some embodiments, the SSE green body is dry (i.e., the SSE green body is free of all volatile or high vapor pressure solvents).

[0113] As used herein, the term "LLZO material" refers to a material comprising a doped or undoped LLZO cubic garnet phase or a tetragonal garnet phase. In some embodiments, the LLZO material comprises an LLZO powder, a doped LLZO powder, or any combination thereof.

[0114] As used herein, the term "binder" refers to a material that promotes adhesion of another material (e.g., an LLZO material) and is removable from the green body via debinding and / or sintering. In some embodiments, the binder is a curing binder.

[0115] As used herein, the term "cured binder" refers to a material that is at least partially cured and removable from a green body by debinding. In some embodiments, the cured binder is cured (or partially cured) by exposure to ultraviolet (UV) radiation. In some embodiments, the cured binder has a glass transition temperature above room temperature.

[0116] As used herein, the term "area shrinkage" refers to the percent areal shrinkage exhibited by a green body after sintering (i.e., when the green body is sintered to form a sintered body). The percent areal shrinkage is calculated according to the formula (1):

number

[0117] If the sintered body contains microcracks or damage that may distort the area of ​​the sintered body, the area of ​​the sintered body is approximated by the surface dimensions (e.g., length and width) perpendicular to the thickness of the sintered body. In other words, the area of ​​the sintered body is approximated based on the area if the sintered body did not contain any cracks or damage.

[0118] As used herein, the term "area shrinkage" refers to the percent volumetric shrinkage exhibited by a green body after sintering (i.e., when the green body is sintered to form a sintered body). The percent volumetric shrinkage is calculated using Equation (2):

number

[0119] As used herein, the term "theoretical density" refers to the maximum density that a material (e.g., an LLZO material) can achieve if it is assumed that there are no voids (e.g., pores) or impurities inside. Theoretical density is calculated using the following formula (3):

number

[0120] For green bodies (e.g., SSE green bodies), the theoretical density (i.e., ρ グリーンボディ ) is expressed as equation (3-1):

number

[0121] For example, for a two-component green body (e.g., LLZO material and binder), the theoretical density (i.e., ρ グリーンボディ ) is expressed as equation (3-2):

number

[0122] As another example, for a three-component green body (e.g., LLZO material, binder, and pore former), the theoretical density (i.e., ρ グリーンボディ ) is expressed as equation (3-3):

number

[0123] As used herein, the term "density factor" refers to the density factor calculated from equation (4):

number

[0124] Unless otherwise stated herein, all "ρ 測定 " values ​​were measured in accordance with ASTM D 1475-98, ASTM B923-22, or ASTM D792-20, as applicable.

[0125] Unless otherwise stated herein, any "ρ グリーンボディ The value of " was also calculated for a dry green body (i.e., the green body is free of all volatile or high vapor pressure solvents).

[0126] As used herein, the term "characteristic peaks," when referring to peaks in the X-ray powder diffraction (XRPD) pattern of an LLZO material described as an SSE green body, refers to a particular collection of peaks whose 2θ values, spanning the range of 0° to 80°, are uniquely assigned to the LLZO material as a whole.

[0127] As used herein, the term "substantially pure sample of LLZO material" refers to a sample of LLZO material (e.g., LLZO powder or doped LLZO powder) that is substantially free of impurities and / or subphases (e.g., less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, less than about 0.25%, less than about 0.1%, less than about 0.01%, or less than about 0.001%). In some embodiments, a substantially pure sample of LLZO material may refer to a sample of LLZO material immediately after its synthesis (e.g., calcination).

[0128] As used herein, the term "initiator" refers to a chemical that starts a polymerization reaction in the presence of a monomer or a cross-linking reaction in the presence of a polymer.

[0129] As used herein, the term "photoinitiator" refers to a chemical compound that forms reactive species when exposed to radiation (e.g., ultraviolet (UV) radiation or visible radiation). The reactive species formed from the photoinitiator can initiate crosslinking or polymerization.

[0130] As used herein, the term "decomposed photoinitiator" refers to any non-reactive species that results from a photoinitiator after exposure to radiation. A decomposed photoinitiator may be derived from a reactive species that initiated and / or proceeded with polymerization and / or crosslinking and is thereby quenched (i.e., rendered non-reactive). Alternatively, a decomposed photoinitiator may be a stable (i.e., non-reactive) species that forms from a photoinitiator immediately after exposing the photoinitiator to radiation (i.e., without any subsequent or intervening reaction occurring).

[0131] As used herein, the term "protonated LLZO (LiHLSO)" refers to a compound that has a certain amount (x) of protons (i.e., H + ) is substituted for x lithium ions in the LLZO lattice. LiHLZO is a LLZO material in which Li 7-x H x La3Zr2O 12 LiHLZO is a phase impurity that reduces the density of the LLZO material. LiHLZO is a phase impurity that reduces the density of the LLZO material when the LLZO material is in a solvent (e.g., a protic solvent (e.g., water as shown in reaction (A-1) below, an alcohol as shown in reactions (B) and (C) below, or an acid)) or has a pK of less than about 22, less than about 21, less than about 20, or less than about 19. a LiHLZO may be produced by reacting with LLZO material (any solvent having a .alpha., ... [ka]

[0132] In embodiments in which the LLZO material comprises a doped LLZO material, it will be understood that protons replace lithium ions in the doped LLZO material in substantially the same manner.

[0133] As used herein, the term "D90 particle size" refers to the particle size at or below which 90% of the corresponding material particles (e.g., LLZO powder or doped LLZO powder) fall by volume. The D90 particle size can be determined by any suitable particle size analyzer. For example, the D90 particle size can be measured by a Horiba LA-910 particle size analyzer (Horiba Instruments, Irvin, Calif.).

[0134] II. Green Body

[0135] In one aspect, the present invention provides a green body for a solid electrolyte, the green body comprising an LLZO material and a binder.

[0136] A.LLZO material

[0137] In some embodiments, the LLZO material is a lithium perovskite material, LiN, Li-β-alumina, lithium superionic conductor (LISICON), Li 2.88 PO 3.86 N 0.14 (LiPON), sodium superionic conductor (NASICON), Li9AlSiO8, Li 10 GeP2S 12 , a lithium garnet SSE material, a doped lithium garnet SSE material, a lithium garnet composite material, or any combination thereof. In some embodiments, the lithium garnet SSE material is a cation-doped Li5La3M 1 2O 12 (M 1 is Nb, Zr, Ta, or any combination thereof), cation-doped Li6La2BaTa2O 12 , cation-doped Li 7La3 ZrO 12 , and cation-doped Li6BaY2M 1 2O 12 where the cation dopant is barium, yttrium, zinc, or any combination thereof. In another embodiment, the lithium garnet SSE material is Li5La3Nb2O12 , Li5La3Ta2O 12 , Li7La3Zr2O 12 , Li6La2SrNb2O 12 , Li6La2BaNb2O 12 , Li6La2SrTa2O 12 , Li6La2BaTa2O 12 , Li7Y3Zr2O 12 , Li 6.4 Y3Zr 1.4 Ta 0.6 O 12 , Li 6.5 La 2.5 Ba 0.5 TaZrO 12 , Li6BaY2M 1 2O 12 , Li7Y3Zr2O 12 , Li 6.75 BaLa2Nb 1.75 Zn 0.25 O 12 , Li 6.75 BaLa2Ta 1.75 Zn 0.25 O 12 , or any combination thereof.

[0138] In some embodiments, the LLZO material is a sintered material. For example, the LLZO material includes a doped or undoped LLZO material having a cubic garnet phase. In other examples, the LLZO material includes a doped or undoped LLZO material having a tetrahedral phase. In some embodiments, the LLZO material includes an LLZO powder, a doped LLZO powder, or any combination thereof. In other embodiments, the LLZO material includes an LLZO powder. In some embodiments, the LLZO material includes a doped LLZO powder. Also, in some embodiments, the LLZO material includes an LLZO powder and a doped LLZO powder.

[0139] In some embodiments, the LLZO powder is substantially free of dopants (e.g., the LLZO powder includes less than 0.5 wt%, less than 0.25 wt%, less than 0.1 wt%, less than 0.01 wt%, or less than 0.001 wt%, of dopants relative to the weight of the LLZO powder). In other embodiments, the LLZO powder does not include dopants.

[0140] In some embodiments, the doped LLZO powder includes a dopant. For example, the dopant may include Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof. In some embodiments, the dopant includes Be. In other embodiments, the dopant includes B. In some embodiments, the dopant includes Al. In some embodiments, the dopant includes Fe. In some embodiments, the dopant includes Zn. In some embodiments, the dopant includes Ga. In some embodiments, the dopant comprises Ge. In some embodiments, the dopant comprises Na. In some embodiments, the dopant comprises K. In other embodiments, the dopant comprises Ca. In some embodiments, the dopant comprises Rb. In some embodiments, the dopant comprises Sr. In some embodiments, the dopant comprises Y. In some embodiments, the dopant comprises Ag. In some embodiments, the dopant comprises Ba. In some embodiments, the dopant comprises Bi. In some embodiments, the dopant comprises Pr. In some embodiments, the dopant comprises Nd. In some embodiments, the dopant comprises Pm. In some embodiments, the dopant comprises Sm. In some embodiments, the dopant comprises Gd. In some embodiments, the dopant comprises Tb. In some embodiments, the dopant comprises Dy. In some embodiments, the dopant comprises Ho. In some embodiments, the dopant comprises Er. In some embodiments, the dopant comprises Tm. In some embodiments, the dopant comprises Ce. In some embodiments, the dopant comprises Mg. In some embodiments, the dopant comprises Si. In some embodiments, the dopant comprises Sc. In some embodiments, the dopant comprises Ti.In some embodiments, the dopant comprises V. In some embodiments, the dopant comprises Cr. In some embodiments, the dopant comprises Mn. In some embodiments, the dopant comprises Co. In some embodiments, the dopant comprises Ni. In some embodiments, the dopant comprises Cu. In some embodiments, the dopant comprises As. In some embodiments, the dopant comprises Se. In some embodiments, the dopant comprises Nb. In some embodiments, the dopant comprises Mo. In some embodiments, the dopant comprises Tc. In some embodiments, the dopant comprises Ru. In some embodiments, the dopant comprises Rh. In some embodiments, the dopant comprises Pd. In some embodiments, the dopant comprises Cd. In some embodiments, the dopant comprises In. In some embodiments, the dopant comprises Sn. In some embodiments, the dopant comprises Sb. In some embodiments, the dopant comprises Hf. In some embodiments, the dopant comprises Ta. In some embodiments, the dopant comprises W. In some embodiments, the dopant comprises Ir. In some embodiments, the dopant comprises Pt. In some embodiments, the dopant comprises Au. In some embodiments, the dopant comprises Hg. In some embodiments, the dopant comprises Ti. In some embodiments, the dopant comprises Pb. In some embodiments, the dopant comprises Eu. In some embodiments, the dopant comprises Te.

[0141] In some embodiments, the doped LLZO powder has Formula (I): M1 7-x D1 a M2 3-y D2 b M3 2-z D3 c O 12-w D4 d (I) The composition comprises: During the ceremony, M1 is Li, M2 is La, M3 is Zr, D1 is Be, B, Al, Fe, Zn, Ga, Ge, or any combination thereof; D2 is Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Zn, Ce, or any combination thereof; D3 is Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Ce, Eu, Te, Y, Sr, Ca, Ba, Gd, Ge, or any combination thereof; and D4 is F, Cl, Br, I, S, Se, Te, N, P, or any combination thereof; however, 0≦w≦2, -0.5 <x≦3、 0≦y≦3, 0≦z≦2, 0≦a≦2, 0≦b≦3, 0≦c≦2, and 0≦d≦2, where at least one of a, b, c, and d is greater than 0.

[0142] In any formula component herein (e.g., D1, D2, D3 and / or D4), the component may include a combination of atoms, a combination of cations, or a combination of anions, and the subscript (e.g., a, b, c, and / or d) immediately following such component represents the aggregate pfu (per formula unit) of all atoms, anions, and / or cations in the combination (and not the pfu of a specific atom, anion, and / or cation).

[0143] In another embodiment, the doped LLZO powder has the formula (II): Li 7-x D1 a La3-y D2 b Zr 2-z D3 c O 12-w D4 d (II), comprising the composition of wherein D1 is Be, B, Al, Fe, Zn, Ga, Ge, or any combination thereof, D2 is Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Zn, Ce, or any combination thereof, D3 is Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Te, I, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Ce, Eu, Te, Y, Sr, Ca, Ba, Gd, Ge, or any combination thereof, D4 is F, Cl, Br, I, S, Se, Te, or any combination thereof, 0 ≦ w < 2, and in some embodiments, 0 ≦ w ≦ 1, and in some embodiments 0 ≦ w ≦ 0.5, and in some embodiments, 0 ≦ w ≦ 0.1, -0.5 < x ≦ 3, and in some embodiments, 0 < x ≦ 1.5, 0 < yy ≦ 3, in some embodiments, 0 < y ≦ 2, 0 < z ≦ 2, and in some embodiments, 0 < z ≦ 1.5, 0 < a < 1, and in some embodiments, 0 < a < 0.24, 0 < b ≦ 3, and in some embodiments, 0 < b ≦ 2, 0 < c ≦ 2, and in some embodiments, 0 < c ≦ 1.5, 0 ≦ d ≦ 2, and in some embodiments, 0 ≦ d ≦ 1, and in some embodiments, 0 ≦ d ≦ 0.5, and in some embodiments, 0 ≦ d ≦ 0.1.

[0144] In some embodiments of the composition of formula (II), D1 is Al, Ga, or any combination thereof; 0 <a≦0.15であり、 D2 is Ca, Sr, Ba, or any combination thereof, and 0 <b≦0.5であり、 D3 is Ta, Nb, W, Ti, Mo, or any combination thereof, and 0 <c≦1.0であり、 D4 is F, Cl, or any combination thereof, and 0≦d≦0.25; 0≦x≦1.0, 0≦y≦0.5, 0≦z≦1.0, and 0≦w≦0.25.

[0145] Examples of compositions of formula (II) are shown in Table 1.

[0146] [Table 1]

[0147] In another embodiment, the doped LLZO powder has formula (III): Li 7-3x-y+z B x La 3-y C y Zr 2-z D z O 12-a G 2a / n (III), The composition comprises: During the ceremony, B is any trivalent cation (e.g., Al 3+ or Ga 3+ ), or any combination thereof (in some embodiments, the charge can be corrected by removing three Li for one trivalent B); C is a divalent cation (e.g., Mg 2+ ) or any combination thereof, and D is a pentavalent cation (e.g., Nb 5+or any combination thereof, G is any anion, monovalent (e.g., F- ), divalent (e.g., S2- ), or trivalent (e.g., N3- ), or G is absent, and n is the charge of the dopant, 0 < x ≤ 0.5, 0 < y ≤ 3, 0 < z ≤ 2, and 0 ≤ a ≤ 12,

[0148] In some embodiments, B is selected from Al, Ga, H, Fe, Zn, or any combination thereof, C is Ca, Mg, Sr, Ba, Na, Ce, or any combination thereof, D is Ta, Y, Mo, Sb, Nb, W, Ge, Ti, or any combination thereof, G is selected from F, Cl, or any combination thereof, or G is absent. In some embodiments, 0 < x < 0.24, 0.1 < y ≤ 1.5, 0.2 < z ≤ 1, and 0 ≤ a ≤ 0.5.

[0149] In some embodiments, the doped LLZO powder has the formula (IV): Li n B x vB La 3-y C y vC Zr 2-z D z vD O 12-a G a (IV), comprising the composition of, wherein, n = 7 - x(v B ) + y(3 - v C ) + z(4 - v D ) - a / 2; v B is the oxidation state of the dopant B, v Cis the oxidation state of the dopant C, and v D is the oxidation state of the dopant D (in this formula, any changes in vacancies and charges are balanced by the amount of lithium in the formula, but a similar approach can be used by also balancing the amount of oxygen in the formula), B is H + , Al 3+ , or Ga 3+ In some embodiments, B is a cation such as Al 3+ is. C is Ca 2+ , Ba 2+ , Sr 2+ , Mg 2+ , Rb + , Ce 4+ In some embodiments, C is a cation such as Ca 2+ is. D is Ta 5+ , Y 3+ , Mo 6+ , Nb 5+ , W 6+ , Ge 4+ , Ti 4+ In some embodiments, D is a cation such as Ta 5+ , Nb 5+ , Ti 4+ In other embodiments, D is Ta 5+ is. G is not present or F- or Cl- or any combination thereof. For each of the cations listed for B, C, and D, where applicable, different oxidation states of the cation may be used to vary the balance of lithium or oxygen within the system and control the final properties of the solid electrolyte as needed. Further, if the combination of cations is doped at any particular site having the same or different oxidation states, Equation IV may be used with the same terms added to the equation for n. For example, if dopants for Li sites B1 and B2 are desired, the equation for n is n = 7 - x1(v B1 ) - x2(v B2 ) + y(3 - v C ) + z(4 - v D ) - a / 2. Similar modifications can be made for multiple C dopants, D dopants, G dopants, or combinations thereof. 0 < x < 0.24, in some embodiments 0 < x < 0.15, and in other embodiments 0.02 < x < 0.10. 0 < y ≤ 1.0, in some embodiments 0 < y < 0.5, in other embodiments 0.1 < y < 0.30, and in some embodiments 0.15 < y < 0.28. 0 < y ≤ 1.0, in some embodiments 0 < y < 0.7, in other embodiments 0.3 < y < 0.6, and in some embodiments 0.4 < z < 0.55. 0 ≤ a ≤ 1.0, in some embodiments 0 ≤ a ≤ 0.1, and in other embodiments 0 ≤ a < 0.05.

[0150] It should be understood that Equations (III) and (IV) can be used, in particular, as guidance in selecting the compositions of Equations (I) and (II) with respect to the composition of a particular element compared to other elements. The relative compositions are useful in producing a single-phase garnet product.

[0151] In some embodiments, the doped LLZO powder has the formula (V): Li 7-x B a La 3-y C b Zr2-z D c O 12 (V), comprising the composition of wherein B is Al or Ga, C is Ca, Sr, Ba, or Mg, D is Ta, Nb, W, Mo, or Ti, -0.5 < x ≤ 1, 0 < a < 0.24, 0 < y ≤ 0.5, 0 < b ≤ 0.5, 0 < z ≤ 1, and 0 < c ≤ 1, wherein x, a, y, b, z, and c are independent of each other.

[0152] For example, in some embodiments of the composition according to formula (V), 0.2 ≤ x ≤ 0.8, 0 < a ≤ 0.15, 0 < y ≤ 0.3, 0 < b ≤ 0.3, 0 < z ≤ 1, and 0 < c ≤ 1.

[0153] In some embodiments, x is 0.15 to 0.7.

[0154] In some embodiments, B is Al and a is 0.05 to 0.15. For example, x is 0.15 to 0.7, B is Al, and a is 0.05 to 0.15.

[0155] In some embodiments, B is Ga and a is 0.05 to 0.8. For example, x is 0.15 to 0.7, B is Ga, and a is 0.05 to 0.8.

[0156] In some embodiments, y is 0.05 to 0.30. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, and y is 0.05 to 0.30. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, and y is 0.05 to 0.30.

[0157] In some embodiments, C is Ca and b is 0.05 to 0.25. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.25. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.25.

[0158] In some embodiments, C is Ba and b is 0.05 to 0.10. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, and b is 0.05 to 0.10. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, and b is 0.05 to 0.10.

[0159] In some embodiments, C is Sr and b is 0.25 to 0.30. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, and b is 0.25 to 0.30.

[0160] In some embodiments, C is Mg and b is 0.22 to 0.28. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28. In other examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, and b is 0.22 to 0.28.

[0161] In some embodiments, z is 0.50 to 1. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, and z is 0.50 to 1.

[0162] In some embodiments, D is Ta and c is 0.4 to 0.6. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15-0.7, B is Al, a is 0.05-0.15, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15-0.7, B is Ga, a is 0.05-0.8, y is 0.05-0.30, C is Sr, b is 0.25-0.30, z is 0.50-1, D is Ta, and c is 0.4-0.6. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ta, and c is 0.4 to 0.6.

[0163] In some embodiments, D is Nb and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Nb, and c is 0.2 to 0.4.

[0164] In some embodiments, D is Ti and c is 0.8 to 1.0. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is Ti, and c is 0.8 to 1.0.

[0165] In some embodiments, D is W and c is 0.2 to 0.4. For example, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ca, b is 0.05 to 0.25, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Ba, b is 0.05 to 0.10, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Sr, b is 0.25 to 0.30, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Al, a is 0.05 to 0.15, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4. In some examples, x is 0.15 to 0.7, B is Ga, a is 0.05 to 0.8, y is 0.05 to 0.30, C is Mg, b is 0.22 to 0.28, z is 0.50 to 1, D is W, and c is 0.2 to 0.4.

[0166] Examples of compositions of formula (V) are shown in Table 2.

[0167] [Table 2]

[0168] In some embodiments, the LLZO material is substantially in the cubic garnet phase. As used herein, the term "substantially in the cubic phase" refers to an LLZO material that comprises at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of the cubic phase.

[0169] In some embodiments, the LLZO material is substantially in the tetragonal garnet phase. As used herein, the term "substantially in the tetragonal phase" refers to an LLZO material that contains at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of the tetragonal phase.

[0170] In some embodiments, the LLZO material is substantially in the tetragonal and / or cubic garnet phase (i.e., comprises at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of the tetragonal and / or cubic phase). In other words, both the tetragonal and cubic phases may be present in the LLZO material.

[0171] In some embodiments, the LLZO material is substantially free of secondary phases. As used herein, the term "substantially free of secondary phases" refers to an LLZO material that contains less than about 20%, less than about 15%, less than about 10%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or less than about 1% secondary phases. In some embodiments, the solid electrolyte material is free of secondary phases. Exemplary secondary phases include, but are not limited to, LiHLZO (i.e., Li 7-x H x LZO), Li2CO3, LiOH, Li2O, La2Zr2O7, La2O3, ZrO2, Li2ZrO3, Li6Zr2O7, Li8ZrO6, LiAlO2, or any combination thereof.

[0172] In some embodiments, the LLZO material has a D90 particle size of less than about 50 μm. For example, the LLZO material may have a D90 particle size of less than about 25 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 10 μm. In other embodiments, the LLZO material has a D90 particle size of less than about 7.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 2.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 1.5 μm. In other embodiments, the LLZO material has a D90 particle size of less than about 1.0 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 0.5 μm. Also, in some embodiments, the LLZO material has a D90 particle size of less than about 0.3 μm.

[0173] In some embodiments, the LLZO material is present in a range of about 5% to about 80% by volume based on the total volume of the green body, in other embodiments, the LLZO material is present in a range of about 15% to about 70% by volume based on the total volume of the green body, and in some embodiments, the LLZO material is present in a range of about 20% to about 60% by volume based on the total volume of the green body.

[0174] B. Binder

[0175] The binder promotes adhesion of another material (eg, an LLZO material) and is removable from the green body via debinding and / or sintering.

[0176] In some embodiments, the binder is a cured binder. In some embodiments, the cured binder comprises a crosslinked polymer material. The crosslinked polymer material is formed from at least one polymer comprising a crosslinkable moiety, or any combination thereof. For example, the crosslinkable moiety of the at least one polymer can be a vinyl moiety, a carbonyl moiety, a thiocarbonyl moiety, an epoxide moiety, a hydroxyl moiety, or any combination thereof.

[0177] In some embodiments, the crosslinked polymeric material comprises a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, polyisoprene, or any combination thereof. In some embodiments, the crosslinked polymeric material comprises a polysiloxane. In some embodiments, the crosslinked polymeric material comprises a polyurethane. In some embodiments, the polymeric material comprises a polythioester. In some embodiments, the crosslinked polymeric material comprises a polyacrylate. In some embodiments, the crosslinked polymeric material comprises a vinyl polymer. Also, in some embodiments, the crosslinked polymeric material comprises polyisoprene.

[0178] As used herein, the term "vinyl polymer" refers to a polymer derived from vinyl (e.g., substituted vinyl) monomers. Examples of suitable vinyl polymers include polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), polyvinyl acetate (PVAc), polyacrylonitrile, polyvinyl butyral (PVB), or any combination thereof.

[0179] In some embodiments, the cured binder is cured by exposure to radiation. In some embodiments, the cured binder is cured by exposure to ultraviolet (UV) radiation. In other embodiments, the cured binder is cured by heating (i.e., thermal curing). In other embodiments, the binder is cured by the addition of a curing agent or crosslinking agent.

[0180] In some embodiments, the binder is an uncured binder, i.e., the binder is an uncured binder, e.g., the binder comprises a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof, and the binder is not substantially crosslinked.

[0181] In some embodiments, the binder is present in the green body in an amount of about 20% to about 95% by volume, based on the total volume of the green body. In other embodiments, the binder is present in the green body in an amount of about 30% to about 85% by volume, based on the total volume of the green body. In some embodiments, the binder is present in an amount of about 40% to about 80% by volume, based on the total volume of the green body.

[0182] C. Photoinitiator / Decomposed Photoinitiator

[0183] In some embodiments, the green body further comprises a photoinitiator, a decomposed photoinitiator, or any combination thereof. If present, the photoinitiator and / or decomposed photoinitiator can be removed from the green body by debinding and / or sintering.

[0184] The photoinitiator can be any photoinitiator suitable for initiating crosslinking. For example, the photoinitiator can be 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexylphenyl ketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one), 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoate, ethyl 4-(dimethylamino)benzoate, a polymeric photoinitiator thereof, or any combination thereof.In some embodiments, the photoinitiator comprises 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxy-cyclohexyl phenyl ketone, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, polymeric photoinitiators thereof, or any combination thereof. In other embodiments, the photoinitiator comprises benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1 butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl 4-(N,N-dimethylamino)benzoate, ethyl-4-(dimethylamino)benzoate, polymeric photoinitiators thereof, or any combination thereof.

[0185] The decomposed photoinitiator may be any inactive species derived from any of the photoinitiators described herein.

[0186] In some embodiments, the photoinitiator is present in the green body in an amount less than about 3%, less than about 2.5%, less than about 2%, less than about 1%, less than about 0.5%, less than about 0.25%, less than about 0.1%, less than about 0.01%, or less than about 0.001% by weight based on the total weight of the green body.

[0187] In some embodiments, the decomposed initiator is present in the green body in an amount less than about 3%, less than about 2.5%, less than about 2%, less than about 1%, less than about 0.5%, less than about 0.25%, less than about 0.1%, less than about 0.01%, or less than about 0.001% by weight based on the total weight of the green body.

[0188] D. Optional Solvent / Dispersant(s)

[0189] In some embodiments, the green body optionally includes a solvent. The solvent may be used to facilitate processing and / or handling during formation of the green body. If present, the solvent can be removed from the green body by debinding and / or sintering.

[0190] In some embodiments, the solvent is substantially non-reactive with the LLZO material. As used herein, the term "substantially non-reactive with the LLZO material" refers to a solvent that is aprotic or otherwise non-reactive with the LLZO material. For example, the solvent may be substantially non-reactive with the LLZO material, such that LiHLZO is not formed or only a limited amount of LiHLZO is formed after exposure to the solvent (i.e., the LLZO material contains less than about 20%, less than about 10%, less than about 7.5%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or less than about 1% of LiHLZO after exposure to the solvent).

[0191] In some embodiments, the solvent does not include water, ethanol, isopropanol, methanol, terpiol, acetic acid, or formic acid.

[0192] In some embodiments, the solvent has a pK of at least about 12, at least about 13, at least about 14, at least about 15, at least about 16, at least about 17, at least about 18, at least about 19, at least about 20, at least about 21, or at least about 22. a It has.

[0193] In some embodiments, the solvent comprises an aprotic solvent (e.g., a polar aprotic solvent or a non-polar aprotic solvent). The aprotic solvent may be substantially non-reactive with the LLZO material. For example, the aprotic solvent may comprise acetone, acetonitrile, dichloromethane, diisopropylamine, triethylamine, dimethyl sulfoxide, dimethyl sulfone, ethyl acetate, pyridine, tetrahydrofuran, pentane, hexane, diethyl ether, benzene, toluene, or any combination thereof.

[0194] In some embodiments, the solvent comprises less than about 2%, less than about 1%, less than about 0.5%, less than about 0.25%, less than about 0.1%, less than about 0.01%, or less than about 0.001% by weight based on the total weight of the green body.

[0195] In some embodiments, the green body optionally comprises a dispersant. Dispersants useful in the green bodies of the present invention are substantially inert in the presence of the LLZO material and / or binder. In other examples, the green body (cured and / or uncured) and / or binder mixture comprises a dispersant, the dispersant comprising fish oil, a fatty acid ester, a sulfonated fatty acid, or any combination thereof.

[0196] In some embodiments, the green body comprises less than 10 wt% (e.g., less than 5 wt%, less than 3 wt%, less than 1 wt%, or less than 0.5 wt%) of a dispersant by weight of the green body. In some embodiments, the dispersant has a pH greater than about 8.

[0197] E. Pore formers

[0198] In some embodiments, the green body further comprises a pore former. If present, the pore former is removable by debinding and / or sintering and promotes the formation of pores in the sintered body. The pore former can be any material suitable for forming pores during debinding and / or sintering.

[0199] For example, the pore-forming agent may include a polymer, carbon spheres, carbon tubes, starch, or any combination thereof. In some embodiments, the pore-forming agent includes a polymer. For example, the polymer may include polypropylene, polyethylene, polymethylpentene, polybutene-1, ethylene-octene copolymer, propylene-butane copolymer, polyisobutylene, poly(α-olefin), ethylene propylene rubber, ethylene propylene diene monomer rubber, ethylene vinyl acetate, ethylene-acrylate copolymer, polyamide, polyester, polyurethane, styrene block copolymer, polycaprolactone, polyimide, polyvinyl chloride, polycarbonate, polyacrylate, polymethacrylate, fluoropolymer, epoxy resin, epoxy polymer, silicone rubber, styrenes, acrylonitrile butadiene styrene (ABS), or any combination thereof.

[0200] In some embodiments, the pore former comprises carbon spheres, in some embodiments, the pore former comprises carbon tubes, and in some embodiments, the pore former comprises starch.

[0201] In some embodiments, the pore former is present in an amount of about 0% to about 80% by volume based on the total volume of the green body. In other embodiments, the pore former is present in an amount of about 10% to about 70% by volume based on the total volume of the green body. In some embodiments, the pore former is present in an amount of about 15% to about 60% by volume based on the total volume of the green body.

[0202] In some embodiments, the green body has a thickness of about 500 nm to about 1000 μm. In some embodiments, the green body has a thickness of about 1 μm to about 100 μm. In other embodiments, the green body has a thickness of about 1 μm to about 75 μm. In some embodiments, the green body has a thickness of about 1 μm to about 50 μm. In some embodiments, the green body has a thickness of about 1 μm to about 25 μm. In other embodiments, the green body has a thickness of about 1 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 80 μm. In some embodiments, the green body has a thickness of about 20 μm to about 60 μm. In some embodiments, the green body has a thickness of about 100 μm to about 200 μm. In some embodiments, the green body has a thickness of about 150 μm to about 300 μm. In some embodiments, the green body has a thickness of about 250 μm to about 500 μm. In some embodiments, the green body has a thickness of about 350 μm to about 500 μm. In some embodiments, the green body has a thickness of about 500 μm to about 750 μm. In some embodiments, the green body has a thickness of about 750 μm to about 1000 μm.

[0203] F. Two-layer green body

[0204] In some embodiments, the green body further comprises a first layer and a second layer at least partially disposed on the first layer. In such embodiments, the LLZO material is further defined as a first LLZO material and the binder is further defined as a first binder. The first layer comprises the first LLZO material and the first binder. The second layer comprises the second LLZO material and the second binder.

[0205] The first LLZO material can be any LLZO material described herein. The second LLZO material can be any LLZO material described herein. In some embodiments, the first and second LLZO materials are the same. In other embodiments, the first and second LLZO materials are different.

[0206] The first binder can be any binder described herein. The second binder can be any binder described herein. In some embodiments, the first and second binders are the same. In other embodiments, the first and second binders are different.

[0207] In some embodiments, the second layer further comprises a pore-forming agent. The pore-forming agent can be any pore-forming agent described herein. For example, the pore-forming agent can include a polymer, carbon spheres, carbon tubes, starch, or any combination thereof.

[0208] In some embodiments, the first layer is substantially free of pore-formers (e.g., the first layer comprises less than about 10%, less than about 5%, less than about 2.5%, less than about 1%, less than about 0.1%, less than about 0.01%, or less than about 0.001% pore-former by weight of the first layer). In other embodiments, the first layer does not comprise a pore-former.

[0209] G. Density rate

[0210] In some embodiments, the green body has a percent density of at least about 87.5%. In other embodiments, the green body has a percent density of at least about 90%. In some embodiments, the green body has a percent density of at least about 92.5%. In some embodiments, the green body has a percent density of at least about 95%. In some embodiments, the green body has a percent density of at least about 96%. In some embodiments, the green body has a percent density of at least about 97%. In other embodiments, the green body has a percent density of at least about 97.5%. In some embodiments, the green body has a percent density of at least about 98%. In some embodiments, the green body has a percent density of at least about 98.5%. In some embodiments, the green body has a percent density of at least about 99%. In some embodiments, the green body has a percent density of at least about 99.5%.

[0211] Without wishing to be bound by theory, it is believed that the green bodies described herein (e.g., SSE green bodies) have reduced impurities and / or secondary phases (e.g., LiHLZO content) compared to conventional green bodies. These reduced impurities and / or secondary phases (e.g., LiHLZO content) result in green bodies having higher percent densities compared to conventional green bodies. Furthermore, this increased density advantageously promotes greater control and predictability over sintered products (e.g., SSE separator layers, bilayers, etc.) due to the reduced amount of shrinkage associated with higher density.

[0212] H. Contraction

[0213] In some embodiments, the green body exhibits an areal shrinkage of less than about 60% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 57.5% when sintered. In other embodiments, the green body exhibits an areal shrinkage of less than about 55% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 52.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 50% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 47.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 45% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 42.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 40% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 37.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 35% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 32.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 30% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 27.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 25% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 22.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 20% when sintered.

[0214] In some embodiments, the green body exhibits an areal shrinkage of less than about 70% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 67.5% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 65% when sintered. In some embodiments, the green body exhibits an areal shrinkage of less than about 62.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 60% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 57.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 55% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 52.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 50% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 47.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 45% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 42.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 40% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 37.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 35% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 32.5% when sintered. In some embodiments, the green body exhibits a volumetric shrinkage of less than about 30% when sintered.

[0215] Without wishing to be bound by theory, it is believed that the green bodies described herein (e.g., SSE green bodies) have reduced impurities and / or secondary phases (e.g., LiHLZO content) compared to conventional green bodies. Because higher impurities and / or secondary phases (e.g., LiHLZO content) are accompanied by greater mass loss and density change, these reduced impurities and / or secondary phases (e.g., LiHLSO content) result in area and / or volume shrinkage compared to conventional green bodies (assuming the same debinding and sintering conditions). Furthermore, reduced area and / or volume shrinkage advantageously allows for greater control and predictability of the sintered product (e.g., SSE separator layer, bilayer, etc.), including its uniformity and dimensions.

[0216] I. XRPD Pattern

[0217] In some embodiments, the LLZO material in a green body (e.g., an SSE green body) has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks in a sample of the substantially pure LLZO material. In other embodiments, the LLZO material in a green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±0.90 degrees of the corresponding peaks in a sample of the substantially pure LLZO material. In some embodiments, the LLZO material in a green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±0.80 degrees of the corresponding peaks in a sample of the substantially pure LLZO material. In some embodiments, the LLZO material in a green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±0.70 degrees of the corresponding peaks in a sample of the substantially pure LLZO material. In other embodiments, the LLZO material in a green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±0.60 degrees of the corresponding peaks in a sample of the substantially pure LLZO material, and in some embodiments, the LLZO material in a green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±0.50 degrees of the corresponding peaks in a sample of the substantially pure LLZO material.

[0218] In some embodiments, the substantially pure sample of LLZO material is a sample of LLZO material immediately after its synthesis (e.g., calcination).

[0219] Without wishing to be bound by theory, it is believed that the green bodies described herein (e.g., SSE green bodies) have reduced impurities and / or secondary phases (e.g., LiHLZO content) compared to conventional green bodies. These reduced impurities and / or secondary phases (e.g., LiHLZO content) result in an XRPD pattern of the LLZO material of the green body in which one or more characteristic peaks are within a narrower threshold (e.g., ±1.00 degrees, ±0.90 degrees, ±0.80 degrees, ±0.70 degrees, ±0.60 degrees, or ±0.50 degrees) of the corresponding peak of a sample of substantially pure LLZO material compared to conventional green bodies. In other words, due to the reduced impurities and / or secondary phases, the green body exhibits an XRPD pattern that more closely resembles the XRPD pattern of pure LLZO material compared to conventional green bodies.

[0220] In another aspect, the present invention provides a green body for forming a solid electrolyte, the green body comprising an LLZO material and a binder, the green body exhibiting an area shrinkage of less than about 60% when sintered.

[0221] In one aspect, the present invention provides an SSE green body for forming a solid electrolyte, the SSE green body comprising an LLZO material and a curable binder, the SSE green body exhibiting an area shrinkage of less than about 60% when sintered.

[0222] In a further aspect, the present invention provides a green body for forming a solid electrolyte, the green body comprising an LLZO material and a binder, the LLZO material of the green body having an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of corresponding peaks of a sample of substantially pure LLZO material.

[0223] In one aspect, the present invention provides an SSE green body for forming a solid electrolyte, the SSE green body comprising an LLZO material and a curing binder, wherein the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of corresponding peaks of a sample of substantially pure LLZO material.

[0224] In one aspect, the present invention provides a green body for forming a solid electrolyte, the green body comprising an LLZO material and a binder, the green body having a density of at least about 87.5%.

[0225] In one aspect, the present invention provides an SSE green body for forming a solid electrolyte, the SSE green body comprising an LLZO material and a curing binder, the SSE green body having a density of at least about 87.5%.

[0226] In yet another aspect, the present invention provides a green body for forming a solid electrolyte. The green body further comprises an LLZO material, a binder, and a photoinitiator, a decomposed photoinitiator, or any combination thereof. In some embodiments, the green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a sample of substantially pure LLZO material. Also, in some embodiments, the green body has a density of at least about 87.5%.

[0227] In yet another aspect, the present invention provides an SSE green body for forming a solid electrolyte. The green body further comprises an LLZO material, a curable binder, and a photoinitiator, a decomposed photoinitiator, or any combination thereof. In some embodiments, the SSE green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a sample of substantially pure LLZO material. Also, in some embodiments, the SSE green body has a density fraction of at least about 87.5%.

[0228] III. Method for forming a green body

[0229] Another aspect of the present invention provides a method for forming a green body for a solid electrolyte. Referring to Figure 2, a flow chart illustrating an exemplary embodiment for forming a green body for a solid electrolyte is provided. The method includes: (a) reacting a precursor mixture to form an LLZO material (202); (b) mixing the LLZO material with a binder composition to form a binder mixture (204); (c) forming a green body from the binder mixture (206).

[0230] The LLZO material can be any LLZO material described herein. In some embodiments, reacting step (a) further comprises reacting the precursor mixture by calcining to form the LLZO material. For example, the calcination may be carried out at a temperature of about 700°C to about 1,100°C. In other embodiments, the calcination is carried out at a temperature of about 800°C to about 1,000°C. In some embodiments, the calcination is carried out at a temperature of about 850°C to about 950°C.

[0231] In other embodiments and examples, reacting step (a) further comprises reacting the precursor mixture by a sol-gel process. In some embodiments, reacting step (a) further comprises reacting the precursor mixture by co-precipitation.

[0232] In some embodiments, the method further comprises: (d) dry-milling the LLZO material to form a milled LLZO material.

[0233] In some embodiments, the dry-milling step (d) is performed before the mixing step (b). In some embodiments, the dry-milling step (b) further comprises: (d1) mixing the LLZO material with a grinding additive; (d2) dry-milling the LLZO material to form a milled LLZO material.

[0234] In some embodiments, the grinding additive comprises a starch, a fatty acid, a fatty acid salt, an active polymeric dispersant, or any combination thereof. For example, the grinding additive can comprise a starch. In some embodiments, the starch comprises corn starch, potato starch, tapioca starch, arrowroot starch, wheat starch, potato starch, or any combination thereof.

[0235] In some embodiments and examples, the grinding additive comprises a fatty acid, for example, α-linolenic acid, stearidonic acid, eicosapentaenoic acid, cervonic acid, linoleic acid, linolelaidic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid, docosatetraenoic acid, palmitoleic acid, vaccenic acid, paulinic acid, oleic acid, elaidic acid, gondoic acid, erucic acid, nervonic acid, mead acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, or the like. The grinding additive may comprise a fatty acid salt, such as pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, he)icosylic acid, behenic acid, tricosylic acid, lignoceric acid, pentacosylic acid, cerotic acid, carboseric acid, montanic acid, nonacosylic acid, melissic acid, hentriacontylic acid, lacceroic acid, psyllic acid, geddic acid, ceroplastic acid, hexatriacontylic acid, heptatriacontylic acid, octatriacontylic acid, nonatriacontylic acid, tetracontylic acid, or any combination thereof. In some embodiments, the grinding additive comprises a fatty acid salt. For example, the fatty acid salts can include lithium fatty acid salts, sodium fatty acid salts, potassium fatty acid salts, ammonium fatty acid salts, or any combination thereof.

[0236] In some embodiments, step (d1) is performed before step (d2). In other embodiments, step (d1) is performed simultaneously with step (d2). Also, in some embodiments, the method further comprises: (d3) After step (d2), removing the grinding additive from the ground LLZO material.

[0237] In some embodiments, the dry-milling step (d) is carried out in a jet mill or an attrition mill. For example, the dry-milling step (d) is carried out in a jet mill. In other embodiments, the dry-milling step (d) is carried out in an attrition mill.

[0238] In some embodiments, the LLZO material has a D90 particle size of less than about 50 μm. For example, the LLZO material may have a D90 particle size of less than about 25 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 10 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 7.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 5 μm. Also, in some embodiments, the LLZO material has a D90 particle size of less than about 2.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 1.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 1.0 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 0.5 μm. Also, in some embodiments, the LLZO material has a D90 particle size of less than about 0.3 μm.

[0239] In some embodiments, the binder composition comprises a binder. In some embodiments, the binder is a crosslinkable polymeric material. For example, the crosslinkable polymeric material can include at least one monomer comprising a crosslinkable moiety, at least one oligomer comprising a crosslinkable moiety, at least one polymer comprising a crosslinkable moiety, or any combination thereof. For example, the crosslinkable moiety of the at least one monomer, the at least one oligomer, and / or the at least one polymer can be a vinyl moiety, a carbonyl moiety, a thiocarbonyl moiety, an epoxide moiety, a hydroxyl moiety, an acrylate moiety, or any combination thereof. In some embodiments, the crosslinkable moiety is a vinyl moiety. In other embodiments, the crosslinkable moiety is a carbonyl moiety. In some embodiments, the crosslinkable moiety is a thiocarbonyl moiety. In some embodiments, the crosslinkable moiety is an epoxide moiety. In some embodiments, the crosslinkable moiety is a hydroxyl moiety. Also, in some embodiments, the crosslinkable moiety is an acrylate moiety.

[0240] In some embodiments, the at least one monomer, at least one oligomer, and / or at least one polymer comprises a polyurethane, a polythioester, an acrylate, a polyacrylate, a vinyl polymer, a polyisoprene, an epoxy polymer, a monomer thereof, an oligomer thereof, or any combination thereof.

[0241] In some embodiments, the binder composition further comprises a photoinitiator. The photoinitiator can be any photoinitiator described herein. For example, photoinitiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexyl phenyl ketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one), 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl) The photoinitiator may include (2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoate, ethyl 4-(dimethylamino)benzoate, a polymeric photoinitiator thereof, or any combination thereof.

[0242] In some embodiments, the binder composition includes a solvent. The solvent can be any solvent described herein. In some embodiments, the solvent is substantially non-reactive with the LLZO material. In some embodiments, the binder composition has a pK of at least about 12, at least about 13, at least about 14, at least about 15, at least about 16, at least about 17, at least about 18, at least about 19, at least about 20, at least about 21, or at least about 22. a In other embodiments, the solvent comprises an aprotic solvent (e.g., a polar aprotic solvent or a non-polar aprotic solvent). The aprotic solvent may be substantially non-reactive with the LLZO material. For example, the aprotic solvent may comprise acetone, acetonitrile, dichloromethane, diisopropylamine, triethylamine, dimethyl sulfoxide, dimethyl sulfone, ethyl acetate, pyridine, tetrahydrofuran, pentane, hexane, diethyl ether, benzene, toluene, or any combination thereof.

[0243] In some embodiments, the binder composition further comprises a dispersant, a plasticizer, or any combination thereof.

[0244] The mixing step (b) may be carried out, for example, in a mixer. In some embodiments, the mixing step (b) further comprises: (b1) mixing an LLZO material with a binder composition to form a curable SSE mixture; (b2) removing agglomerates from the binder mixture.

[0245] In some embodiments, if the binder composition includes a solvent, the forming step (c) further comprises removing the solvent from the binder composition to form a green body. In other embodiments, the curing step (c) further comprises forming a green body from the binder mixture by spray deposition, fused deposition modeling, screen printing, high shear compression, or any combination thereof.

[0246] In some embodiments, step (c) further comprises: (c1) forming a curable green body from the binder mixture; (c2) curing the curable green body to form an SSE green body.

[0247] In some embodiments, the forming step (c1) includes forming a curable green body from the binder mixture by casting (e.g., tape casting). For example, the curable green body may be formed by casting the binder mixture onto a substrate. Exemplary substrates include, but are not limited to, Mylar, silicone-coated Mylar, metal foil (such as Ni, Al, Cu, Ti), polyethylene terephthalate (PET), Kapton, polyethylene, polyethylene oxide, or any combination thereof. In some embodiments, the casting is performed using a doctor blade.

[0248] In some embodiments, curing step (c2) comprises curing the curable green body with ultraviolet (UV) radiation, heat (i.e., heat curing), electron beam (e-beam) radiation, or any combination thereof. For example, curing step (c2) may comprise curing the curable green body with UV radiation. In other embodiments, curing step (c2) comprises curing the curable green body with heat. In some embodiments, curing step (c2) comprises curing the curable green body with electron beam radiation. In other embodiments, curing step (c2) comprises adding a chemical crosslinker or curing agent.

[0249] In some embodiments, the curing step (c2) further includes curing the curable green body by UV radiation from a UV lamp to form a green body. In some embodiments, the UV lamp emits UV light at a wavelength of about 10 nm to about 500 nm. In some embodiments, the UV lamp emits light at a wavelength of about 250 nm to about 445 nm. In some embodiments, the UV lamp emits light at a wavelength of about 300 nm to about 445 nm. In some embodiments, the UV lamp emits UV light at a wavelength of about 315 nm to about 400 nm, about 280 nm to about 314 nm, or about 100 to 279 nm. In other embodiments, the UV lamp emits UV light at a wavelength of about 300 nm to about 400 nm, about 200 nm to about 299 nm, about 122 to about 200 nm, or about 10 nm to about 121 nm.

[0250] In some embodiments, the curing step (c2) takes about 0.1 seconds to about 1 hour. In other embodiments, the curing step (c2) takes about 0.1 seconds to about 30 minutes. Also, in some embodiments, the curing step (c2) takes about 0.1 seconds to about 1 minute.

[0251] Another aspect of the present invention provides a method for forming a green body for a solid electrolyte. Referring to FIG. 3, a flowchart showing an exemplary embodiment of forming a green body for a solid electrolyte is provided. The method includes (a-1) reacting a precursor mixture to form an LLZO material, wherein the precursor mixture includes (i) a lithium-containing compound, (ii) a lanthanum-containing compound, and (iii) a zirconium-containing compound (302), (b-1) mixing the LLZO material with a binder composition (e.g., a curable binder composition) to form a curable binder mixture (304), (c-1) forming a curable green body from the binder mixture (306), (d-1) curing the curable green body to form an SSE green body (308).

[0252] In some embodiments, the lithium-containing compound includes lithium metal, an oxide of lithium, a hydroxide of lithium, a halide salt of lithium, a carbonate salt of lithium, a nitrate salt of lithium, or any combination thereof. For example, the lithium-containing compound can be Li2O, LiOH, LiOH·H2O, LiCl, Li2CO3, LiNO3, or any combination thereof. In some embodiments, the lithium-containing compound includes LiO2. In some embodiments, the lithium-containing compound includes LiOH. In other embodiments, the lithium-containing compound includes LiOH·H2O. In some embodiments, the lithium-containing compound includes LiCl. In some embodiments, the lithium-containing compound includes Li2CO3. In some embodiments, the lithium-containing compound includes LiNO3.

[0253] In some embodiments, the lanthanum-containing compound includes lanthanum metal, lanthanum oxide, lanthanum hydroxide, lanthanum halide salt, lanthanum carbonate, lanthanum nitrate, or any combination thereof. For example, the lanthanum-containing compound can be La2O3, La(OH)3, LaCl3, La2(CO3)3, La(NO3)3, or any combination thereof. In some embodiments, the lanthanum-containing compound includes La2O3. In some embodiments, the lanthanum-containing compound includes La(OH)3. In other embodiments, the lanthanum-containing compound includes LaCl3. In some embodiments, the lanthanum-containing compound includes La2(CO3)3. Also, in some embodiments, the lanthanum-containing compound includes La(NO3)3.

[0254] In some embodiments, the zirconium-containing compound includes zirconium metal, zirconium oxide, zirconium hydroxide, zirconium halide, zirconium carbonate, zirconium nitrate, or any combination thereof. For example, the zirconium-containing compound can be ZrO2, Zr(OH)4, ZrCl4, Zr(OH)2CO3·ZrO2, Zr(NO3)4, or any combination thereof. In some embodiments, the zirconium-containing compound includes ZrO2. In some embodiments, the zirconium-containing compound includes Zr(OH)4. In some embodiments, the lithium-containing compound includes LiO4. In some embodiments, the zirconium-containing compound includes Zr(OH)2CO3·ZrO2. Also, in some embodiments, the zirconium-containing compound includes Zr(NO3)4.

[0255] In some embodiments, the precursor further comprises (iv) a dopant, for example, Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, oxides thereof, hydroxides thereof, halogen salts thereof, carbonates thereof, nitrates thereof, or any combination thereof.

[0256] The LLZO material can be any LLZO material described herein.

[0257] In some embodiments, the reacting step (a-1) further comprises reacting the precursor mixture by calcination to form the LLZO material. For example, the calcination may be carried out at a temperature of about 700°C to about 1,100°C. In other embodiments, the calcination is carried out at a temperature of about 800°C to about 1,000°C. In some embodiments, the calcination is carried out at a temperature of about 850°C to about 950°C.

[0258] In other embodiments and examples, the reacting step (a-1) further comprises reacting the precursor mixture by a sol-gel process. In some embodiments, the reacting step (a-1) further comprises reacting the precursor mixture by co-precipitation.

[0259] In some embodiments, the method further (or optionally) comprises: (e-1) dry-milling the LLZO material to form a pulverized LLZO material.

[0260] In some embodiments, the dry-milling step (e-1) is carried out before the mixing step (b-1). In some embodiments, the dry-milling step (e-1) further comprises: (e1-1) mixing the LLZO material with a grinding additive; (e2-1) dry-milling the LLZO material to form a pulverized LLZO material.

[0261] In some embodiments, the dry-milling step (e-1) further comprises: (e2-1a) dry-milling an LLZO material without using a grinding additive to form a ground LLZO material.

[0262] An additional method for forming a pure-phase milled LLZO material includes wet milling in a non-reactive medium (e.g., a non-reactive liquid milling medium), with or without grinding additives. Another method for forming a pure-phase milled LLZO material includes wet milling in a reactive solvent, with or without grinding additives, followed by further processing of the powder to remove phase impurities while maintaining the desired particle size. In some cases, the further processing includes heat treatment under a suitable gas atmosphere.

[0263] In some embodiments, the grinding additive comprises a starch, a fatty acid, a fatty acid salt, an active polymeric dispersant, or any combination thereof. For example, the grinding additive can comprise a starch. In some embodiments, the starch comprises corn starch, potato starch, tapioca starch, arrowroot starch, wheat starch, potato starch, or any combination thereof.

[0264] In some embodiments and examples, the grinding additive comprises a fatty acid, for example, α-linolenic acid, stearidonic acid, eicosapentaenoic acid, cervonic acid, linoleic acid, linolelaidic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid, docosatetraenoic acid, palmitoleic acid, vaccenic acid, paulinic acid, oleic acid, elaidic acid, gondoic acid, erucic acid, nervonic acid, mead acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, or the like. The grinding additive may comprise a fatty acid salt, such as pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, he)icosylic acid, behenic acid, tricosylic acid, lignoceric acid, pentacosylic acid, cerotic acid, carboseric acid, montanic acid, nonacosylic acid, melissic acid, hentriacontylic acid, lacceroic acid, psyllic acid, geddic acid, ceroplastic acid, hexatriacontylic acid, heptatriacontylic acid, octatriacontylic acid, nonatriacontylic acid, tetracontylic acid, or any combination thereof. In some embodiments, the grinding additive comprises a fatty acid salt. For example, the fatty acid salts can include lithium fatty acid salts, sodium fatty acid salts, potassium fatty acid salts, ammonium fatty acid salts, or any combination thereof.

[0265] In some embodiments, the grinding in step (e1-1) includes a grinding additive, wherein the grinding additive is one or more fatty acids, and the grinding additive is provided at about 5 wt% or less (e.g., 4 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 5 wt% or less, about 4 wt% or less, about 3 wt% or less, about 2 wt% or less, or about 1 wt%) relative to the weight of the LLZO material.

[0266] In some embodiments, step (e1-1) is performed before step (e2-1). In other embodiments, step (e1-1) is performed simultaneously with step (e2-1). Also, in some embodiments, the method further comprises: (e3-1) After step (e2-1), removing the grinding additive from the ground LLZO material.

[0267] In some embodiments, the dry-milling step (e-1) is carried out in a jet mill or an attrition mill. For example, the dry-milling step (e-1) is carried out in a jet mill. In some embodiments, the dry-milling step (e-1) is carried out in an attrition mill.

[0268] In some embodiments, the LLZO material has a D90 particle size of less than about 50 μm. For example, the LLZO material may have a D90 particle size of less than about 25 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 10 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 7.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 5 μm. Also, in some embodiments, the LLZO material has a D90 particle size of less than about 2.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 1.5 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 1.0 μm. In some embodiments, the LLZO material has a D90 particle size of less than about 0.5 μm. Also, in some embodiments, the LLZO material has a D90 particle size of less than about 0.3 μm.

[0269] In some embodiments, the curable binder composition comprises (i) at least one monomer, at least one oligomer, or at least one polymer, and (ii) at least one of an initiator and a dispersant, wherein the binder composition forms a crosslinked polymeric material. In some examples, the curable binder composition comprises (i) at least one monomer, at least one oligomer, or at least one polymer, and (ii) an initiator (e.g., a photoinitiator). In some examples, the curable binder composition comprises (i) at least one monomer, at least one oligomer, or at least one polymer, (ii) an initiator (e.g., a photoinitiator), and (iii) a dispersant.

[0270] In some embodiments, the curable binder comprises a crosslinkable polymeric material. For example, the crosslinkable polymeric material can comprise at least one monomer comprising a crosslinkable moiety, at least one oligomer comprising a crosslinkable moiety, at least one polymer comprising a crosslinkable moiety, or any combination thereof. For example, the crosslinkable moiety of the at least one monomer, the at least one oligomer, and / or the at least one polymer can be a vinyl moiety, a carbonyl moiety, a thiocarbonyl moiety, an epoxide moiety, a hydroxyl moiety, an acrylate moiety, or any combination thereof. In some embodiments, the crosslinkable moiety is a vinyl moiety. In other embodiments, the crosslinkable moiety is a carbonyl moiety. In some embodiments, the crosslinkable moiety is a thiocarbonyl moiety. In some embodiments, the crosslinkable moiety is an epoxide moiety. In some embodiments, the crosslinkable moiety is a hydroxyl moiety. Also, in some embodiments, the crosslinkable moiety is an acrylate moiety.

[0271] In some embodiments, the at least one monomer, at least one oligomer, and / or at least one polymer comprises a polyurethane, a polythioester, an acrylate, a polyacrylate, a vinyl polymer, a polyisoprene, an epoxy polymer, a monomer thereof, an oligomer thereof, or any combination thereof.

[0272] In some embodiments, the curable binder composition further comprises a photoinitiator. The photoinitiator can be any photoinitiator described herein. For example, photoinitiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexyl phenyl ketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one), 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl) The photoinitiator may include (2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoate, ethyl 4-(dimethylamino)benzoate, a polymeric photoinitiator thereof, or any combination thereof.

[0273] For example, the curable binder composition may include, by way of non-limiting example, Loctite AA3462, Loctite AA344, Loctite AA352, and / or Loctite AA3951, all of which are commercially available from Henkel Corporation.

[0274] In some examples and embodiments, the curable binder composition comprises UV-Curable Adhesive LC-3200, commercially available from 3M (St. Paul, Minn.).

[0275] In other examples, the curable binder composition comprises Permabond UV610, UV620, UV625, UV630, UV632, UV639, UV640, UV645, UV670, UV681, UV683, UV6160, UV6231, and / or UV7141, all of which are commercially available from Permabond Engineering Adhesives.

[0276] In some embodiments, the curable binder composition further comprises a solvent. The solvent can be any solvent described herein. In some embodiments, the solvent is substantially non-reactive with the LLZO material. In some embodiments, the solvent has a pK of at least about 12, at least about 13, at least about 14, at least about 15, at least about 16, at least about 17, at least about 18, at least about 19, at least about 20, at least about 21, or at least about 22. a In other embodiments, the solvent comprises an aprotic solvent (e.g., a polar aprotic solvent or a non-polar aprotic solvent). The aprotic solvent may be substantially non-reactive with the LLZO material. For example, the aprotic solvent may comprise acetone, acetonitrile, dichloromethane, diisopropylamine, triethylamine, dimethyl sulfoxide, dimethyl sulfone, ethyl acetate, pyridine, tetrahydrofuran, pentane, hexane, diethyl ether, benzene, toluene, or any combination thereof.

[0277] In some embodiments, the binder composition further comprises a dispersant, a plasticizer, or any combination thereof.

[0278] The mixing step (b-1) may be carried out, for example, in a stirrer. In some embodiments, the mixing step (b-1) further comprises: (b1-1) mixing an LLZO material with a curable binder composition to form a curable SSE mixture; (b2-1) removing agglomerates from the curable SSE mixture.

[0279] In some embodiments, the mixing step (b-1) further comprises: (b3-1) Degassing the curable SSE mixture.

[0280] In some embodiments, the forming step (c-1) includes forming a curable green body from the curable SSE mixture by casting the curable SSE mixture. For example, the curable green body may be formed by casting the curable SSE mixture onto a substrate. Exemplary substrates include, but are not limited to, Mylar, silicone-coated Mylar, metal foil (such as Ni, Al, Cu, or Ti), PET, Kapton, polyethylene, polyethylene oxide, or any combination thereof. In some embodiments, the casting is performed using a doctor blade.

[0281] In some embodiments, the curing step (d-1) further comprises curing the curable green body with UV radiation, heat (i.e., thermal curing), electron beam radiation, or any combination thereof to form the SSE green body. For example, the curing step (d-1) may comprise curing the curable green body with UV radiation. In other embodiments, the curing step (d-1) comprises curing the curable green body with heat. In some embodiments, the curing step (d-1) comprises curing the curable green body with electron beam radiation. In still other embodiments, the curing step (d-1) comprises adding a chemical crosslinker or curing agent.

[0282] In some embodiments and examples, the curing step may be performed by UV radiation from a UV lamp. In some embodiments, the UV lamp emits UV light at a wavelength of about 10 nm to about 500 nm. In some embodiments, the UV lamp emits light at a wavelength of about 250 nm to about 445 nm. In some embodiments, the UV lamp emits light at a wavelength of about 300 nm to about 445 nm. In some embodiments, the UV lamp emits UV light at a wavelength of about 315 nm to about 400 nm, about 280 nm to about 314 nm, or about 100 to 279 nm. In other embodiments, the UV lamp emits UV light at a wavelength of about 300 nm to about 400 nm, about 200 nm to about 299 nm, about 122 nm to about 200 nm, or about 10 nm to about 121 nm.

[0283] In some embodiments, the curing step (d-1) takes from about 0.1 seconds to about 1 hour. In other embodiments, the curing step (d-1) takes from about 0.1 seconds to about 30 minutes. In some embodiments, the curing step (d-1) takes from about 0.1 seconds to about 1 minute.

[0284] In some embodiments, the method further comprises repeating steps (c-1) and (d-1) to form a bilayer SSE green body. In such embodiments, the second layer is at least partially disposed on the first layer of the SSE green body. In such embodiments, the curable SSE mixture of the second layer may further comprise a pore former. The pore former may be any pore former described herein.

[0285] In another aspect, the present invention provides a method of forming an SSE green body for a solid electrolyte, the method comprising: (a-2) reacting a precursor mixture to form an LLZO material, wherein: (i) lithium-containing compounds, (ii) lanthanum-containing compounds, and (iii) forming a zirconium-containing compound; (b-2) dry-milling the LLZO material to form a pulverized LLZO material; (c-2) mixing the ground LLZO material with an ultraviolet (UV) curable binder composition to form a UV curable mixture; (d-2) forming a UV-curable green body from the UV-curable mixture; (e-2) curing the UV curable green body to form an SSE green body.

[0286] In another aspect, the present invention provides a method for forming a green body for a solid electrolyte, the method comprising: (a-3) providing an LLZO material; (b-3) mixing the LLZO material with a binder composition to form a binder mixture; (c-3) forming a green body from the binder mixture.

[0287] In another aspect, the present invention provides a method of forming an SSE green body for a solid electrolyte, the method comprising: (a-4) providing an LLZO material; (b-4) mixing the LLZO material with a binder composition (e.g., a curable binder composition) to form a curable SSE mixture; (c-4) forming a curable green body from the curable SSE mixture; and (d-4) curing the curable green body to form an SSE green body.

[0288] In another aspect, the present invention provides a method of forming an SSE green body for a solid electrolyte, the method comprising: (a-5) providing an LLZO material; (b-5) dry-milling the LLZO material to form a pulverized LLZO material; (c-5) mixing the ground LLZO material with an ultraviolet (UV) curable binder composition to form a UV curable mixture; (d-5) forming a UV-curable green body from the UV-curable mixture; (e-5) curing the UV curable green body to form an SSE green body.

[0289] Another aspect of the present invention provides a green body for a solid electrolyte, the green body being prepared according to any of the methods described herein. In some embodiments, the green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a sample of the substantially pure LLZO material. Also, in some embodiments, the green body has a density of at least about 87.5%.

[0290] A further aspect of the present invention provides an SSE green body for a solid electrolyte, the SSE green body being prepared according to a method comprising: (a-1) reacting a precursor mixture to form an LLZO material, wherein: (i) lithium-containing compounds, (ii) lanthanum-containing compounds, and (iii) forming a zirconium-containing compound; (b-1) mixing an LLZO material with an ultraviolet (UV) curable binder composition to form a UV curable mixture; (c-1) forming a UV-curable green body from the UV-curable mixture; (d-1) curing the UV curable green body to form an SSE green body.

[0291] In some embodiments, the SSE green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a sample of the substantially pure LLZO material. Also, in some embodiments, the SSE green body has a percent density of at least about 87.5%.

[0292] In a further aspect, there is provided an SSE green body for a solid electrolyte, the SSE green body being prepared according to a method comprising: (a-2) reacting a precursor mixture to form an LLZO material, wherein: (i) lithium-containing compounds, (ii) lanthanum-containing compounds, and (iii) forming a zirconium-containing compound; (b-2) dry-milling the LLZO material to form a pulverized LLZO material; (c-2) mixing the ground LLZO material with an ultraviolet (UV) curable binder composition to form a UV curable mixture; (d-2) forming a UV-curable green body from the UV-curable mixture; (e-2) curing the UV curable green body to form an SSE green body.

[0293] In some embodiments, the SSE green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a sample of the substantially pure LLZO material. The LLZO material of the green body has an X-ray powder diffraction pattern characterized by one or more peaks within ±1.00 degrees of the 2θ values ​​of the corresponding peaks of a sample of the substantially pure LLZO material. Also, in some embodiments, the SSE green body has a density of at least about 87.5%.

[0294] A further aspect of the present invention provides an SSE green body for a solid electrolyte, the SSE green body being prepared according to a method comprising: (a-4) providing an LLZO material; (b-4) mixing the LLZO material with a binder composition (e.g., a curable binder composition) to form a curable SSE mixture; (c-4) forming a curable green body from the curable SSE mixture; and (d-4) curing the curable green body to form an SSE green body.

[0295] In some embodiments, the SSE green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a substantially pure sample of the LLZO material. The LLZO material of the green body has an X-ray powder diffraction pattern characterized by one or more peaks within ±1.00 degrees of the 2θ values ​​of the corresponding peaks of a substantially pure sample of the LLZO material. Also, in some embodiments, the SSE green body has a density of at least about 87.5%.

[0296] Another aspect of the present invention provides an SSE green body for a solid electrolyte, the SSE green body being prepared according to a method comprising: (a-5) providing an LLZO material; (b-5) dry-milling the LLZO material to form a pulverized LLZO material; (c-5) mixing the ground LLZO material with an ultraviolet (UV) curable binder composition to form a UV curable mixture; (d-5) forming a UV-curable green body from the UV-curable mixture; (e-5) curing the UV curable green body to form an SSE green body.

[0297] In some embodiments, the SSE green body exhibits an area shrinkage of less than about 60% when sintered. In other embodiments, the LLZO material of the SSE green body has an X-ray powder diffraction pattern characterized by one or more peaks corresponding to 2θ values ​​measured in degrees within ±1.00 degrees of the corresponding peaks of a substantially pure sample of the LLZO material. The LLZO material of the green body has an X-ray powder diffraction pattern characterized by one or more peaks within ±1.00 degrees of the 2θ values ​​of the corresponding peaks of a substantially pure sample of the LLZO material. Also, in some embodiments, the SSE green body has a density of at least about 87.5%. [Example]

[0298] VI. Working Examples

[0299] In order that the invention described herein may be more fully understood, the following examples are set forth. The examples described in this application are provided to illustrate the methods and green bodies provided herein and should not be construed as limiting the scope thereof in any way.

[0300] Example 1: SSE Green Body

[0301] Milling. The doped LLZO powder (260 g) was placed in an attrition mill with zirconia grinding media (Inframat Corporation, Manchester, CT; 2.5 kg) and a grinding additive (stearic acid, Sigma Aldrich, St. Louis, MO; 3 g) to improve flowability. After milling, the milled LLZO powder was sieved to remove the zirconia grinding media.

[0302] Casting and Curing. The ground LLZO powder was mixed with a curable binder composition (Miltec UV curable binder composition commercially available from Miltec UV, Stevensille, Maryland) and dispersed under high shear to remove agglomerates and form a UV-curable mixture. The UV-curable mixture was degassed and then cast using a doctor blade onto a Mylar substrate (silicone-coated MYLAR®-07″ from Tape Casting Warehouse) to form a UV-curable green body. Casting was performed using a TecMasterCoater from Faustel Inc., Germantown, Wisconsin. The UV-curable green body was cured with UV radiation from a UV lamp (MPI-400, Miltec UV, Stevensille, Maryland) to form the SSE green body.

[0303] Example 2: Comparative SS Green Body

[0304] Milling. The doped LLZO powder (200 g) was placed in a bottle with zirconia grinding media and sufficient isopropanol (200 g) to form a fluid mixture. The bottle was then placed in a twin-screw mill for wet milling. The resulting wet-milled mixture was sieved to remove the zirconia grinding media and dried to remove the isopropanol.

[0305] Casting and Drying. After drying, the resulting wet-milled LLZO powder was dispersed in isopropanol and toluene solvents (Menheden fish oil was the dispersant). Polyvinyl butyral (PVB) binder, benzyl butyl phthalate, and polyalkylene glycol plasticizer were mixed into the dispersion until a uniform slurry was formed. The slurry was degassed and then cast onto a Mylar substrate (silicone-coated MYLAR®-07″ from Tape Casting Warehouse) using a doctor blade. The cast tape was then dried in an oven (30°C-50°C) to remove the solvent and form a comparative SSE green body.

[0306] 4A shows the XRPD patterns of the milled LLZO powder prepared according to Example 1, the wet-milled powder according to Example 2, and the calcined LLZO powder according to Example 1 (i.e., the reference powder). The corresponding samples were analyzed with a Bruker D4. As described above, the reference powder of Example 1 was used to prepare the wet-milled powder of Example 2. As shown in FIG. 4B, the wet-milled powder of Example 2 is further shifted relative to the reference powder compared to the milled powder of Example 1. In other words, the milled LLZO powder of Example 1 shows an XRPD (X-ray diffraction) pattern closer to that of the reference powder compared to the wet-milled LLZO powder of Example 2.

[0307] The shift observed in the wet-milled powder of Example 2 is due to the presence of impurities (e.g., LiHLZO) resulting from the use of a solvent (i.e., isopropanol) in the wet-milling process of Example 2. In comparison, the milling process of Example 1 did not require a solvent and resulted in a milled powder with fewer impurities than the wet-milled powder of Example 2.

[0308] Referring to FIG. 5A, XRPD patterns are shown for the SSE green body prepared according to Example 1, the SSE green body prepared according to Example 2, and the calcined LLZO powder prepared according to Example 1 (i.e., the reference powder). Corresponding samples were analyzed using a Bruker D4. As described above, the reference powder of Example 1 was used to prepare the SSE green body of Example 1 and the SSE green body of Example 2. As shown in FIG. 5B, the XRPD pattern of the SSE green body of Example 2 is further shifted relative to the reference powder compared to the XRPD pattern of the SSE green body of Example 1. Wet-milled powders were prepared. In other words, the SSE green body of Example 1 exhibits an XRPD pattern closer to that of the reference powder compared to the SSE green body of Example 2.

[0309] The shift observed in the SSE green body of Example 2 is due to the presence of impurities (e.g., LiHLZO) resulting from the use of a solvent (i.e., isopropanol) in both the wet-milling step and the casting step of Example 2. In comparison, the milling, casting, and curing process of Example 1 did not require a solvent and resulted in an SSE green body with fewer impurities than the SSE green body of Example 2.

[0310] The XRPD patterns demonstrate that performing certain processing steps can result in LLZO green bodies with fewer impurities.

[0311] The percent density of the materials formed in Examples 1 and 2 is shown in Table 3. For the percent density shown in Table 3, the measured density of each SSE green body was calculated according to ASTM B923-22.

[0312] [Table 3]

[0313] The LLZO green body prepared according to Example 1 exhibited a higher density rate than the corresponding LLZO green body prepared according to Example 2. The results demonstrate that the LLZO green body prepared according to Example 1 contains fewer impurities (e.g., LiHLZO) compared to the LLZO green body prepared according to Example 2.

[0314] Example 3: Sintered body

[0315] The LLZO green bodies prepared according to Examples 1 and 2 were cut to the desired size and placed in an oven with a flow of oxygen gas. After cutting, the LLZO green body prepared according to Example 1 had dimensions of 1 cm, 1 cm, and 50 μm. The LLZO green body prepared according to Example 2 had dimensions of 1 cm, 1 cm, and 50 μm. The oxygen gas was present during debinding to completely oxidize and volatilize any organic materials present in the LLZO green body (e.g., binder, decomposed photoinitiator, solvent, etc.). The oven was heated from room temperature (RT) to 640°C at a rate of 0.67°C / min (min). The oven temperature was maintained at 640°C for approximately 60 minutes. The oven was then heated to 1,100°C at a rate of 3°C / min. The oven temperature was maintained at 1,100°C for 5 hours, and then the oven was cooled to 100°C at a rate of 5°C / min. The sintered bodies were removed and analyzed.

[0316] The SSE green body prepared according to Example 1 exhibited an areal shrinkage of 44% and a volume shrinkage of 58%, while the SSE green body prepared according to Example 2 exhibited an areal shrinkage of 60% and a volume shrinkage of 75%. These values ​​further demonstrate that the LLZO green body prepared according to Example 1 has fewer impurities than the LLZO green body prepared according to Example 2 at the same solids loading.

[0317] Equivalents and Scope In the claims, articles such as "a," "an," and "the" can mean one or more unless indicated to the contrary or the context clearly indicates otherwise. A claim or description including "or" between one or more members of a group is considered to be satisfied if one, more than one, or all of the members of the group are present in, employed in, or otherwise relevant to a given product or process, unless indicated to the contrary or the context clearly indicates otherwise. The invention includes embodiments in which exactly one member of a group is present in, employed in, or otherwise relevant to a given product or process. The invention includes embodiments in which more than one, or all of the members of a group are present in, employed in, or otherwise relevant to a given product or process.

[0318] Furthermore, the present invention encompasses all variations, combinations, and substitutions in which one or more limitations, elements, clauses, and descriptive terms from one or more of the enumerated claims are introduced into another claim. For example, any claim that depends on another claim can be modified to include one or more limitations found in any other claim that depends on the same base claim. Where elements are presented as a list, e.g., in Markush group format, each subgroup of elements is also disclosed, and any element(s) may be removed from this group. Of course, when the invention, or aspects of the invention, are generally referred to as comprising certain elements and / or features, a particular embodiment of the invention or aspect of the invention consists of or consists essentially of such elements and / or features. For brevity, these embodiments have not been specifically described verbatim herein. It should also be noted that the terms "comprising" and "containing" are intended to be open-ended, allowing for the inclusion of additional elements or steps. Where ranges are given, endpoints are included. Furthermore, unless otherwise indicated or clearly meant otherwise from the context and the understanding of one of ordinary skill in the art, values ​​expressed as ranges can be considered to be any specific value or subrange within the stated ranges of different embodiments of the invention, down to one-tenth of the unit of the lower limit of the range, unless clearly meant otherwise by the context.

[0319] This application references certain issued patents, published patent applications, journal articles, and other publications, all of which are incorporated herein by reference. In the event of a conflict between any of the incorporated references and this application, the present specification shall control. Moreover, any particular embodiment of the present invention within the prior art may be expressly excluded from any one or more of the claims. Such embodiments may be excluded even if the exclusion is not expressly set forth herein because they are deemed known to those of ordinary skill in the art. Any particular embodiment of the present invention may be excluded from any claim for any reason, whether related to the existence of prior art or not.

[0320] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. The scope of the present embodiments described in this invention is not intended to be limited to the above specification, but rather is as set forth in the appended claims. Those skilled in the art will appreciate that various changes and modifications can be made to this specification without departing from the spirit or scope of the invention, as defined in the following claims.

Claims

1. 1. A green body for forming a solid state electrolyte (SSE), the green body comprising: LLZO materials, and Including binder, The green body has a density percentage of at least about 87.5%.

2. 10. The green body of claim 1, wherein the green body has a density percentage of at least about 90%.

3. 3. The green body of claim 1, wherein the green body has a density of at least about 92.5%.

4. The green body of any one of claims 1 to 3, wherein the green body has a density of at least about 95%.

5. The green body of any one of claims 1 to 4, wherein the green body has a density of at least about 97.5%.

6. The green body of any one of claims 1 to 5, wherein the LLZO material comprises LLZO powder, doped LLZO powder, or any combination thereof.

7. The green body of claim 6 , wherein the LLZO material comprises LLZO powder.

8. The green body of claim 6 , wherein the LLZO material comprises a doped LLZO powder.

9. 9. The green body of claim 8, wherein the doped LLZO powder comprises a dopant, the dopant comprising Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof.

10. The doped LLZO powder has the formula (I): M11 ７－ｘ D16 ａ M2 ３－ｙ D22 ｂ M3 ２－ｚ D3 ｃ O １２－ｗ D4 ｄ (I) The composition comprises: During the ceremony, M1 is Li; M2 is La; M3 is Zr; D1 is Be, B, Al, Fe, Zn, Ga, Ge, or any combination thereof; D2 is Na, K, Ca, Rb, Sr, Y, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Zn, Ce, or any combination thereof; D3 is Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Ge, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Ce, Eu, Te, Y, Sr, Ca, Ba, Gd, Ge, or any combination thereof; and D4 is F, Cl, Br, I, S, Se, Te, N, P, or any combination thereof; however, 0≦w≦2, −0.5<x≦3, 0≦y≦3, 0≦z≦2, 0≦a≦2, 0≦b≦3, 0≦c≦2, and 0≦d≦2, 10. The green body of claim 8 or 9, wherein at least one of a, b, c, and d is greater than 0.

11. The green body of any one of claims 5 to 10, wherein the LLZO material has a D90 grain size of less than about 10 μm.

12. The green body of any one of claims 5 to 11, wherein the LLZO material has a D90 grain size of less than about 5 μm.

13. The green body of any one of claims 5 to 12, wherein the LLZO material has a D90 grain size of less than about 2.5 μm.

14. The green body of any one of claims 5 to 13, wherein the binder is cured by exposure to ultraviolet (UV) radiation.

15. The green body of any one of claims 1 to 14, wherein the binder comprises a cross-linkable polymeric material.

16. The green body of any one of claims 1 to 15, wherein the green body has a thickness of about 500 nm to about 1000 μm.

17. The LLZO material is further defined as a first LLZO material, the binder is further defined as a first binder, and the green body further comprises: a first layer comprising the first LLZO material and the first binder; and The green body of any one of claims 1 to 15, comprising a second layer disposed at least partially on the first layer, the second layer comprising a second LLZO material and a second binder.

18. 20. The green body of claim 17, wherein the second layer further comprises a pore former.

19. 19. The green body of claim 17 or 18, wherein the first layer is substantially free of pore formers.

20. The green body of any one of claims 17 to 19, wherein the first layer has a thickness of about 500 nm to about 1000 μm.

21. The green body of any one of claims 17 to 20, wherein the second layer has a thickness of about 500 μm to about 1000 μm.

22. 22. The green body of any one of claims 17 to 21, wherein the green body is substantially free of any LiHZO impurity.

23. 1. A sintered SSE material, comprising: (i) less than about 10 wt. % LiHLZO, based on the weight of the sintered SSE material; (ii) greater than 90 wt % of formula (V) based on the weight of the sintered SSE material Li ７－ｘ B ａ La ３－ｙ C ｂ Z ２－ｚ D ｃ O １２ (V) doped LLZO material of During the ceremony, B is Al or Ga, C is Ca, Sr, Ba, or Mg; D is Ta, Nb, W, Mo, or Ti; −0.5<x≦1, 0<a<0.24, 0<y≦0.5, 0<b≦0.5, 0<z≦1, and 0<c≦1, wherein x, a, y, b, z, and c are independent of each other.

24. 0.2≦x≦0.8, 0<a≦0.15, 0<y≦0.3, 0<b≦0.3, 0<z≦1, and 24. The sintered SSEE material of claim 23, wherein 0<c≦1.

25. 25. The sintered SSE material of claim 23 or 24, wherein x is 0.15 to 0.

7.

26. 26. The sintered SSE material of any one of claims 23 to 25, wherein B is Al and a is 0.05 to 0.

15.

27. 26. The sintered SSE material of any one of claims 23 to 25, wherein B is Ga and a is 0.05 to 0.

8.

28. 28. The sintered SSE material of any one of claims 23 to 27, wherein y is 0.05 to 0.

30.

29. 29. The sintered SSE material of any one of claims 23 to 28, wherein C is Ca and b is 0.05 to 0.

25.

30. 29. The sintered SSE material of any one of claims 23 to 28, wherein C is Ba and b is 0.05 to 0.

10.

31. 29. The sintered SSE material of any one of claims 23 to 28, wherein C is Sr and b is 0.25 to 0.

30.

32. 29. The sintered SSE material of any one of claims 23 to 28, wherein C is Mg and b is 0.22 to 0.

28.

33. 33. The sintered SSE material of any one of claims 23 to 32, wherein z is 0.50 to 1.

34. 34. The sintered SSE material of any one of claims 23 to 33, wherein D is Ta and c is 0.4 to 0.

6.

35. 34. The sintered SSE material of any one of claims 23 to 33, wherein D is Nb and c is 0.2 to 0.

4.

36. 34. The sintered SSE material of any one of claims 23 to 33, wherein D is Ti and c is 0.8 to 1.

0.

37. 34. The sintered SSE material of any one of claims 23 to 33, wherein D is W and c is 0.2 to 0.

4.

38. 38. The sintered SSE material of any one of claims 23 to 37, comprising a dense layer and a porous layer, the dense layer having a density rate that is at least about 1.5% higher than the density rate of the porous layer.

39. 39. The sintered SSE material of claim 38, wherein the dense layer has a density rate that is at least about 2% higher than the density rate of the porous layer.

40. 40. The sintered material of claim 38 or claim 39, wherein the dense layer or the porous layer has a thickness of about 500 nm to about 1000 μm.

41. 1. A green body for forming a solid state electrolyte (SSE), the green body comprising: an LLZO material comprising less than about 10 wt % LiHLZO based on the weight of the LLZO material; Including binder, The green body comprises about 30% to about 60% binder by volume of the green body.

42. The LLZO material has formula (V): Li ７－ｘ B ａ La ３－ｙ C ｂ Z ２－ｚ D ｃ O １２ (V), The composition comprises: During the ceremony, B is Al or Ga, C is Ca, Sr, Ba, or Mg; D is Ta, Nb, W, Mo, or Ti; −0.5<x≦1, 0<a<0.24, 0<y≦0.5, 0<b≦0.5, 0<z≦1, and 42. The green body of claim 41, wherein 0<z≦1, and wherein x, a, y, b, z, and c are independent of each other.

43. 43. The green body of claim 42, wherein x is between 0.15 and 0.

7.

44. 44. The green body of claim 42 or claim 43, wherein B is Al and a is 0.05 to 0.

15.

45. 44. The green body of claim 42 or claim 43, wherein B is Ga and a is 0.05 to 0.

8.

46. 46. ​​The green body of any one of claims 42 to 45, wherein y is 0.05 to 0.

30.

47. 47. The green body of any one of claims 42 to 46, wherein C is Ca and b is 0.05 to 0.

25.

48. 47. The green body of any one of claims 42 to 46, wherein C is Ba and b is 0.05 to 0.

10.

49. 47. The green body of any one of claims 42 to 46, wherein C is Sr and b is 0.25 to 0.

30.

50. 47. The green body of any one of claims 42 to 46, wherein C is Mg and b is 0.22 to 0.

28.

51. 51. The green body of any one of claims 42 to 50, wherein z is from 0.50 to 1.

52. 52. The green body of claim 42, wherein D is Ta and c is 0.4 to 0.

6.

53. 52. The green body of any one of claims 42 to 51, wherein D is Nb and c is 0.2 to 0.

4.

54. 52. The green body of any one of claims 42 to 51, wherein D is Ti and c is 0.8 to 1.

0.

55. 52. The green body of any one of claims 42 to 51, wherein D is W and c is 0.2 to 0.

4.

56. The green body of any one of claims 42 to 55, wherein the LLZO material is fired.

57. 57. The green body of claim 56, wherein at least about 90% of the LLZO material has a cubic phase.

58. 57. The green body of claim 56, wherein at least about 90% of the LLZO material has a tetragonal phase.

59. 59. The green body of any one of claims 41 to 58, wherein the binder comprises a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof.

60. 60. The green body of any one of claims 41 to 59, further comprising an initiator or a dispersant.

61. The initiator may further comprise 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropane, 1-hydroxy-cyclohexyl phenyl ketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone, 2-ethylhexyl-4-(N,N-dimethylamino)benzoic acid ester, ethyl 4-(dimethylamino)benzoate, or any combination thereof.

62. 62. The green body of claims 41-61, further comprising a dispersant, wherein the dispersant comprises fish oil, a fatty acid ester, a sulfonated fatty acid, or any combination thereof.

63. 63. The green body of any one of claims 41 to 62, wherein the LLZO material comprises less than about 5 wt% LiHLZO, based on a weight of the LLZO material.

64. 64. The green body of any one of claims 41 to 63, further comprising a dense layer and a porous layer, the dense layer having a density rate that is at least 1% higher than the density rate of the porous layer.

65. 65. The green body of claim 64, wherein the porous layer is disposed over at least a portion of the dense layer.

66. 66. The green body of claim 64 or claim 65, wherein the porous layer further comprises a pore former and the dense layer is substantially free of any pore former.

67. 1. A method of forming a green body for a solid electrolyte, the method comprising: (a-1) reacting a precursor mixture to form an LLZO material, the precursor mixture comprising: (i) a lithium-containing compound; (ii) a lanthanum-containing compound, and (iii) forming a zirconium-containing compound; (b-1) mixing the LLZO material with a binder composition to form a curable SSE mixture; (c-1) forming a curable green body from the curable SSE mixture; (d-1) curing the curable green body to form the SSE green body.

68. 68. The method of claim 67, wherein the precursor mixture further comprises a dopant, wherein the dopant comprises Be, B, Al, Fe, Zn, Ga, Ge, Na, K, Ca, Rb, Sr, Ag, Ba, Bi, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Ce, Mg, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, As, Se, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, Hf, Ta, W, Ir, Pt, Au, Hg, Tl, Pb, Eu, Te, or any combination thereof.

69. The lithium-containing compound is Li ２ O, LiOH, LiOH・H ２ O, LiCl, Li ２ CO ３ , LiNO ３ 69. The method of claim 67 or 68, comprising:

70. The lanthanum-containing compound is La ２ O ３ , La(OH) ３ , LaCl ３ , La ２ (CO ３ ) ３ , La(NO ３ ) ３ or any combination thereof.

71. The zirconium-containing compound is ZrO ２ , Zr(OH) ４ , ZrCl ４ , Zr(OH) ２ CO ３ ZrO ２ , Zr(NO ３ ) ４ or any combination thereof.

72. 72. The method of any one of claims 69 to 71, wherein the reacting step (a-1) further comprises reacting by calcining the precursor mixture to form the LLZO material.

73. 73. The method of claim 72, wherein the calcination is carried out at a temperature of from about 700°C to about 1,100°C.

74. moreover, 74. The method of any one of claims 67 to 73, comprising: (e-1) dry-milling the LLZO material to form a milled LLZO material.

75. 75. The method of claim 74, wherein the dry-grinding step (e-1) is carried out before the mixing step (b-1).

76. The dry grinding step (e-1) further comprises: (e1-1) mixing the LLZO material with a grinding additive; The method of claim 74 or claim 75, comprising: (e2-1) dry-milling the LLZO material to form a milled LLZO material.

77. 77. The method of claim 76, wherein the grinding additive comprises a starch, a fatty acid, a fatty acid salt, an active polymeric dispersant, or any combination thereof.

78. 78. The method of claim 76 or claim 77, wherein the grinding additive comprises a starch, the starch comprising corn starch, potato starch, tapioca starch, arrowroot starch, wheat starch, potato starch, or any combination thereof.

79. The grinding additive comprises a fatty acid, and the fatty acid is selected from the group consisting of α-linolenic acid, stearidonic acid, eicosapentaenoic acid, cervonic acid, linoleic acid, linolelaidic acid, γ-linolenic acid, dihomo-γ-linolenic acid, arachidonic acid, docosatetraenoic acid, palmitoleic acid, vaccenic acid, paulic acid, oleic acid, elaidic acid, gondoic acid, erucic acid, nervonic acid, mead acid, propionic acid, butyric acid, valeric acid, caproic acid, and enanthic acid. Caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, hecosylic acid, behenic acid, tricosylic acid, lignoceric acid, pentacosylic acid, cerotic acid, carboceric acid, montanic acid, nonacosylic acid, melissic acid, hentriacontylic acid 78. The method of claim 76 or claim 77, wherein the hydroxybenzoates include hydroxybenzoates selected from the group consisting of hydroxybenzoates, ...

80. 78. The method of claim 76 or claim 77, wherein the grinding additive comprises a fatty acid salt, and the fatty acid salt comprises a lithium fatty acid salt, a sodium fatty acid salt, a potassium fatty acid salt, an ammonium fatty acid salt, or any combination thereof.

81. The method of any one of claims 76 to 80, wherein step (e1-1) is carried out before step (e2-1).

82. 82. The method according to any one of claims 76 to 81, wherein step (e1-1) is carried out simultaneously with step (e2-1).

83. 83. The method of any one of claims 74 to 82, wherein the dry-grinding step (e-1) is carried out using a jet mill or an attrition mill.

84. 84. The method of any one of claims 74 to 83, wherein the ground LLZO material has a D90 particle size of less than about 10 μm.

85. 85. The method of any one of claims 74 to 84, wherein the ground LLZO material has a D90 particle size of less than about 5 μm.

86. 86. The method of any one of claims 74 to 85, wherein the LLZO material has a D90 particle size of less than about 2.5 μm.

87. The method of any one of claims 67 to 86, wherein the binder composition comprises a binder and an initiator.

88. 88. The method of claim 87, wherein the binder comprises a polysiloxane, a polyurethane, a polythioester, a polyacrylate, a vinyl polymer, a polyisoprene, or any combination thereof.

89. The initiator comprises a photoinitiator, and the photoinitiator is selected from the group consisting of 2,2-dimethoxy-1,2-diphenylethan-1-one, maleimide, 2-hydroxy-2-methyl-1-phenylpropane, 1-hydroxy-cyclohexyl phenyl ketone, oligo(2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4-phenylbenzophenone, bis[4-(dimethylamino)phenyl]methanone, methylbenzophenone, 4,4′-bis(diethylamino)benzophenone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, hydroxyacetophenone, isopropylthioxanthone, 2,4,5-trimethylbenzoyl-diphenylphosphine 88. The method of claim 87, comprising a sphingotropic compound comprising a sphingotropic compound selected from the group consisting of sphingotropic compounds, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzil dimethyl ketal, camphorquinone, 2-hydroxy-2-methyl-1-(4-t-butyl)phenylpropan-1-one, bis(2,4,6-trimethylbenzoyl), 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-mercaptobenzoxazole, 2-methyl-1-[4-(methylthiophenyl)-2-morpholinepropanone], 2-ethylhexyl-4-(N,N-dimethylamino)benzoic acid ester, ethyl 4-(dimethylamino)benzoate, or any combination thereof.

90. 90. The method of any one of claims 67 to 89, wherein the forming step (c-1) further comprises casting a layer of the curable SSE mixture onto a substrate, wherein the dense layer has a thickness of from about 750 nm to about 1000 μm.

91. 90. The method of any one of claims 67 to 89, wherein the curing step (d-1) further comprises curing the curable green body with ultraviolet (UV) radiation, heat, electron beam (e-beam) radiation, or any combination thereof to form the SSE green body.

92. 92. The method of claim 89 or claim 91, wherein the curing step (d-1) further comprises curing the curable green body with UV radiation to form the SSE green body.

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