Patent Description:
Solid-state lithium batteries, by enabling lithium metal anode, are expected to provide higher energy densities and faster recharging times and cause less safety concerns compared to conventional lithium-ion batteries. Current solid electrolyte materials include oxides, halides, sulfides, fluorides, and solid polymer electrolytes.

Oxide based materials have been considered safe and possessing good chemical and electrochemical stability. The synthesis of these compounds generally uses high temperatures that are above <NUM>-<NUM>. The oxide based materials are typically dense, rigid, and brittle with ionic conductivity up to <NUM>/cm at room temperature (ICRT).

Halide compounds, such as chlorides and bromides, are generally safe and have good chemical and electrochemical stability, deformability and plasticity, allowing relatively high compatibility with active electrode materials. Some Li<NUM>YCl<NUM> (LYC) and Li<NUM>YBr<NUM> (LYB) electrolytes have demonstrated room temperature ionic conductivity ICRT above <NUM>/cm. Halides are generally hygroscopic and form hydrates or undergo hydrolysis upon exposure to moisture. Halide solid electrolytes, such as LYC and LYB, are synthesized by using high energy ball milling based solid-state synthesis methods. The synthesis possesses challenges for mass production applications, further because expensive binary halide reactants and/or high temperature annealing are used.

Fluorides are very similar to oxides in physical, chemical, and electrochemical properties, but in general have ICRT values below <NUM>/cm.

Sulfides have relatively high ionic conductivity. For instance, ICRT can be as high as <NUM>/cm while commercially relevant sulfide or thiophosphate solid electrolytes can achieve <NUM>-<NUM>/cm. Sulfides materials are mechanically softer and deformable. However, sulfides materials tend to have poor electrochemical stability and cause safety concerns due to the risk of releasing toxic H<NUM>S gas when accidentally reacting together with water and heat. Further, high surface area sulfide solid electrolyte powders pose a particularly high H<NUM>S risk due to their increased reactivity even with ambient humidity.

Solid polymer electrolytes containing lithium salts in general have relatively low ICRT values and electrochemical stability. <NPL> describes a solid electrolyte material [Li<NUM>(NH<NUM>)<NUM>]<NUM>TeCl<NUM>.

The industry continues to demand improved solid electrolyte materials.

Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures can be exaggerated relative to other elements to help improve understanding of embodiments of the invention.

The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but can include other features not expressly listed or inherent to such process, method, article, or apparatus.

The use of "a" or "an" is employed to describe elements and components described herein. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

The materials, methods, and examples are illustrative only and not intended to be limiting.

Embodiments herein relate to a solid electrolyte material including an ammonium-containing complex metal halide as defined in the claims. The metal can include at least one alkali metal element. The solid electrolyte material can have improved bulk ion conductivity. In embodiments, the solid electrolyte material can be used to form a solid state electrolyte, an anode, and/or a cathode. In particular embodiments, the solid electrolyte material can be a suitable component of a solid-state battery. A more particular example of the solid-state battery can include a solid-state lithium battery.

Embodiments relate to methods of forming the solid electrolyte material. The method can allow massive production of the solid electrolyte material in a cost efficient manner.

In an embodiment, the solid electrolyte material includes an ammonium-containing complex metal halide represented by (NH<NUM>)nM<NUM>-z(Mek+)fXn+<NUM>-z+k*f, wherein <NUM><n<<NUM>; <NUM>≤z<<NUM>; <NUM>≤k<<NUM>; <NUM>≤f≤<NUM>; M can include an alkali metal element including Li; X includes a halogen; and Me comprises a rare earth element, Zr, Hf, Ti, Sn, Sb, In, Bi, Fe, an alkaline earth metal element, or any combination thereof.

In an aspect, ammonium may make up at most <NUM> mol% of the total of ammonium and M, such as at most <NUM> mol%, at most <NUM> mol%, or at most <NUM> mol% of the total of ammonium and M. In another aspect, ammonium may make up at least <NUM> mol% of the total of ammonium and M, such as at least <NUM> mol%, at least <NUM> mol%, or at least <NUM> mol% of the total of ammonium and M. In another aspect, ammonium can be present in a range including any of the minimum and maximum percentages noted herein.

In an aspect, M can be one or more metal elements including an alkali metal element. M includes Li. In another example, M includes Li and another alkali metal, such as Na, K, Cs, Rb, or any combination thereof. In particular instances, M can be a combination of Li and Cs.

In another aspect, M may consist of one or more alkali metal element. For example, M can be Li or a combination of Li and another alkali metal. In another example, M can consist of at least one of Li and Na. In still another example, M can consist of Li and Na.

In particular implementations, Na can make up at most <NUM> mol% of M, such as at most <NUM> mol% of M. For example, M can include from <NUM> mol% to <NUM> mol% of Na. In particular examples, M can include up to <NUM> mol% of Na, or even more particularly, up to <NUM> mol% of Na. In at least one instance, Na can make up from <NUM> mol% to <NUM> mol% of M.

In further particular implementations, Li can make up at least <NUM> mol%, or at least <NUM> mol%, or at least <NUM> mol%, or at least <NUM> mol% of M. In a particular example, M can include from <NUM> mol% to <NUM> mol% Li.

In another instance, Cs can make up at least <NUM> mol% of M, such as at least <NUM> mol%, at least <NUM> mol%, or at least <NUM> mol% of M. In another instance, Cs may make up at most <NUM> mol%, or at most <NUM> mol%, or at most <NUM> mol%, or at most <NUM> mol%, or at most <NUM> mol% of M. In particular instances, Cs may make up at most <NUM> mol% of M.

In an aspect, X can include at least one of Cl, Br, I, and F. For example, X can include Cl or Br. In another example, X can include F. In another example, X can include at least two of Cl, Br, and I. In still another example, X can include all of Cl, Br, and I.

In an embodiment, X may include elements other than halogen. In some implementations, X can include an anion group in addition to a halogen. Such anion group can include amide (-NH<NUM>), -(NH)<NUM> (imide), hydroxide (-OH), borohydride (-BH<NUM>), -BF<NUM>, or a combination thereof. The anion group may be included as an impurity or a dopant. In particular aspects, X can consist of at least one of Cl, Br, F, and I and optionally at least one of amide (-NH<NUM>), hydroxide (-OH), BH<NUM> and -BF<NUM>. For example, X can consist of one or both of Cl and Br and at least one of amide (-NH<NUM>), -(NH)<NUM> (imide), hydroxide (-OH), -BH<NUM> and - BF<NUM>. In a further example, X may consist of F and at least one of amide (-NH<NUM>), hydroxide (-OH), -BH<NUM> and -BF<NUM>. In at least one embodiment, X may be one or more halogen.

In an aspect, Me can include a divalent metal element, a trivalent metal element, a tetravalent metal element, a pentavalent metal element, a hexavalent metal element, or any combination thereof. In instances Me includes more than one metal elements, k can be the average of the total of the valence of each Me metal element. For example, when Me includes a trivalent element and tetravalent element in equal molar quantity, k=(<NUM>+<NUM>)/<NUM>=<NUM>. In a particular aspect, k may be <NUM> or <NUM> or <NUM>.

An exemplary divalent metal element can include an alkaline earth element, such as Mg and/or Ca, or any combination thereof. In particular implementations, Me can include Ca.

In particular implementations, ions having relatively smaller radius, such as Mg, may be particularly suitable when the halogen includes or consist of Cl; and ions having relatively larger radius, such as Ca, may be particularly suitable when the halogen includes or consists of Br. In another particular implementation, including a substituting ion having a radius larger than the base ion may help enlarge ion-conducting channels in the electrolyte material. For example, Me can include Ca and Y, wherein Ca can be suitable to partially substitute Y. In another implementation, a divalent element having a relatively light weight, such as Mg, and Ca, may be preferred. In certain instances, substituting Y with Sr or Ba may result in formation of compounds of SrX<NUM> or BaX<NUM>, which may be an impurity impacting bulk ionic conductivity of the complex metal halide.

An exemplary trivalent metal element can include a rare earth element including Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Pm, Sm, Sc, Tb, Tm, Yb, Sc and Y, a trivalent metal other than rare earth element, such as In, or Bi, or any combination thereof. In particular examples, Me can include Sc, Y, La, Gd, or any combination thereof. In more particular instances, Me can include Y, Gd, or a combination thereof.

An exemplary tetravalent metal element can include Zr, Hf, Ti, Sn, or any combination thereof. In particular examples, Me can include Zr and Hf. In another particular example, Me can include Zr.

An exemplary pentavalent element can include Sb.

In a further aspect, Me can include a rare earth element including Y, Gd, La, and/or Sc, an alkaline earth metal element, 3d transition metals, Zr, Hf, Ti, Sn, Sb, In, Bi, or any combination thereof. In particular examples, Me can include Y, Gd, Zr, or any combination thereof. In particular instances, Me can include Y that is partially substituted by another Me element. For instance, Y may be substituted by a particular content of another Me element that can facilitate improved crystalline structure and/or property of the complex ammonium-containing metal halide. In a particular example, Me can include up to <NUM> mol% of Y and from <NUM> mol% to <NUM> mol% of substitution Me element. In a further example, Y may be partially substituted by an Me element having a suitable effective ionic radius that may allow formation of a stable phase of the complex metal halide. In particular example, the Me element may have an ionic radius that is smaller than the effective ionic radius of La, <NUM> A and at least similar to the effective ionic radius of Li, <NUM> A. In more particular examples, the Me element may have an effective ionic radius from <NUM> A±<NUM>% to <NUM> A±<NUM>%.

In a particular implementation, Me can consist of Gd, Y, Ce, Er, Zr, Yb, or any combination thereof. For example, Me can consists of Y. In another example, Me can consist of Y and at least one of Ce, Er, Zr, and Gd. In a further example, Me consists of Yb and Ce. In another example, Me can consist of two or more of In, Y, Zr, Hf, Sc, and Mg.

In a particular example, M can be Li, Me can be a combination of In, Mg, Zr, and Sc, and X can be Cl or a combination of Cl and an anion group.

In another particular example, M can be Li, Me can be Y, Zr, and Hf, and X can be Cl or a combination of Cl and an anion group.

In another particular example, M can be Na, Me can be Zr, and X can be Cl or a combination of Cl and an anion group.

In particular embodiments, the complex ammonium-containing metal halide can be represented by (NH<NUM>)n(Li(<NUM>-d-e)Na(d)M'(e))<NUM>Li(<NUM>-z)Me<NUM>+(<NUM>-u-p-q-r)Me<NUM>+(u) Me<NUM>+(p) Me<NUM>+(q)Me<NUM>+(r)(Cl(<NUM>-y-w)Br(y)I(w))(<NUM>+u-p+2q+3r-z+n), wherein n><NUM>; <NUM>≤d<<NUM>; <NUM>≤e<<NUM>; (d+e)≤ <NUM>; M' can be Cs, Rb, K, or any combination thereof; Me<NUM>+ is Zr<NUM>+, Hf<NUM>+, Ti<NUM>+, Sn<NUM>+, or any combination thereof; Me<NUM>+ is a trivalent rare earth element, In<NUM>+, Y<NUM>+, Sc<NUM>+, Bi<NUM>+, or any combination thereof; Me<NUM>+ is Mg<NUM>+, Zn<NUM>+, Ca<NUM>+, Sr<NUM>+, Ba<NUM>+, Yb<NUM>+, Eu<NUM>+ or any combination thereof; Me<NUM>+ is Sb<NUM>+, <NUM><=w<=<NUM>; <NUM><=y<=<NUM>; -<NUM>≤z≤<NUM>; <NUM><=u <<NUM>; <NUM><= p <<NUM>; <NUM><= q<<NUM>; and <NUM><=r<<NUM>. In a particular aspect, n= <NUM> or <NUM> or <NUM> or <NUM> or <NUM> and z = <NUM>. In another particular aspect, <NUM>≤z<<NUM>. In a more particular aspect, d = e = <NUM>, p=<NUM>, q=<NUM>, and r=<NUM>, and in even more particular aspect, w=<NUM>.

In another particular embodiment, the ammonium-containing complex metal halide may be represented by (NH<NUM>)nLi<NUM>(Mek+)fX<NUM>+k*f+n, wherein Me can include a rare earth element, Zr, or a combination thereof; n><NUM>; <NUM>≤f≤<NUM>; X includes a halogen and optionally an anion group, such as amide (-NH2), -(NH)<NUM> (imide), hydroxide (-OH), and -BF4; and k may be <NUM> or <NUM> or <NUM>. In an aspect, f is not zero. In particular aspects, f=<NUM>. Particular example of Me may include Y, Gd, Sc, Zr, or a combination thereof. Particular examples of ammonium-containing complex metal halide can include (NH<NUM>)<NUM>Li<NUM>YCl<NUM>, (NH<NUM>)<NUM>Li<NUM>Y<NUM>Gd<NUM>Br<NUM>, (NH<NUM>)<NUM>Li<NUM>Y<NUM>Gd<NUM>Cl<NUM>, (NH<NUM>)<NUM>Li<NUM>InCl<NUM>, (NH<NUM>)<NUM>Li<NUM>Mg<NUM>Y<NUM>Zr<NUM>Cl<NUM>, (NH<NUM>)<NUM>Li<NUM>YBr<NUM>, or the like, or any combination thereof.

In another particular embodiment, the ammonium-containing complex metal halide may be represented by (NH<NUM>)n(Li<NUM>-dNa<NUM>-d)<NUM>LiMek+X<NUM>+k+n, wherein Me can include a rare earth element, Zr, or a combination thereof; n><NUM>; <NUM>≤d<<NUM>; X includes a halogen and optionally an anion group such as (-NH<NUM>), -(NH)<NUM> (imide), hydroxide (-OH), and -BF<NUM>; and k may be <NUM> or <NUM> or <NUM>. In more particular examples, Me may include Y, Sc, Gd, Zr, or a combination thereof. Exemplary particular ammonium-containing complex metal halide of such may include (NH<NUM>)<NUM>(Li<NUM>Na<NUM>)<NUM>YCl<NUM>, (NH<NUM>)<NUM>(Li<NUM>Na<NUM>)<NUM>YBr<NUM>, (NH4)<NUM>Cs<NUM>LiYBr<NUM>, (NH<NUM>)LiCsCl<NUM>, or NH<NUM>Li<NUM>CsCl<NUM>, or the like, or any combination thereof.

In an embodiment, the ammonium-containing complex metal halide can be constituted of At and B(<NUM>-t), wherein <NUM>-<NUM><t≤<NUM>; A includes ammonium; and B is free of ammonium.

In an example, A can be represented by (NH<NUM>)nLi<NUM>-z(Mek+)fX<NUM>-z+k*f+n, and B can be represented by (Li<NUM>-d-eNadMe)<NUM>Li<NUM>-z'(Me'k+)f'X<NUM>-z'+k*f', wherein Me and Me' can independently include a rare earth element, Zr, a divalent metal element, a trivalent metal element other the rare earth, a tetravalent metal element other than Zr, a pentavalent element, a hexavalent element or any combination thereof; M can be K, Rb, Cs, or any combination thereof; <NUM>≤k<<NUM>; <NUM>≤d<<NUM>; <NUM>≤e<<NUM>; -<NUM> ≤ z' ≤ <NUM>; <NUM> ≤ f ≤ <NUM>; <NUM> ≤ f' ≤ <NUM>; <NUM><n, <NUM>≤z≤<NUM>. In a particular instance, d is less than <NUM>. In a further particular instance, z is not zero. In another particular instance, f' is greater than <NUM>. In particular instances, n=<NUM> or <NUM> or <NUM> or <NUM> or <NUM> when z = <NUM>.

In particular examples, A can be represented by (NH<NUM>)nLi<NUM>Mek+X<NUM>+k+n, and B can be represented by (Li, Na)<NUM>LiMe'k+X<NUM>, wherein Me and Me' can independently include a divalent metal element, a trivalent metal element, a tetravalent metal element, a pentavalent element, or any combination thereof; <NUM>≤k<<NUM>; n><NUM>; and X includes at least one halogen. In more particular examples, k may be <NUM> or <NUM> or <NUM>; n may be <NUM> or <NUM> or <NUM> or <NUM>; and Me can include a rare earth element, Zr, or a combination thereof.

In particular examples, A can be represented by (NH<NUM>)nLi<NUM>Mek+X<NUM>+k+n, and B can be represented by (Li, Cs)<NUM>LiMe'k+X<NUM>, wherein Me and Me' can independently include a divalent metal element, a trivalent metal element, a tetravalent metal element, a pentavalent element, or any combination thereof; <NUM>≤k<<NUM>; n><NUM>; and X includes at least one halogen. In more particular examples, k may be <NUM> or <NUM> or <NUM>; n may be <NUM> or <NUM> or <NUM> or <NUM>; and Me can include a rare earth element, Zr, or a combination thereof.

In an embodiment, the ammonium-containing complex metal halide can consist of a single phase including A and B. In particular examples, the single phase may be a solid solution constituted of At and B(<NUM>-t).

In another embodiment, the ammonium-containing complex metal halide can include a plurality of phases. For example, A may be present in a first phase, and the first phase may be free of B. B may be present in a second phase, and the second phase may be free of A. In another example, the second phase may consist of B. In particular examples, the plurality of phases may be present in a eutectic-like intimate mixture.

It is notable A can improve ion conductivity of B, and the ammonium-containing complex metal halide having the composition of At+B(<NUM>-t) can have improved ion conductivity over the complex metal halide having the composition of B.

In an embodiment, the ammonium-containing complex metal halide may have a particular t that can facilitate improved ion conductivity of the electrolyte material. For example, t can be greater than <NUM>-<NUM>, such as at least <NUM>-<NUM>, at least <NUM>-<NUM>, at least <NUM>-<NUM>, at least <NUM>-<NUM>, or at least <NUM>. In another instance, t may be at most <NUM>, such as at most <NUM>, at most <NUM>, or at most <NUM>. Moreover, t can be in a range including any of the minimum and maximum values noted herein. In particular implementations, t may be a bulk ion conductivity enhancer parameter. For instance, in particular applications of an ammonium-containing complex metal halide, a greater t may indicate higher bulk ion conductivity for the ammonium-containing complex metal halide.

In an embodiment, the ammonium-containing complex metal halide can have ionic conductivity in bulk. In an aspect, the ammonium-containing complex metal halide can exhibit an ionic conductivity at least <NUM>/cm, at least <NUM>/cm, at least <NUM>/cm, or at least <NUM>/cm. In another aspect the ammonium-containing complex metal halide can ion conductivity of greater than <NUM>/cm. For example, the bulk ion conductivity can be at least <NUM>/cm, at least <NUM>/cm, at least <NUM>/cm, or at least <NUM>/cm. In another example, the bulk ion conductivity can be at most <NUM>/cm, at most <NUM>/cm, at most <NUM>/cm, at most <NUM>/cm, at most <NUM>/cm, or at most <NUM>/. In a particular example, the bulk ion conductivity can be in a range including any of the minimum and maximum values noted herein.

Ionic conductivity in bulk can be measured at <NUM> and activation energy of <NUM> eV to <NUM> eV. In further instances, the activation energy from <NUM> to <NUM> eV may be used for the temperature from <NUM> to -<NUM>. For the temperature from <NUM> to -<NUM>, the activation energy may be from <NUM> to <NUM> eV. For above <NUM> or below <NUM>, the activation energy can be from <NUM> to <NUM> eV.

In another embodiment, the ammonium-containing complex metal halide can exhibit ionic conductivity in bulk of at least <NUM>/cm to at most <NUM>/cm for a temperature range from -<NUM> to <NUM> or for a temperature range from -<NUM> to <NUM>.

In a further embodiment, the ammonium-containing complex metal halide can include a bulk ion conductivity of at least <NUM>/cm to at most <NUM>/cm for each temperature in the range from -<NUM> to <NUM> at the activation energy of <NUM> eV to <NUM> eV.

In a further embodiment, A can be represented by (NH<NUM>)nMek+Xk+n, and B can be represented by M<NUM>Li(Mek+)fX<NUM>+k*f, wherein M can include at least one alkali metal element, Me can include a rare earth element, Zr, or a combination thereof; and Zr; n=<NUM> or <NUM> or <NUM> or <NUM>; and where <NUM><f≤<NUM>, and k is valence of Me and X can include at least one halogen and optionally, an anion group including (-NH<NUM>), -(NH)<NUM> (imide), hydroxide (-OH), -BH<NUM>, -BF<NUM>, or a combination thereof. In a particular example, Me can be at least one element selected from the group consisting of a rare earth element and Zr. In particular examples, Me can be Y, Zr, Gd, Sc, Er, or any combination thereof. In more particular examples, Me can be Y or Gd or a combination of two or more of Y, Zr, and Gd. In an aspect, M can include Li, Na, Rb, Cs, K, or any combination thereof. In particular examples, M includes Li. In another particular example, M includes Na. In another particular example, M includes Cs. In more particular examples, M can be Li or a combination of Li and at least one of Na and Cs. In another aspect, Li can consist of Li and at least one of Na, Cs, Rb, and K. In a further aspect, M can consist of Li and Na. In still another aspect, M can consist of Na and at least one of Cs, Rb, and K. In an example, X can consist of a halogen and optionally an anion group. In a particular example, the halogen can include at least one, at least two, or at least three of Cl, Br, F, and I.

In an embodiment, A can be represented by (NH<NUM>)<NUM>Mek+X<NUM>+k, and B can be represented by Li<NUM>Mek+X<NUM>+k, wherein Me can include a rare earth element, Zr, or a combination thereof, and X includes one or more halogen and optionally an anion group. In particular examples, Me can be Y, Zr, Gd, Sc, Er, or any combination thereof. In more particular examples, Me can be Y or Gd or a combination of two or more of Y, Zr, and Gd. In an example, X can consist of a halogen and optionally an anion group. In a particular example, the halogen can include at least one, at least two, or at least three of Cl, Br, F, and I.

In an embodiment, A can be represented by (NH<NUM>)<NUM>Li<NUM>Mek+X<NUM>+k, and B can be represented by Li<NUM>MeX<NUM>, wherein Me can include a rare earth element, Zr, or a combination thereof, and X includes one or more halogen and optionally an anion group. In particular examples, Me can be Y, Zr, Gd, Sc, Er, or any combination thereof. In more particular examples, Me can be Y or Gd or a combination of two or more of Y, Zr, and Gd. In an example, X can consist of a halogen and optionally an anion group. In a particular example, the halogen can include at least one, at least two, or at least three of Cl, Br, F, and I.

In particular embodiments, A can be represented by (NH<NUM>)<NUM>Li<NUM>YX<NUM>, and B can be represented by (Li<NUM>-dNad)<NUM>LiMek+X<NUM>+k, wherein Me can include a rare earth element, Zr, or any combination thereof; <NUM>≤d<<NUM>; and X can include one or more halogen and optionally an anion group such as (-NH<NUM>), -(NH)<NUM> (imide), hydroxide (-OH), and -BF<NUM>. In particular examples, X can consist of a halogen and optionally an anion group. In another example, X can consist of at least one halogen and at least one anion group. In a further example, the halogen can include at least one, at least two, or at least three of Cl, Br, F, and I. In a particular example, the halogen can be Cl. In another particular example, the halogen can be Br or a combination of Br and Cl. In yet another particular example, the halogen can be a combination of Cl, Br, and I. In still another particular example, the halogen can be F.

In an embodiment, A can be represented by (NH<NUM>)<NUM>Mek+X<NUM>+k, and B can be represented by (Li<NUM>-dNad)<NUM>LiMek+X<NUM>+k, wherein Me can include a rare earth element, Zr, or any combination thereof; <NUM>≤d<<NUM>; and X can include one or more halogen and optionally an anion group such as (-NH<NUM>), hydroxide (-OH), and -BF<NUM>. In particular examples, d may be greater than <NUM>, such as at least <NUM>. In another particular example, d may be at most <NUM>. In particular examples, Me can include Y, Gd, Zr, Sc, or a combination thereof. In a further example, the halogen can include at least one, at least two, or at least three of Cl, Br, and I. In a particular example, the halogen can be Cl, Br, or a combination of Cl and Br. In another particular example, the halogen can be a combination of Cl, Br, and I. In still another particular example, the halogen can be F.

In a particular embodiment, A can be represented by (NH<NUM>)nYX<NUM>+n,, n=<NUM>, <NUM>, <NUM>, <NUM> and B can be represented by M<NUM>LiREX<NUM>, wherein M can be Li or Li and Na or Li and Cs, RE can include at least one rare earth element, and X includes at least one halogen. In a particular embodiment, A can be represented by (NH<NUM>)<NUM>YX<NUM>, and B can be represented by (Li<NUM>-dNad)<NUM>LiMek+X<NUM>+k, wherein Me can include a rare earth element, Zr, or any combination thereof; <NUM>≤d<<NUM>; and X can include one or more halogen and optionally an anion group such as amide (-NH<NUM>), hydroxide (-OH), and -BF<NUM>. In particular examples, d may be greater than <NUM>, such as at least <NUM>. In another particular example, d may be at most <NUM>. In particular examples, Me can include Y, Gd, Zr, Sc, or a combination thereof. In a further example, the halogen can include at least one, at least two, or at least three of Cl, Br, and I. In a particular example, the halogen can be Cl, Br, or a combination of Cl and Br. In another particular example, the halogen can be a combination of Cl, Br, and I. In still another particular example, the halogen can be F.

In another particular embodiment, A may be represented by (NH<NUM>)nLi<NUM>Mek+F<NUM>+k+n, and B can be represented by (Li<NUM>-dNad)<NUM>LiMek+F<NUM>+k, wherein Me can include a rare earth element, Zr, or any combination thereof; and <NUM>≤d<<NUM>. In implementations, A and/or B may be optionally doped with an anion group including (-NH<NUM>), hydroxide (-OH), -BF<NUM>, or a combination thereof. In particular examples, d may be greater than <NUM>, such as at least <NUM>. In another particular example, d may be at most <NUM>. In another particular example, Me can include Y or a combination of Y and one or more element of Gd, Zr, and Sc.

In another embodiment, A can be represented by (NH<NUM>)n(Li(<NUM>-d),Na(d))<NUM>Li(<NUM>-z) Me<NUM>+(<NUM>-u--p-q-r)Me<NUM>+(u)Me<NUM>+(p)Me<NUM>+(q)Me<NUM>+(r)(Cl(<NUM>-y-w)Br(y)I(w))(<NUM>+u-p+2q+3r-z+n), and B can be represented by (Li(<NUM>-d'),Na(d'))<NUM>Li(<NUM>-z')Me<NUM>+(<NUM>-u-v-w)Me<NUM>+(u)Me<NUM>+(p)Me<NUM>+(q)Me<NUM>+(r)(Cl(<NUM>-y-w)Br(y)I(w))(<NUM>+u-p+2q+3r-z'+n), wherein <NUM>≤d<<NUM>; <NUM>≤d'<<NUM>; <NUM><n, -<NUM>≤z<<NUM>, -<NUM>≤z'<<NUM>; n=<NUM> or <NUM> or <NUM> or <NUM> or <NUM> or <NUM> or <NUM> when z = <NUM>; Me<NUM>+ includes a rare-earth element, In, Bi or any combination thereof; Me<NUM>+ is Zr<NUM>+, Hf<NUM>+, Ti<NUM>+, Sn<NUM>+, Th<NUM>+, or any combination thereof; Me<NUM>+ Mg<NUM>+, Ca<NUM>+, Sr<NUM>+, Ba<NUM>+, or any combination thereof; Me<NUM>+ is Sb<NUM>+, <NUM><=x<=<NUM>; ; <NUM><=y<=<NUM>; -<NUM><z<<NUM>; <NUM><=u <<NUM>; <NUM><= p <<NUM>; <NUM><= q<<NUM>; <NUM><=r<<NUM>; and w<=<NUM>. When z=<NUM>, A can be stoichiometric. When z is not zero, A can be non-stoichiometric. In a particular instance, -<NUM><z<<NUM>. In a more particular aspect, d = e = <NUM>, p=<NUM>, q=<NUM>, and r=<NUM>, and in even more particular aspect, w=<NUM>.

In certain instances, A may be represented by NH<NUM>X and B may be a complex metal halide compound having a general formula of MM'X. An example of such compound can include LiCsCl<NUM> and Li<NUM>CsCl<NUM>. The ammonium-containing complex metal halide can be an eutectic-like composition of NH<NUM>X +LiCsCl<NUM> or NH<NUM>X +LiCsCl<NUM>.

In an embodiment, A and B can include the same halogen element. In particular examples, the halogen element of A and B can be the same. In at least one embodiment, A may be free of alkali metal. In another embodiment, A and B can include the same alkali metal. In particular examples, the alkali metal of A and B can be the same. In more particular examples, A and B can include the same mol% of each alkali metal for the total of alkali metal in respective compound. In a further embodiment, A and B can include the same Me element, such as the same divalent element, trivalent element, tetravalent element, and/or pentavalent element. For example, A and B can include the same rare earth element. In particular examples, the rare earth element of A and B can be the same. In another example, A and B can include Zr. In more particular examples, A and B can include the same mol% of each Me element for the total of Me in the respective compound.

In a particular implementation, A can be (NH<NUM>)<NUM>Li<NUM>YCl<NUM>, and B can be Li<NUM>YCl<NUM>. In another particular implementation, A can be (NH<NUM>)<NUM>Li<NUM>YBr<NUM>, and B can be Li<NUM>YBr<NUM>. In yet another particular implementation, A can be (NH<NUM>)<NUM>(Na<NUM>,Li<NUM>)<NUM>LiYCl<NUM> and B can be (Na<NUM>,Li<NUM>)<NUM>LiYCl<NUM>. In still another particular implementation, A can be (NH<NUM>)<NUM>(Na<NUM>,Li<NUM>)<NUM>LiYBr<NUM> and B can be (Na<NUM>,Li<NUM>)<NUM>LiYBr<NUM>. In still another particular implementation, A can be (NH<NUM>)<NUM>Li<NUM>Y<NUM>Gd<NUM>Br<NUM> and B can be Li<NUM>Y<NUM>Gd<NUM>Br<NUM>. In still another particular implementation, A can be (NH<NUM>)<NUM>Li<NUM>GdBr<NUM> and B can be Li<NUM>GdBr<NUM>. In still another particular implementation, A can be (NH<NUM>)<NUM>Li<NUM>Y<NUM>Zr<NUM>Br<NUM> and B can be Li<NUM>Y<NUM>Zr<NUM>Br<NUM>. In still another particular implementation, A can be (NH<NUM>)<NUM>(Na<NUM>,Li<NUM>)<NUM>LiY<NUM>Zr<NUM>Br<NUM> and B can be (Na<NUM>,Li<NUM>)<NUM>LiY<NUM>Zr<NUM>Br<NUM>. In another example, A may be represented by NH<NUM>Cl, and B may be LiCsCl<NUM>. In another example, A may be represented by NH<NUM>Cl and B may be Li<NUM>CsCl<NUM>. It is to be appreciated that A and/or B may be optionally doped with an anion group.

In a further embodiment, A may be constituted of (NH<NUM>)nM<NUM>Mek+X<NUM>+k+n and (NH<NUM>)nMek+X<NUM>+k+n and B can be represented by M<NUM>Mek+X<NUM>+k, wherein <NUM><n≤<NUM>; M can include Li; Me can include a rare earth element, Zr, or any combination thereof. In particular examples, n = <NUM> or <NUM> or <NUM> or <NUM>. In another particular example, M can be Li or a combination of Li and Na. In further particular examples, RE can include Y, Gd, Zr, or a combination thereof. In another embodiment, (NH<NUM>)nM<NUM>Mek+X<NUM>+k+n and (NH<NUM>)nMek+X<NUM>+k+n may be present in different phases. In still another embodiment, the ammonium-containing complex metal halide can consist of a single phase including A and B, wherein A can be constituted of (NH<NUM>)nM<NUM>Mek+X<NUM>+k+n and (NH<NUM>)nMek+X<NUM>+k+n.

In a further embodiment, a simple metal halide, such as rare earth halide (e.g., YCl<NUM>) and/or alkali metal halide (e.g., LiCl), may be generated due to incomplete reactions between raw materials used to form the ammonium-containing complex metal halide. The simple metal halide may be present as an impurity of the ammonium-containing complex metal halide. In an embodiment, the ammonium-containing complex metal halide may include at most at most <NUM> wt% for the total weight of the ammonium-containing complex metal halide, such as at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, at most <NUM> wt%, or at most <NUM> wt% for the total weight of the ammonium-containing complex metal halide. In particular examples, the simply metal halide may be present in an even lower content, such as at most <NUM> at% or at most <NUM> at%. In an example, the simple metal halide may be present in a different phase than A and B. In embodiments, the ammonium-containing complex metal halide can be essentially free of a simply metal halide. For instance, the metal halide may be less than <NUM> at%. Impurity can be detected by XRD analysis coupled with Rietveld refinements for quantitative analysis through the presence of characteristic diffraction peaks corresponding to the parasitic phases. Rietveld Refinements (RR) can be used to analyze the shape and position of the peaks at an XRD diagram to identify quantitavely the contribution of the various phases by collecting the 2θ data at XRD diffraction with a small incrementation of 2θ angle and converting the XRD data into ratio of different phases. When a impurity phase is presented in the powder sample at the molar or mass quantity below ~ <NUM>%-<NUM>%, the impurity may not generate an XRD peak strong enough to be used for identification of the impurity phase by XRD coupled with Rietveld Refinements. Other analysis may be used to determine impurity phase at low quantity. An exemplary analysis may include LECO.

In an embodiment, the electrolyte material can consist of the ammonium-containing complex metal halide. In an aspect, the electrolyte material can consist of the ammonium-containing complex metal halide including a single phase of the ammonium-containing complex metal halide and one or more impurity phases when impurity is present. In particular, the content of one or more impurity phases can be reduced compared to a conventional complex metal halide. In a further aspect, the electrolyte material can consist of the ammonium-containing complex metal halide including a plurality of phases. For example, the electrolyte material can consist of the ammonium-containing complex metal halide consisting of phases A and B. In an aspect, the electrolyte material may be used as a raw material for forming an electrolyte, an electrode, or another component of an electrochemical device.

In an embodiment, a solid state electrolyte can include the solid electrolyte material. The solid state electrolyte can have improved ion conductivity compared to solid state electrolyte including conventional complex lithium-based halide that does not contain ammonium. In a particular example, the solid state electrolyte can consist of the solid electrolyte material. In more particular examples, the solid state electrolyte can consist of the ammonium-containing complex metal halide.

In an embodiment, a composite ion conductive layer can include the electrolyte material and an organic material. The organic material can include as a binder material, a polymeric electrolyte material, or a combination thereof. In another example, the composite ion conductive layer may include a plasticizer, a solvent, or a combination thereof. An exemplary organic material can include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, polypropylene, an ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, natural butyl rubber (NBR), paraffin wax, polypropylene carbonate, polyisobutylene, polyvinyl pyrrolidone, polymethyl methacrylate, poly(propylene oxide), polyvinyl chloride, poly(vinylidene fluoride), poly(acrylonitrile), poly(dimethysiloxane), poly[bis(methoxy ethoxyethoxide)-phosphazene], polyethylene carbonate, polypropylene glycol, polycaprolactone, poly(trimethylene carbonate), hydrogenated nitrile butadiene rubber, poly(ethylene vinyl acetate), high density polyethylene, low density polyethylene, polyurethane, or any combination thereof. In another example, the composite ion conductive layer can include a lithium salt. An exemplary lithium salt can include LiSbF<NUM>, LiN(SO<NUM>CF<NUM>)<NUM>, LiN(SO<NUM>C<NUM>F<NUM>)<NUM>, LiN(SO<NUM>CF<NUM>)(SO<NUM>C<NUM>F<NUM>), LiC(SO<NUM>CF<NUM>)<NUM>, LiAsF<NUM>, LiClO<NUM>, LiPF<NUM>, LiBF<NUM>, LiCF<NUM>SO<NUM>, or any combination thereof.

In another embodiment, a mixed electron and ion conductive layer can include the solid electrolyte material. In an aspect, the mixed electron and ion conductive layer can further include a cathode active material. An example of the cathode active material can include, but not limited to, lithium-containing transition metal oxides, such as Li(Ni,Co,Al,Mn)O<NUM> and LiCoO<NUM>, transition metal fluorides, polyanions and fluorinated polyanion materials, and transition metal sulfides, transitions metal oxyfluorides, transition metal oxysulfides, transition metal oxynitrides, or the like, or any combination thereof.

In another aspect, the mixed ion and electron conductive layer can include an anode active material. An exemplary anode active material can include carbon materials, such as artificial graphite, graphite carbon fibers, resin baking carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-baked carbon, polyacene, pitch-based carbon fibers, vapor-grown carbon fibers, natural graphite, non-graphitizable carbon, or the like, metal materials including lithium metal, lithium alloy, or the like, oxides, nitrides, tin compounds, silicon compounds, or any combination thereof.

In an embodiment, a solid state lithium battery can include an electrolyte disposed between an anode and a cathode. Referring to <FIG>, a portion of a cross section of an exemplary solid state battery <NUM> is illustrated. The electrolyte layer <NUM> can be any of the electrolyte or composite layer noted in embodiments herein. The anode <NUM> overlies the electrolyte <NUM>. In an embodiment, the anode <NUM> can include the solid electrolyte material and an anode active material. In particular instances, the anode <NUM> may be a <NUM> dimensionally structured anode. In another embodiment, the anode <NUM> may be a metal anode. For instance, the anode may consist of lithium. The cathode <NUM> may be disposed on the other side of the electrolyte <NUM> opposite the anode <NUM>. The cathode <NUM> can include the solid electrolyte material and an active cathode material. In a particular embodiment, the cathode <NUM> may be a <NUM> dimensionally structured cathode.

It is notable the conventional synthesis of a complex halide based on ammonium-halide is not applicable for forming the ammonium-containing complex metal halide, as some trivalent metal halides and tetravalent metal halides (i.e., rare earth halides) tend to form stable hydrate phases, rendering it difficult to completely remove the water molecules from the metal halide hydrates. Increasing the temperature can result in formation of undesired metal oxyhalide or metal oxyhydrate halide compounds at a higher concentration.

Referring to <FIG>, a process for forming the solid electrolyte material <NUM> is illustrated.

The process <NUM> may start at block <NUM>. A reaction mixture may be formed including ammonium halide, metal compounds including one or more oxides of metal Me, alkali metal carbonate (e.g., lithium carbonate), and hydrochloric acid. In another example, sulfates, hydroxides, hydrates, oxalates, or other basic salts including lithium or Me metal may be used as raw materials in lieu of lithium carbonates and/or oxides of metal Me. Me can include a divalent, trivalent, tetravalent, pentavalent, hexavalent element, or a combination thereof, as noted in embodiments herein. In a particular instance, the metal compound can consist of alkali metal compounds, such as alkali metal halide.

An intermediate reaction product can include hydrated salts containing metal halides (e.g., rare earth halides). The moisture in the hydrated salt can be replaced with NH<NUM>X to form (NH<NUM>)nMek+Xn+k, wherein n><NUM>. An exemplary reaction is illustrated below. <NUM>*Li<NUM>CO<NUM> + RE<NUM>O<NUM> + <NUM>*HX+ <NUM>*NH<NUM>X ---> <NUM>*(NH<NUM>)<NUM>REX<NUM> + <NUM>*LiX + <NUM>*H<NUM>O+ <NUM>*CO<NUM>.

In an instance, the reaction products may be filtered to remove larger particles to facilitate subsequent solid-state reactions. Larger particles can include impurities that come with any of the raw materials, remaining particles of the raw materials, carbon, or any combination thereof.

The reaction products can be dried to facilitate a solid state reaction of (NH<NUM>)nMek+X<NUM>+k and MX (e.g., LiX), wherein M can include one or more alkali metal element as noted in embodiments herein. Drying may be performed under vacuum or reduced pressure. The atmosphere may be, but not limited to, air, dry air, or nitrogen. Heat may be applied to aid evaporation of water. The heating temperature can be from <NUM> to <NUM>. Drying may be conducted until a trace amount of water is left in the mixture, such as from <NUM> wt% to <NUM> wt%.

The process <NUM> can continue to block <NUM>. In an instance, the solid state reaction of (NH<NUM>)nMek+X<NUM>+k and MX may be performed in a dry and neutral atmosphere. N<NUM> or Ar flow may be used to facilitate removal of the trace amount of water. In a particular instance, partially decomposing (NH<NUM>)<NUM>Mek+X<NUM>+k may be performed simultaneously with the solid state reaction.

In particular instances, the decomposition and solid state reaction may be carried out in a crucible made of a material that is inert to the reactants and products. For example, the crucible may be made of quartz, alumina, silica-alumina, BN, glassy carbon, or graphite. Graphite can have a pyrolytic carbon coating in particular implementations. In particular examples, the heating temperature can be in a range from <NUM> to <NUM> to allow partial sublimation of ammonium halide.

The process <NUM> may continue to block <NUM>, forming the ammonium-containing complex metal halide. The resulted product after heating can be the ammonium-containing complex metal halide. For example, the ammonium-containing complex metal halide may be represented by (NH<NUM>)nM<NUM>-z(Mek+)fX<NUM>+n-z+k*f, wherein n><NUM>; <NUM>≤z<<NUM>; <NUM>≤k<<NUM>; <NUM>≤f≤<NUM>. In particular instance, the ammonium -containing complex metal halide may be represented by (NH<NUM>)nM<NUM>-zMek+X<NUM>+n-z+k, wherein n><NUM>; <NUM>≤z<<NUM>; <NUM>≤k<<NUM>.

Known techniques can be used to form an electrolyte a composite ion conductive layer, an anode, a cathode, or another component of a solid state lithium battery with the solid electrolyte material. Such techniques include, but not limited to, casting, molding, deposition, printing, pressing, heating, or the like, or any combination thereof. In particular implementations, for forming a multi-layer structure, the layers, such as electrolyte and anode and/or cathode may be formed separately and then laminated to form a multi-layer structure. Alternatively, a stack of green electrolyte and anode and/or cathode layers may be formed followed by a further treatment, such as pressing, extrusion, heating, drying, voltage application or any combination thereof to form the finally formed multi-layer structure.

In an example, the electrolyte material may be used as a coating for another component of an electrochemical device, such as a solid state battery. For instance, the electrolyte material can be deposited on a separator, such as an electrolyte layer.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention.

Ammonium-containing complex metal halide samples were synthesized according to embodiments herein. Compositions and properties of the compound are included in Table <NUM>. The samples are pressed dense ceramic pellets. Some samples are polished. Ion conductivity in bulk is determined by AC electrochemical impedance spectroscopy within <NUM> and <NUM> using a sinusoidal voltage amplitude between <NUM> and <NUM> mV, and in a blocking electrode configuration using Au plated electrodes and/or in a non-blocking electrode configuration using porous graphite anode.

The contents of the impurities of simple metal halide (e.g., LiX and/or MeXk) that were present in the samples are included in Table <NUM> and were determined by X-ray diffraction analysis coupled with Rietveld refinements for quantitative analysis.

Additional samples were formed. Sample <NUM> were synthesized by using a stoichiometric mixture of LiBr and YBr<NUM> compounds in welded quartz ampoule under vacuum with heat up to <NUM>. After the reaction mixture melted, a soak time of up to an hour at <NUM> was applied to ensure reaction products are dissolved in the self flux. Then the temperature of the quartz ampoule was dropped down promptly (in <NUM>-<NUM> minutes) to <NUM> to help minimize partial decompositions of the incongruent Li<NUM>YBr<NUM> phase. Then the temperature of the quartz ampoule was decreased progressively to room temperature at a rate <NUM>-<NUM>/hour.

Samples <NUM> and <NUM> were synthesized according to embodiments herein voluntarily keeping residual ammonium. The quantity of residual ammonium was estimated by posterior overheating of a compound up to the malting temperature permitting to fully sublimate ammonium halide from the charge. Ionic conductivity in bulk of the samples were measured in the similar manner as described in Example <NUM>.

Reference herein to a material including one or more components may be interpreted to include at least one embodiment wherein the material consists essentially of the one or more components identified. The term "consisting essentially" will be interpreted to include a composition including those materials identified and excluding all other materials except in minority contents (e.g., impurity contents), which do not significantly alter the properties of the material. Additionally, or in the alternative, in certain non-limiting embodiments, any of the compositions identified herein may be essentially free of materials that are not expressly disclosed. The embodiments herein include range of contents for certain components within a material, and it will be appreciated that the contents of the components within a given material total <NUM>%.

Claim 1:
A solid electrolyte material, comprising a material including an ammonium-containing complex metal halide represented by (NH<NUM>)nM<NUM>-z(Mek+)fXn+<NUM>-z+k*f, wherein <NUM><n<<NUM>, <NUM>≤z<<NUM>, <NUM>≤k<<NUM>, <NUM>≤f≤<NUM>; M comprises an alkali metal element including Li, X comprises a halogen, and Me comprises a rare earth element, Zr, Hf, Ti, Sn, Sb, In, Bi, an alkaline earth metal element, or any combination thereof.