Patent Description:
Batteries are a useful source of stored energy that can be incorporated into a number of systems. Rechargeable lithium-ion ("Li-ion") batteries or cells are attractive energy storage systems for portable electronics and electric and hybrid-electric vehicles because of their high specific energy (measured in Wh/kg) compared to other electrochemical energy storage devices. However, current Li-ion cells are reaching their maximum energy storage capability (approximately <NUM> Wh/kg). With this limitation, these cells are unable to provide a safe, low-cost battery with storage sufficient for electric vehicles with mile ranges in excess of <NUM> miles. In order achieve longer ranges, a new generation of cells with higher energy densities (at least <NUM> Wh/kg), low cost (less than $<NUM>/kWh), improved safety, and low environmental impact is needed. One option includes use of cells with a form of lithium metal ("Li-metal") incorporated into the negative electrode. These cells afford exceptionally high specific energy and energy density compared to batteries with conventional carbonaceous negative electrodes.

As an example, when high-specific-capacity negative electrodes such as lithium are used in a battery, the maximum benefit of the capacity-increase over conventional systems is realized when a high-capacity positive electrode active material is also used. Conventional lithium-intercalating oxides (e.g., LiCoO<NUM>, LiNi<NUM>Co<NUM>Al<NUM>O<NUM>, and Li<NUM>Ni<NUM>Co<NUM>Mn<NUM>O<NUM>) are typically limited to a theoretical capacity of approximately <NUM> mAh/g (based on the mass of the lithiated oxide) and a practical capacity of <NUM> to <NUM> mAh/g. In comparison, the specific capacity of lithium metal is about <NUM> mAh/g. The highest theoretical capacity achievable for a lithium-ion positive electrode is <NUM> mAh/g (based on the mass of the lithiated material), which is shared by Li<NUM>S and Li<NUM>O<NUM>. Other high-capacity materials including BiF<NUM> and FeF<NUM> are also available. The foregoing materials, however, react with lithium at a lower voltage compared to conventional oxide positive electrodes, thereby limiting the theoretical specific energy. The theoretical specific energies of the foregoing materials, however, are very high (greater than <NUM> Wh/kg, compared to a maximum of approximately <NUM> Wh/kg for a cell with lithium negative and conventional oxide positive electrodes).

Thus the advantage of using a Li-metal negative electrode (sometimes referred to as an anode) is the much higher energy density of the entire cell, as compared to cells with graphitic or other intercalation negative electrode. A disadvantage of using pure Li metal is that lithium is highly reactive. Accordingly, the lithium metal has a propensity to undergo morphology changes, which cause structures having a high surface area to form on and around the negative electrode when the cell is being charged. Exemplary high surface area structures include dendrites and mossy structures. One factor inhibiting the commercialization of Li-metal based cells is the lack of a suitable thin film electrolyte that inhibits the formation of these high surface area structures as well as providing other beneficial functions for the cell.

Existing candidate solid electrolytes have insufficient conductivities, low transference numbers, and poor mechanical properties (e.g., polymers), poor processability and high boundary resistances (e.g., ceramics), or severe chemical instabilities to air and water (e.g., sulfidic materials). Many research groups are seeking ways to combine candidate materials, such as polymers and ceramics, to achieve a single composite material with the best of all available properties. The vast majority of this work has been performed on polymer-ceramic composites in which both the polymeric and ceramic phases of the composite are ionically conductive. However, such composites suffer from some problems that limit their utility. In particular, polymer-ceramic composites cannot be sintered due to the organic phase, and conductivity across grains in unsintered ceramics is typically extremely poor. Additionally, interfacial conductivity between the polymeric and ceramic phases is typically very poor. Li-ion conductivity pathways tend to be exclusively through the polymer, but the polymeric phase is not sufficiently mechanically strong so as to resist dendrite penetration. <CIT> discloses an ion-conducting composite electrolyte comprising path-engineered ion-conducting ceramic electrolyte particles. <CIT> describes ion-conducting hybrid membranes. In <CIT>, a method for manufacturing a functional layer for a lithium cell is described. <CIT> teaches a flexible composite solid state battery.

What is needed, therefore, is a thin (less than <NUM> micron), flexible, strong, dendrite resistant, and inexpensive single-ion-conducting membrane separator with sufficiently high ionic conductivity (greater than 1E-<NUM>/cm). Aside from enabling Li-metal batteries, such separators have exceptional utility in batteries more broadly. These separators may be used with other chemistries. If the transference numbers are high, and if the membranes are able to adequately block battery solvents and salts, these separators may additionally be used to separate anolyte from catholyte in an otherwise traditional battery, enabling, for example, use of higher voltage cathodes, or chemistries in which a single stable liquid electrolyte is not yet available. These separators may also be used to modulate salt concentration gradients in liquid, gel, or polymeric batteries, thereby enabling improved rate capability and faster charging/discharging. The membrane separators disclosed herein are configured to address any one of these, or related, problems.

A battery cell in according to the invention includes a positive electrode, a negative electrode, and at least one thin-film composite electrolyte structure disposed between the positive electrode and the negative electrode, the thin film composite electrolyte structure being a composite electrolyte structure of any one of appended claims <NUM> to <NUM>.

A composite electrolyte structure according to the invention includes a first side and a second side defining a thickness, a non-conducting organic phase portion extending from the first side to the second side, and a plurality of ion-conducting inorganic phase structures dispersed throughout the non-conducting organic phase portion, each of the plurality of ion-conducting inorganic phase structures spanning the thickness such that a first portion of each of the plurality of ion-conducting inorganic phase structures is exposed on the first side and a second portion of each of the plurality of ion-conducting inorganic phase structures is exposed on the second side, each of the plurality of ion-conducting inorganic phase structures defining a respective interface with the non-conducting organic phase portion, each of the respective interfaces includes an unbroken chain of at least one of ionic bonds and covalent bonds so as to firmly adhere the non-conducting organic phase portion to each of the plurality of ion-conducting inorganic phase structures, wherein each of the plurality of ion-conducting inorganic phase structures is formed from a monocrystalline material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second layer of a second adhesion promoter disposed on the first layer, or wherein each of the plurality of ion-conducting inorganic phase structures is formed from an amorphous material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second adhesion promoter reacted with the first layer, or wherein each of the plurality of ion-conducting inorganic phase structures is formed from a glass ceramic material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second adhesion promoter grafted on the first layer.

Described, but not claimed per se, is a method for forming a thin-film, composite electrolyte structure including preparing a plurality of particles from an ion-conducting inorganic phase, the particles having an average particle size that is one size of a range of sizes from <NUM> to <NUM> microns, improving an adhesion characteristic of the particles by at least one of applying an adhesion promoter to surfaces of the particles and using at least one surface modification agent to modify the surfaces of the particles, and encapsulating the particles with an organic phase formed as a continuous thin-film layer with a first side and a second side facing opposite the first side, each particle having a first surface portion exposed on the first side and a second surface portion exposed on the second side.

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification.

<FIG> depict a ceramic-polymer composite electrolyte <NUM> in the form of a thin, disk-shaped separator or membrane <NUM> in accordance with one embodiment. The composite electrolyte <NUM> includes at least one ion-conducting inorganic phase <NUM> (hereinafter the "primary inorganic phase") and at least one non-conducting organic phase <NUM> (hereinafter the "primary organic phase"). The primary organic phase <NUM> is a carbon-containing phase and is not an ionic conductor. This non-conducting attribute enables the primary organic phase <NUM> to direct the majority of the ionic current that traverses the composite electrolyte <NUM> through the primary inorganic phase <NUM>. The composite electrolyte <NUM> in some embodiments includes one or more additional non-conducting inorganic phases (not shown) on one or more surfaces of the primary inorganic phase <NUM>.

The primary inorganic phase <NUM> in the embodiment shown is composed of particles or structures <NUM> that traverse the entire thickness (t) of the membrane <NUM>. The particles or structures <NUM> in some embodiments are amorphous, such as in a Li-ion conducting glass. In other embodiments, the particles or structures <NUM> are single-crystal particles with few or no grain boundaries per particle such that that the thickness (t) of the composite electrolyte <NUM> is the same order as the grain size in the primary inorganic phase <NUM>. The particles or structures <NUM> in yet further embodiments are grown or sintered superstructures, such as nanowires or polycrystalline particles. The arrangement of the particles <NUM> in the composite electrolyte <NUM> ensures that substantially every particle <NUM> has a first exposed surface portion <NUM> on a first side <NUM> of the electrolyte <NUM> and a second exposed surface portion <NUM> on a second side <NUM> of the electrolyte <NUM>. The first exposed surface portions <NUM> and the second exposed surface portions <NUM> of the particles <NUM> are generally opposed to another on the opposite sides <NUM>, <NUM> of the electrolyte <NUM>.

As best shown in <FIG>, the primary organic phase <NUM> contacts the particles <NUM> of the primary inorganic phase <NUM> along respective interfaces <NUM> throughout the membrane <NUM>. Since the primary inorganic phase <NUM> traverses the entire thickness (t) of the composite electrolyte <NUM>, the ionic current traverses very few inorganic-organic interfaces and sintering of the composite material after assembly is substantially minimized if not eliminated entirely. This feature of the composite electrolyte <NUM> minimizes the effect of interfacial resistance between media. Additionally, modifications can further improve the interfacial resistance between the composite electrolyte <NUM> and other parts of a battery cell that incorporates the composite electrolyte, such as other electrolytes, cathode or anode materials, and the like.

The interfaces <NUM> between the primary inorganic phase <NUM> and the primary organic phase <NUM> are engineered to possess strong adhesion characteristics. An unbroken chain of ionic bonds and/or covalent bonds is formed at the interfaces to promote strong adhesion therebetween. As used herein, an "unbroken chain" of one or more of ionic bonds and covalent bonds means that the number of actual bonds along the interface between the inorganic phase and the organic phase corresponds substantially with the number of possible bonds at the interface. In other words, the interface is configured to maximize the ionic and/or covalent bonds between the inorganic and organic phases at the respective interfaces such that there are virtually no discontinuities in bonding along the interfaces. In other embodiments, one or more of adhesion promotors and other surface modification agents are used to promote strong adhesion between the primary inorganic phase <NUM> and the primary organic phase <NUM>. In the resulting composite electrolyte <NUM> depicted in <FIG>, the primary inorganic phase <NUM> confers ionic conductivity on the membrane <NUM> and the primary organic phase <NUM> confers mechanical cohesion and flexibility on the membrane <NUM>.

The interfaces <NUM> between the primary inorganic phase <NUM> and the primary organic phase <NUM> are configured with a variety of features that promote the strong bonding between the primary phases <NUM>, <NUM>. In some embodiments, the particles <NUM> of the primary inorganic phase <NUM> are functionalized and then subjected to a blending process in order to promote strong bonding with the primary organic phase <NUM> (e.g., process <NUM> described with reference to <FIG>). In other embodiments, the particles <NUM> of the primary inorganic phase <NUM> are subjected to a deposition process, an annealing process, a coating process, and a grouping/arranging process, and then subjected to another coating process in order to promote strong bonding with the primary organic phase <NUM> (e.g., process <NUM> described with reference to <FIG>). In yet other embodiments, the particles <NUM> of the primary inorganic phase <NUM> are subjected to a deposition process and a reaction process or a grafting process, and then subjected to a blending process in order to promote strong bonding with the primary organic phase <NUM> (e.g., process <NUM> described with reference to <FIG>). In still further embodiments, the particles <NUM> of the primary inorganic phase <NUM> are subjected to a coating process and a grafting process, and then a blade-casting process in order to promote strong bonding with the primary organic phase <NUM> (e.g., process <NUM> described with reference to <FIG>).

<FIG> depicts an electrochemical cell <NUM>. The electrochemical cell <NUM> includes an anode <NUM>, a cathode <NUM> with an aluminum ("Al") current collector <NUM>, a separator <NUM>, and a composite electrolyte structure <NUM>. The anode <NUM> in the embodiment shown includes lithium metal, a lithium alloy metal, or a mesh filled with lithium metal or lithium alloy metal. The anode <NUM> is sized such that it has at least as much capacity as the cathode <NUM>, and preferably at least <NUM>% excess capacity. The Al current collector <NUM> is typically less than <NUM> microns in width and preferably less than <NUM> microns. In some embodiments, the Al current collector <NUM> has a surface treatment.

The cathode <NUM> includes a mixture of at least an active material and a matrix configured to conduct the primary ions of relevance to the cell <NUM>. The active material in various embodiments includes a sulfur or sulfur-containing material (e.g., PAN-S composite or Li<NUM>S); an air electrode; Li-insertion materials such as NCM, LiNi<NUM>Mn<NUM>O<NUM>, Li-rich layered oxides, LiCoO<NUM>, LiFePO<NUM>, LiMn<NUM>O<NUM>; Li-rich NCM, NCA, and other Li intercalation materials, or blends thereof; or any other active material or blend of materials that react with and/or insert Li cations and/or electrolyte anions.

The matrix in various embodiments includes Li-conducting liquid, gel, polymer, or other solid electrolyte. Solid electrolyte materials in the cathode <NUM> may further include lithium conducting garnets, lithium conducting sulfides (e.g., Li<NUM>S-P<NUM>S<NUM>) or phosphates, Li<NUM>P, LIPON, Li-conducting polymer (e.g., polyethylene oxide (PEO) or polycaprolactone (PCL)), Li-conducting metal-organic frameworks, Li<NUM>N, Li<NUM>P, thio-LISiCONs, Li-conducting NaSICONs, Li<NUM>GeP<NUM>S<NUM>, lithium polysulfidophosphates, or other solid Li-conducting material. Other materials in the cathode <NUM> may include electronically conductive additives such as carbon black, binder material, metal salts, plasticizers, fillers such as SiO<NUM>, or the like. The cathode materials are selected to allow sufficient electrolyte-cathode interfacial area for a desired design. The cathode <NUM> may be greater than <NUM> micron in thickness, preferably greater than <NUM> microns, and more preferably greater than <NUM> microns. In one embodiment, the composition of the cathode <NUM> includes approximately <NUM> to <NUM> weight percent active material, approximately <NUM> to <NUM> weight percent carbon additive, and <NUM> to <NUM> weight percent catholyte.

Although the cell <NUM> in the embodiment of <FIG> is shown with one separator <NUM> and one composite electrolyte structure <NUM>, the cell <NUM> in different embodiments can omit the separator <NUM> or include more than one composite electrolyte structure <NUM>. The composite electrolyte structure <NUM> can have different positions relative to the anode <NUM> and the cathode <NUM> in different embodiments of the cell <NUM>. For example, <FIG> depicts the cell <NUM> with the composite electrolyte structure <NUM> positioned between the separator <NUM> and the anode <NUM>. <FIG> depicts another embodiment of the cell <NUM> in which the composite electrolyte structure <NUM> is positioned between the separator <NUM> and the cathode <NUM>. In yet another embodiment (not shown), a first composite electrolyte structure <NUM> is positioned between the separator <NUM> and the anode <NUM> and a second composite electrolyte structure <NUM> is positioned between the separator <NUM> and the cathode <NUM>.

The anode <NUM> in some embodiments additionally or alternatively includes a composite electrode with a mixture of active material (e.g. Li, Li<NUM>Ti<NUM>O<NUM>, Si or intermetallic compounds), an ionically conductive matrix (e.g., solid polymer electrolyte, liquid electrolytes, ceramic electrolytes (e.g., nanowires), solid polyelectrolytes, or combinations thereof), and electronically conductive additives (e.g., carbon black). The anode <NUM> in these embodiments can also include an anode current collector (e.g. Cu-foil with or without surface treatment).

The anode <NUM> in further embodiments additionally or alternatively includes a matrix that conducts the primary ions of relevance to the cell <NUM>. This matrix could include liquid or gel electrolytes, polymeric electrolytes such as polyethylene oxide (PEO), or ceramic or glassy sulfidic or oxidic ion conductors, or combinations. The matrix could further include binder(s), metal salts, plasticizers, fillers such as SiO<NUM>, or the like. The matrix may also contain carbon configured to provide electrical conductivity. The materials in the matrix on the anode side need not be identical to the material in the cathode side.

The anode <NUM> in still further embodiments additionally or alternatively includes a graphitic Li-ion battery anode with or without modifications. The anode <NUM> in yet still further embodiments additionally or alternatively includes Na or Mg metal or suitable intercalation compounds for Na or Mg metal ions.

The composite electrolyte structure <NUM><NUM> in various embodiments comprises the composite electrolyte <NUM> of <FIG> and any variants thereof formed by the processes <NUM>, <NUM>, <NUM>, and <NUM> described herein with reference to <FIG>, a ceramic thin layer prepared as by sputtering (e.g. LiPON), a "free standing" ceramic or glass ceramic layer (e.g. LATP), a polymer-ceramic composite in which the organic phase also conducts ions, and a polymer or gel including PS-block-PEO. The requirements of the composite electrolyte structure <NUM><NUM> depend in part on whether the composite electrolyte structure <NUM> contacts the anode <NUM> or the cathode <NUM> in a cell. In embodiments in which the composite electrolyte structure <NUM> directly contacts a Li anode (<FIG>), the composite electrolyte structure <NUM> must be stable against, or form a stable solid electrolyte interphase (SEI) against, Li metal. The composite electrolyte structure <NUM> must also function to suppress lithium dendrites or be resistant to Li dendrite penetration at current densities of at least <NUM>. 1mA/cm2 when the composite electrolyte structure <NUM> directly contacts a Li anode.

<FIG> depict different processes to form variants of the composite electrolyte structure <NUM> of <FIG>. <FIG> illustrates a first process <NUM> to form a first variant of the ceramic-polymer composite electrolyte <NUM> of <FIG>. Initially, a polycrystalline Li-ionic conducting material, such as lithium lanthanum titanium oxide ("LLTO"), is synthesized with an average particle size of <NUM> microns (block <NUM>). These particles are then functionalized with organophosphonic acids or phosphonate esters such as <NUM>-decylphosphonic acid or diethyl undec-<NUM>-enyl phosphonate, for example, as per Ruiterkamp, G. et al, "Surface functionalization of titanium dioxide nanoparticles with alkanephosphonic acids for transparent nanocomposites", Journal of Nanoparticle Research, <NUM> (<NUM>) <NUM> (block <NUM>). The functionalized particles are then blended with polyethylene, either pure or containing small amounts of initiators, and melt extruded to form a thin film with average thickness of <NUM> microns (block <NUM>). In some instances, pressing is required to thin or densify the film (block <NUM>). The film is then briefly etched, for example with oxygen plasma or UV-ozone, to remove residual organic material from the surfaces of the LLTO (block <NUM>).

<FIG> illustrates a second process <NUM> to form a second variant of the ceramic-polymer electrolyte <NUM> of <FIG>. In the second process <NUM>, single crystals of lithium lanthanum zirconium oxide ("LLZO") are grown with an average crystal size of <NUM> microns (block <NUM>). These particles are placed in a fluidized bed reactor and <NUM> of amorphous silicon dioxide ("SiO<NUM>") is deposited by a vapor-phase process, such as sputtering, onto the surface of the LLZO (block <NUM>). After deposition, the particles are briefly annealed to homogenize the interface (block <NUM>). The particles are then coated with <NUM>-methacryloxypropyl trimethoxysilane via hydrolysis (block <NUM>). The coated particles are then arranged in a single layer via contact with a surface coated in a water-soluble adhesive (block <NUM>). The surface is then coated with a layer of ultraviolet (UV)-curable acrylate monomer and the entire assembly is UV cured (block <NUM>). The water soluble adhesive is then removed (block <NUM>). In some instances, the remaining film is briefly etched, for example with reactive-ion etching (RIE) or hydrogen fluoride (HF) etching combined with oxygen plasma or UV-ozone, to remove residual organic material and silica, thereby exposing the surfaces of the LLZO (block <NUM>).

<FIG> illustrates a third process <NUM> to form a third variant of the ceramic-polymer electrolyte <NUM> of <FIG>. In the third process <NUM>, particles of amorphous <NUM>/<NUM> mol% Li<NUM>S-P<NUM>S<NUM> are prepared with an average particle size of <NUM> microns (block <NUM>). These particles are placed in a fluidized bed reactor and <NUM> of SiO<NUM> is deposited by a vapor-phase process, such as sputtering, onto the surface of the Li<NUM>S-P<NUM>S<NUM> (block <NUM>). The particles are then reacted with a trimethoxysilane-substituted polystyrene or sulfonate-substituted polystyrene in an anhydrous liquid phase or by polystyrene grafting (block <NUM>). The reacted particles are then blended in an appropriate ratio with a polystyrene solution and cast out to form a film with an average thickness of <NUM> microns (block <NUM>). In some instances, pressing is required to thin or densify the film (block <NUM>). The film is then etched lightly, for example by RIE, to remove excess polymer and SiO<NUM>, thereby exposing the sulfide surface on both sides of the thin film (block <NUM>).

<FIG> illustrates a fourth process <NUM> to form a fourth variant of the ceramic-polymer electrolyte <NUM> of <FIG>. In the fourth process <NUM>, particles of lithium aluminum titanium silicon phosphate ("LATSP"), a Li-conducting glass ceramic ("LICGC"), are prepared with an average particle size of <NUM> microns (block <NUM>). These particles are wet-coated with SiO<NUM> via a typical sol-gel process (block <NUM>). A polysiloxane with trichloro- or trimethoxy-silane pendant groups is grafted onto the SiO<NUM> coated surface of the particles via hydrolysis (block <NUM>). The composite is then blade cast into a film with an average dried thickness of <NUM> microns (block <NUM>). In some instances, pressing is required to thin or densify the film (block <NUM>). The film is then etched lightly, for example by RIE, to remove excess polymer and SiO<NUM>, thereby exposing the LATSP surface on both sides of the thin film (block <NUM>).

The composite electrolyte disclosed herein as well as batteries and devices which include the composite electrolyte can be embodied in a number of different types and configurations.

The composite electrolyte contains at least one ion-conducting inorganic phase and at least one non-conducting organic phase. The primary inorganic ion-conducting phase is composed of particles or structures that traverse the entire thickness of the electrolyte, and the interfaces between different materials in the composite membrane possess strong adhesion characteristics.

The composite electrolyte may form a membrane that possesses an average ionic conductivity of at least 1E-<NUM>/cm, or area-specific resistance below <NUM> ohm-cm2 (preferably < <NUM> ohm-cm2).

The strong adhesion at the interfaces between the different materials in the composite electrolyte is achieved via use of an unbroken chain of ionic or covalent bonds.

The strong adhesion at the interfaces between the different materials in the composite electrolyte is achieved via adhesion promoters or other surface modification agents.

The composite electrolyte may be stable against, or may form a stable solid electrolyte interface (SEI) against, Li metal.

The composite electrolyte may form a free-standing, flexible film.

The composite electrolyte may prevent or hinder passage of solvents or salts.

The composite electrolyte may have a transference number t+ of greater than <NUM>.

The composite electrolyte may be resistant to Li dendrite penetration at current densities of at least <NUM> mA/cm2.

The battery contains a composite electrolyte with at least one ion-conducting inorganic phase and at least one non-conducting organic phase. The primary inorganic ion-conducting phase is composed of particles or structures that traverse the entire thickness of the electrolyte, and the interfaces between different materials in the composite membrane possess strong adhesion characteristics.

The composite electrolyte may function to suppress lithium dendrites.

The composite electrolyte may function to isolate otherwise solvents, salts, or other mobile materials on one or more of the anode side and the cathode side of the cell.

Claim 1:
A composite electrolyte structure, comprising:
a first side and a second side defining a thickness;
a non-conducting organic phase portion extending from the first side to the second side; and
a plurality of ion-conducting inorganic phase structures dispersed throughout the non-conducting organic phase portion, each of the plurality of ion-conducting inorganic phase structures spanning the thickness such that a first portion of each of the plurality of ion-conducting inorganic phase structures is exposed on the first side and a second portion of each of the plurality of ion-conducting inorganic phase structures is exposed on the second side, each of the plurality of ion-conducting inorganic phase structures defining a respective interface with the non-conducting organic phase portion, wherein each of the respective interfaces includes an unbroken chain of at least one of ionic bonds and covalent bonds so as to firmly adhere the non-conducting organic phase portion to each of the plurality of ion-conducting inorganic phase structures,
wherein each of the plurality of ion-conducting inorganic phase structures is formed from a monocrystalline material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second layer of a second adhesion promoter disposed on the first layer, or
wherein each of the plurality of ion-conducting inorganic phase structures is formed from an amorphous material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second adhesion promoter reacted with the first layer, or
wherein each of the plurality of ion-conducting inorganic phase structures is formed from a glass ceramic material, the structures each including a first layer of a first adhesion promoter disposed on a surface of the structure and a second adhesion promoter grafted on the first layer.