Lithium conductive ceramic oxide decontamination method

Abstract

The present invention relates to a method for decontaminating a lithium conductive ceramic oxide material. The method comprises soaking a lithium conductive ceramic oxide material having a first thickness of surface contaminants in a first organic solvent containing an inorganic salt at an inorganic salt concentration to obtain a soaked lithium conductive ceramic oxide material. The method further comprises rinsing the soaked lithium conductive ceramic oxide material in a second organic solvent to obtain a decontaminated lithium conductive ceramic oxide material having a second thickness of surface contaminants that is less than the first thickness of surface contaminants.

Description

Technical Field

[0001] The present disclosure relates to lithium conductive ceramic oxide decontamination methods and decontaminated lithium conductive ceramic oxide materials, and in some embodiments, to the use of such materials as solid state electrolytes (SSEs) with improved interfacial properties. Background Art

[0002] Shows greater than 10mScm at room temperature -1 Li + Conductive solid electrolyte (SSE) systems have shown promise in applying lithium metal anodes to batteries with high energy and power densities. Such applications can offer several advantages over conventional liquid electrolyte systems. Non-limiting examples of these benefits include higher gravimetric and volumetric energy densities, wider operable voltages, wider temperature ranges, and improved safety. However, many obstacles remain for implementing such SSE systems with lithium metal anodes in such applications. Summary of the Invention

[0003] According to one embodiment, a method for decontaminating a lithium conductive ceramic oxide material is disclosed. The method includes soaking a lithium conductive ceramic oxide material having a first thickness of surface contaminants in a first organic solvent containing an inorganic salt at an inorganic salt concentration to obtain a soaked lithium conductive ceramic oxide material. The method further includes rinsing the soaked lithium conductive ceramic oxide material in a second organic solvent to obtain a decontaminated lithium conductive ceramic oxide material having a second thickness of surface contaminants that is less than the first thickness of surface contaminants. The first thickness can be any one of the following values ​​or a range of any two of the following values: 50, 55, 60, 65, and 70 nm. The second thickness can be any one of the following values ​​or a range of any two of the following values: 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 3.0, 4.0, and 5.0 nm.

[0004] According to another embodiment, a method of forming a solid electrolyte material is disclosed. The method includes soaking a lithium conductive ceramic oxide material having a first thickness of surface contaminants in a first organic solvent containing an inorganic salt at an inorganic salt concentration to obtain a soaked lithium conductive ceramic oxide material. The method further includes rinsing the soaked lithium conductive ceramic oxide material in a second organic solvent to obtain a decontaminated lithium conductive ceramic oxide material having a second thickness of surface contaminants that is less than the first thickness of surface contaminants. The method also includes drying the decontaminated lithium conductive ceramic oxide material to obtain a dried, decontaminated lithium conductive ceramic oxide material. The method also includes mixing the dried, decontaminated lithium conductive ceramic oxide material with a polymer material to form the solid electrolyte material.

[0005] In yet another embodiment, a thin film solid electrolyte material is disclosed. The thin film solid electrolyte material comprises a decontaminated lithium conductive ceramic oxide material including a surface thickness of bicarbonate less than 5.0 nm. The thin film solid electrolyte material further comprises a polymer material. The thin film solid electrolyte material has a thickness less than 100 μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of a solid-state battery (SSB) according to one embodiment.

[0007] Figure 2 According to one embodiment, a method for obtaining a + Schematic diagram of the steps in the method for removing surface contamination from conductive ceramic oxides.

[0008] 3a, 3b, 3c, and 3d show graphs of soft X-ray absorption spectra (XAS) of LLZO powders under different conditions.

[0009] Figure 4 Depicted are representative Nyquist plots of Li / LLZO / Li cells at room temperature before and after treatment according to one embodiment.

[0010] Figure 5 Depicts the flow of a 1.4 μA cm-1 ion stream before and after treatment according to one embodiment. -2 Figure 2 shows the current density of Li / LLZO / Li cells during galvanostatic cycling at room temperature. DETAILED DESCRIPTION

[0011] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take different and alternative forms. The drawings are not necessarily to scale; certain features may be enlarged or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but should merely serve as a representative basis for teaching those skilled in the art to use various embodiments differently. As will be understood by those of ordinary skill in the art, the various features illustrated and described with reference to any one of the accompanying drawings may be combined with features illustrated in one or more other drawings to produce embodiments that are not explicitly illustrated or described. The combination of illustrated features provides representative embodiments of typical applications. However, for specific applications or implementations, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired.

[0012] Except in the examples, or where otherwise expressly indicated, all numerical quantities in this specification indicating amounts of materials or conditions of reaction and / or use should be understood as modified by the word "about" when describing the broadest scope of the invention. Practice within the stated numerical ranges is generally preferred. Similarly, unless expressly indicated to the contrary: percentages, "parts," and ratios are by weight; the term "polymer" includes "oligomers," "copolymers," "terpolymers," and the like; description of a group or class of materials as suitable or preferred for a given purpose in connection with the present invention means that mixtures of any two or more members of that group or class are also suitable or preferred; molecular weights given for any polymer refer to number-average molecular weights; components described in chemical terms refer to the components when added to any combination specified in the specification and do not necessarily exclude chemical interactions between the components of the mixture once mixed; the first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and applies mutatis mutandis to conventional grammatical variations of the initially defined abbreviation; and, unless expressly indicated to the contrary, measurements of properties are determined by the same techniques as previously or subsequently cited for the same property.

[0013] The present invention is not limited to the specific embodiments and methods described below, as specific components and / or conditions may of course vary. Furthermore, the terminology used herein is used only for the purpose of describing specific embodiments of the present invention and is not intended to be limiting in any way.

[0014] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to an element in the singular is intended to include a plurality of elements.

[0015] The terms "substantially" or "approximately" may be used herein to describe the disclosed or claimed embodiments. The terms "substantially" or "approximately" may modify a value or relative characteristic disclosed or claimed in this disclosure. In this case, "substantially" or "approximately" may mean that the value or relative characteristic it modifies is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 10% of that value or relative characteristic.

[0016] At a cost of less than $100 per kWh -1 With more than 500Whkg -1 or 1,000WhL -1 The use of lithium metal anodes in solid-state batteries (SSBs) with energy densities greater than 10 mS cm at room temperature is currently not feasible. -1 Li+ conductivity, thus meeting these performance levels. One material that shows promise in achieving this conductivity is Li7La3Zr2O 12 Garnet-type ceramic oxides (also known as LLZO) are a prime candidate for this application because they possess (1) fast lithium-ion conductivity, (2) reduced flammability, (3) sufficient mechanical strength (e.g., an elastic modulus of at least 150 GPa and a fracture toughness of 0.86-1.63 MPa m), (4) a wide electrochemical window (e.g., 6 V or higher), and (5) chemical stability with metallic Li. Despite these promising properties, the use of ceramic oxides (including LLZO) in high-performance SSBs has been largely unsuccessful. One of the major obstacles to such success is the large interfacial impedance between the ceramic oxide and the electrode material.

[0017] Unlike many traditional ceramic oxides (such as La2O3, Al2O3 and ZrO2), LLZO and other Li + Conductive ceramic oxides require great care during handling and storage due to their high reactivity. During wet processing, Li + Conductive ceramic oxides react with the solvent and produce adventitious carbon. Similarly, during storage, Li + Conductive ceramic oxides act as surface contaminants in Li + Thick layers of ion-isolating materials (e.g., carbonates, hydroxides, etc.) on the surface of the conductive ceramic oxide. The formation of these layers is one of the main reasons for the interfacial resistance between LLZO and Li metal. In addition, the formation of these layers may cause the Li metal and Li + The contact area between the conductive ceramic oxides is drastically reduced.

[0018] Current recommendations exist for cleaning surface contaminated Li +Surfaces of conductive ceramic oxides such as LLZO. Several surface finishing methods have been proposed to decontaminate LLZO surfaces. One finishing method is dry polishing (DP), while another is wet polishing (WP). DP can involve manually dry polishing the LLZO with sandpaper of a certain abrasive grit size. The abrasive grit size can be any one of the following values ​​or a range of any two of the following values: 400, 600, and 1200. WP can involve wet polishing the LLZO with a glycol-based polishing slurry using an automated polishing machine with diamond polishing abrasives. Following this step, the LLZO is washed with alcohol to remove residual polishing slurry from the surface. However, these WP and DP methods are not suitable for relatively thin (e.g., 10-40 μm) Li+ conductive ceramic oxides because they damage the oxide material. Post-heat treatment (e.g., at temperatures in the 400-700°C range) can also be used to decompose surface contaminants. However, in many cases, the surface contaminant layer simply reforms during cooling. As another disadvantage, these processes are also energy intensive. As another suggestion, surface modification or coating with Au or Al2O3 has been tried. Another suggestion is to react LLZO with carbon at 700°C. However, these methods are not scalable and add additional processing steps. In addition, if the coating does not maintain its integrity during cycling, the cycle life may be compromised.

[0019] However, given these challenges, much work continues to demonstrate that the room temperature is greater than 10 mS cm -1 Li + The field of SSE systems with high conductivity is being explored to implement lithium metal anodes in batteries with high energy and power density. However, many fundamental issues and major engineering challenges remain to realize the potential of these applications, especially in the field of electrochemical interfaces. + The surface chemistry of conductive ceramic oxides controls the interfacial resistance and Li wettability. Typically, in SSBs, low interfacial resistance relative to liquid electrolytes is achieved through complex surface modifications or using laborious post-sintering methods or mechanical milling. What is needed is a treatment method that significantly reduces Li ions by removing surface contaminants. + Interfacial resistance between conductive ceramic oxide and Li metal.

[0020] In one or more embodiments, a method is disclosed to reduce Li + The interface resistance between the conductive ceramic oxide layer and the Li metal is reduced. In addition, ceramic oxide materials with a surface having reduced interface resistance are disclosed. These methods and materials can increase Li wettability and achieve lower interface resistance between Li and ceramic oxide layers such as LLZO. In one aspect, wettability can be improved by increasing the surface resistance of Li metal. +The contact angle of wetting of molten Li on a conductive ceramic oxide, such as LLZO, is measured. Acceptable wettability can be indicated by one of the following contact angles or in the range of any two of the following contact angles: 40°, 50°, 60°, 70°, 80°, 90°, and 100°. In one aspect, the interfacial resistance can be determined by electrochemical impedance spectroscopy. Acceptable lower interfacial resistance can be any one of the following or in the range of any two of the following: 0, 5, 10, 15, and 20 Ohm cm 2 .

[0021] Figure 1 is a schematic diagram of an SSB 10 according to one embodiment. SSB 10 includes a cathode 12, an electrolyte 14, an anode 16, a negative current collector 18, and a positive current collector 20. Electrolyte 14 is configured to function as an ion conductor and a separator. Cathode 12 and anode 16 contact opposite surfaces of electrolyte 14. Negative current collector 18 contacts the surface of anode 16 opposite the surface of anode 16 contacting electrolyte 14. Positive current collector 18 contacts the surface of cathode 12 opposite the surface of cathode 12 contacting electrolyte 14. SSB 10 is connected to an electrical load 22 via conductors 24 and 26. Conductor 24 connects negative current collector 18 to electrical load 22. Conductor 26 connects positive current collector 20 to electrical load 22.

[0022] Anode 16 may be formed of Li metal. Other non-limiting materials that can be used as anode 16 include carbon, titanate, and lithium alloys. Electrolyte 14 may be formed of Li + Conductive ceramic oxides such as LLZO are formed. + Other non-limiting examples of conductive ceramic oxides include Li5La3Ta2O 12 (LLTO), Li6La2CaTa2O 12 (LLCTO), Li6La2ANb2O 12 (A=Ca, Sr), Li 1+x Al x Ge 2-x (PO4)3(LAGP), Li 14 Al 0.4 (Ge 2-x Ti x ) 1.6 (PO4)3(LAGTP), perovskite Li 3x La2 / 3-x TiO3(LLTO), Li 0.8 La 0.6 Zr2(PO4)3(LLZP), Li 1+x Ti 2-x Al x(PO4)3(LTAP), Li 1+x+y Ti 2-x Al x Si y (PO4) 3-y (LTASP), LiTi x Zr 2-× (PO4)3(LTZP), Li2Nd3TeSbO 12 and mixtures thereof. The cathode 12 may be made of a Li-based oxide material such as lithium cobalt oxide (LiCoO2) (LCO), lithium manganese oxide (LiMn2O4) (LMO), lithium nickel manganese cobalt oxide (LiNiMnCoO2) (NMC), lithium iron phosphate (LiFePO4) (LIP), lithium nickel cobalt aluminum oxide (LiNiCoAlO2) (NCA), lithium titanate (Li4Ti5O 12 )(LT), and mixtures thereof. The cathode 12 may have a lattice structure. The negative electrode current collector 18 may be formed of a single substance or alloy metal material, such as copper or a copper alloy. The positive electrode current collector 18 may be formed of a single substance or alloy material, such as aluminum or an aluminum alloy.

[0023] During charging of the SSB 10, Li ions are deintercalated from the lattice structure of the cathode 12 and transferred to the anode 16 through the ion-conducting solid electrolyte 14, while electrons are transferred to the anode 16 through the external circuit 28 (which includes the conductors 24 and 26 and the electrical load 22). During discharge, as shown in FIG. Figure 1 As shown in FIG, lithium ions are deintercalated from the anode 16 and transferred to the cathode 12 through the solid electrolyte 14, while electrons pass through the external circuit 28 and drive the electrical load 22 to work. Several reaction steps are involved at the interface between the electrolyte 14 and the cathode 12 and the electrolyte 14 and the anode 16. First, Li ions diffuse in the electrolyte 14. Second, Li ions are adsorbed on the surface of the cathode 12 or the anode 16. Third, charge transfer occurs. Fourth, intercalation occurs in the cathode 12 or the anode 16. Fifth, Li ions diffuse into the cathode 12 or the anode 16. In addition, surface reactions occur between the electrolyte 14 and the cathode 12 and between the electrolyte 14 and the anode 16.

[0024] In one or more embodiments, a method for recovering Li2O3 from a SSE in a SSB is disclosed. + Methods for removing surface contamination from conductive ceramic oxides such as LLZO. Figure 2 According to one embodiment, a method for obtaining a + Schematic diagram of the steps of the method for removing surface contamination 29 from conductive ceramic oxide powder material 34 and thin film material 36. +The conductive ceramic oxide powder material 34 may be spherical particles having a diameter that is one of the following values ​​or within a range of any two of the following values: 400, 450, 500, 550, and 600 nm.

[0025] In Li + In the surface region of the conductive ceramic oxide powder material 34, the Li + The thickness of the surface contamination material on the conductive ceramic oxide powder material 34 may be one of the following values ​​or in a range of any two of the following values: 50, 55, 60, 65, and 70 nm. + In the surface region of the conductive ceramic oxide thin film material 36, the Li + The thickness of the surface contamination material on the conductive ceramic oxide thin film material 36 can be one of the following values ​​or in a range of any two of the following values: 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 200 nm, and 2 μm nm. In one embodiment, a planar 40 μm LLZO film can have the following amounts of Li2CO3 surface contamination by weight, based on the thickness of the Li2CO3 surface contamination: 0.2 wt% (200 nm) and 2 wt% (2 μm).

[0026] In one embodiment, Figure 2 As shown by arrows 30 and 32 on the left, the method includes soaking Li in an organic solvent having a salt at a predetermined temperature. + The first step is to add a conductive ceramic oxide material for a predetermined amount of time. +The conductive ceramic oxide material can be impregnated in various forms, including but not limited to powder form 34 or film form 36, wherein the film is formed as used in SSB. The thickness of the film can be any one of the following values ​​or in the range of any two of the following values: 20, 30, 40, 50, and 60 μm. Non-limiting examples of organic solvents that can be used in one or more embodiments include tetrahydrofuran (THF) or 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrakis(ethylene glycol) dimethyl ether (TEGDME), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethyl propyl ether (EPE), diethyl carbonate (DEC), fluorinated cyclic carbonates (F-AEC), fluorinated linear carbonates (F-EMC), fluorinated ethers (F-EPE), THF, glymes, and mixtures thereof. Non-limiting examples of salts that can be used in one or more embodiments include LiBF4, LiPF6, LiBC4O8 (LiBOB), LiPF3(CF2CF3)3 (LiFAP), LiBr, LiCl, LiI, LiClO4, LiFSI, LiNO3, LiPO2F2, Li(CF3SO2)2N (LiTFSI), LiCF3SO3, LiC(CF3SO2)3, LiAsF6, LiN(SO2CF2CF3)2 (LiBETI), and mixtures thereof. The concentration of the salt in the organic solvent can be any one of the following values ​​or a range of any two of the following values: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, and 1.2 M. The predetermined amount of time can be any one of the following values ​​or a range of any two of the following values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 hours. The predetermined temperature can be any one of the following values ​​or a range of any two of the following values: 20, 30, 40, 50, and 60°C.

[0027] In one embodiment, the method comprises rinsing the Li +The second step of the conductive ceramic oxide material for a predetermined amount of time. Non-limiting examples of organic solvents that can be used in one or more embodiments include tetrahydrofuran (THF), 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrakis(ethylene glycol) dimethyl ether (TEGDME), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethyl propyl ether (EPE), diethyl carbonate (DEC), fluorinated cyclic carbonate (F-AEC), fluorinated linear carbonate (F-EMC), fluorinated ether (F-EPE), THF, glycol dimethyl ethers / polyethylene ethers (glymes), and mixtures thereof. The predetermined amount of time can be any one of the following values ​​or a range of any two of the following values: 5, 10, 15, 20, 25, and 30 minutes. Li + Conductive ceramic oxide powder material 34 and thin film material 36 may be placed in compartments 38 and 40 , respectively, for a rinsing step.

[0028] In one embodiment, the method comprises drying the Li + The third step is to use conductive ceramic oxide materials. For example, Li + The conductive ceramic oxide material may be dried in a vacuum condition for a predetermined amount of time. The predetermined amount of time may be any one of the following values ​​or a range of any two of the following values: 60, 70, 80, 90, 100, 110, and 120 minutes. + Conductive ceramic oxide powder material 34 and thin film material 36 may be placed in compartment 38 or 40, respectively, for a drying step. Compartments 38 and 40 may be maintained under vacuum conditions.

[0029] In the case of Li + After the rinsing and drying steps 42 and 44 of the conductive ceramic oxide powder material 34 and the thin film material 36, these materials are decontaminated from surface contamination. + In the surface region of the conductive ceramic oxide powder material 34, the Li + The thickness of the surface contamination material on the conductive ceramic oxide powder material 34 may be one of the following values ​​or a range of any two of the following values: 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 3.0, 4.0, 5.0, and 20.0 nm. + In the surface region of the conductive ceramic oxide thin film material 36, the Li +The thickness of the surface contamination material on the conductive ceramic oxide thin film material 36 may be one of the following values ​​or a range of any two of the following values: 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 3.0, 4.0, 5.0, and 20.0 nm. In one embodiment, a planar 40 μm LLZO film may have the following amount of Li2CO3 surface contamination by weight, based on the thickness of the Li2CO3 surface contamination: 2.1×10 -3 In one embodiment, a spherical 500 nm diameter LLZO particle will have the following amounts of Li2CO3 surface contamination by weight, based on the thickness of the Li2CO3 surface contamination: 0.47 wt% (2 nm) and 5.16 wt% (20 nm).

[0030] Figures 3a, 3b, 3c, and 3d show graphs 50, 100, 150, and 200 of soft X-ray absorption spectra (XAS) of LLZO powders under different conditions. As described below, these soft XAS spectra show that the LLZO powders treated with the methods disclosed in one or more embodiments significantly reduce the presence of surface contaminants (e.g., Li2CO3).

[0031] Figure 50 depicts the O K-edge (5nm) spectrum by plotting the intensity (au) as a function of energy (eV) for LLZO powder under different conditions. Curve 52 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in a dry room for six (6) months. Curve 54 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in ambient air for three (3) days. Curve 56 depicts the intensity (au) as a function of energy (eV) for LLZO powder treated using a treatment method of one embodiment, wherein after three (3) days of air exposure, the LLZO powder is immersed in a solution of ethylene carbonate and dimethyl carbonate with LiBF4 salt for 16 hours. For comparison with curves 52, 54 and 56, curve 58 depicts the intensity (au) as a function of energy (eV) for pure Li2CO3. The reduction in intensity (au) as a function of energy (eV) is a result of removing carbonates from the LLZO powder. In region 60 of Figure 50, at approximately 539 eV, the pure Li2CO3 curve 58 has the highest intensity peak 64, which is similar to the peak of LLZO stored in air for three days, curve 54. The treated LLZO powder curve 56 has the lowest intensity peak 66 (based on the height of the peak compared to the baseline). In region 62 of Figure 50, at approximately 543 eV, the pure Li2CO3 curve 58 has the highest intensity peak 68, while the treated LLZO powder curve 56 has a relatively lower intensity peak. These decreases in relative intensity support that the treatment method significantly reduces carbonate contamination on the treated LLZO powder, in contrast to the carbonate layer formed on the surface of the LLZO powder according to curves 52 and 54.

[0032] Figure 100 depicts the O K-edge (50nm) spectrum by plotting the intensity (au) as a function of energy (eV) for LLZO powder under different conditions. Curve 102 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in a dry room for six (6) months. Curve 104 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in ambient air for three (3) days. Curve 106 depicts the intensity (au) as a function of energy (eV) for LLZO powder treated using the treatment method determined in connection with the example shown in Figure 3a after three (3) days of air exposure. For comparison with curves 102, 104 and 106, curve 108 depicts the intensity (au) as a function of energy (eV) for pure Li2CO3. The peak marked with an arrow pointing downward decreases when the sample is treated according to one or more embodiments. These peaks are associated with Li2CO3, as shown by the reference measurement with only Li2CO3.Thus, treatment according to one or more embodiments removes Li2CO3.

[0033] Figure 150 depicts the La M-edge (5 nm) spectrum by plotting the intensity (au) as a function of energy (eV) for LLZO powders under different conditions. Curve 152 depicts the intensity (au) as a function of energy (eV) for LLZO powders stored in a dry room for six (6) months. Curve 154 depicts the intensity (au) as a function of energy (eV) for LLZO powders stored in ambient air for three (3) days. Curve 156 depicts the intensity (au) as a function of energy (eV) for LLZO powders treated using the treatment method determined in connection with the example shown in Figure 3a after three (3) days of air exposure. In region 158 of graph 150, at approximately 851 eV, peak 160 of the LLZO powder curve 154 stored in air for three (3) days and peak 162 of the LLZO powder curve 152 stored in a dry room each have a different peak that differs by at least 0.7 au from peak 164 of the treated LLZO powder curve 156. This variation supports that carbonate formation on the treated LLZO powder is significantly reduced by the treatment method of one or more embodiments.

[0034] Figure 200 depicts the C K-edge (5 nm) spectrum by plotting the intensity (au) as a function of energy (eV) for LLZO powder under different conditions. Curve 202 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in a dry room for six (6) months. Curve 204 depicts the intensity (au) as a function of energy (eV) for LLZO powder stored in ambient air for three (3) days. Curve 206 depicts the intensity (au) as a function of energy (eV) for LLZO powder treated using the treatment method determined in connection with the example shown in Figure 3a after three (3) days of air exposure. For comparison with curves 202, 204 and 206, curve 208 depicts the intensity (au) as a function of energy (eV) for pure Li2CO3. When the sample is treated according to one or more embodiments, the peak decreases. These peaks are associated with Li2CO3, as shown by the reference measurement with only Li2CO3.Thus, treatment according to one or more embodiments removes Li2CO3.

[0035] In a further example, the electrochemical cycling stability and interfacial resistance of LLZO particles with and without the treatment methods described in connection with the examples in Figures 3a-3d were tested using lithium plating and stripping methods and electrochemical impedance spectroscopy (EIS). In one example, the LLZO particles were cylindrical particles with a thickness of 0.2 cm and an electrode area of ​​11.3 cm. 2 At room temperature, EIS testing was used to measure the contribution to the impedance of washed and unwashed particles of LLZO. The results of this test are shown in Figure 4 middle. Figure 4 Representative Nyquist plots of Li / LLZO / Li cells at room temperature before and after treatment are shown. Figure 4 Graph 250 plots -lm (Z) Ohm as a function of Re (Z) (Ohm) for the dry room: curve 252, and the treated: curve 254. Figure 4 As shown in , the treated pellets exhibited a 6.5-fold reduction in impedance in both the interface and bulk regions compared to the untreated sample. The reduction in impedance can be one of the following values ​​or a range of any two of the following values: 6, 8, 10, 12, 14, 16, 18, 20, and 22 times. The overall reduction in impedance is at least partially attributed to the removal of surface contaminants (e.g., Li2CO3) during treatment.

[0036] As a benefit of the treatment methods of one or more embodiments, the conformal contact of the Li metal on the LLZO surface is increased, thereby increasing the effective ion transfer area and the transport of ions between the LLZO and the Li. DC lithium plating and stripping experiments were conducted to evaluate the impedance and Li ion transport capacity across the LLZO and Li metal interface. Figure 5 The results of the experiment are shown in Figure 2. -2 The current density of Li / LLZO / Li cells at room temperature is shown in the galvanostatic cycling diagram. -2 After 75 hours at a current density of 100 nm, the treated particles stabilized at approximately 0.03 volts, as shown in region 302, while the untreated sample showed a noisy potential response with large voltage polarization, as shown in regions 304 and 306, which demonstrates uneven ion transport through the interface. The treatment methods of one or more embodiments significantly reduce contamination to minimize or eliminate the large interfacial impedance between LLZO (and other lithium-conductive ceramic oxides) and Li in SSBs.

[0037] Although exemplary embodiments have been described above, it is not intended that these embodiments describe all possible forms covered by the claims. The words used in the specification are descriptive rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As previously mentioned, the features of the various embodiments can be combined to form further embodiments of the present invention, which may not be explicitly described or illustrated. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations in terms of one or more desired characteristics, those skilled in the art recognize that one or more features or characteristics can be compromised in order to achieve the desired overall system characteristics, depending on the specific application and implementation. These characteristics may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, to the extent that any embodiment is described as being less desirable than other embodiments or prior art implementations in terms of one or more characteristics, these embodiments do not exceed the scope of the disclosure and may be desirable for a particular application.

Claims

1. A method for decontaminating a lithium conductive ceramic oxide material, the method comprising: soaking the lithium conductive ceramic oxide material having surface contaminants of a first thickness in a first organic solvent comprising an inorganic salt at a concentration of 0.1-1.2 M to obtain a soaked lithium conductive ceramic oxide material; and rinsing the soaked lithium conductive ceramic oxide material in a second organic solvent to obtain a decontaminated lithium conductive ceramic oxide material having a second thickness of surface contaminants that is less than the first thickness of surface contaminants; wherein the first organic solvent is tetrahydrofuran (THF), 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrakis(ethylene glycol) dimethyl ether (TEGDME), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethyl propyl ether (EPE), diethyl carbonate (DEC), fluorinated cyclic carbonate (F-AEC), fluorinated linear carbonate (F-EMC), fluorinated ether (F-EPE), THF, glymes / polyethylene ethers (glymes) or mixtures thereof; and The inorganic salt is LiBF4, LiPF6, LiBC4O8 (LiBOB), LiPF3(CF2CF3)3 (LiFAP), LiBr, LiCl, LiI, LiClO4, LiFSI, LiNO3, LiPO2F2, Li(CF3SO2)2N (LiTFSI), LiCF3SO3, LiC(CF3SO2)3, LiAsF6, LiN(SO2CF2CF3)2 (LiBETI) or a mixture thereof.

2. The method of claim 1, wherein the second thickness is at least 90% less than the first thickness.

3. The method of claim 1, wherein the surface contaminants comprise one or more carbonate compounds.

4. The method of claim 3, wherein the one or more carbonate compounds comprises Li2CO3.

5. The method of claim 1, wherein the lithium conductive ceramic oxide material is Li7La3Zr2O 12 (LLZO).

6. The method of claim 1, further comprising drying the decontaminated lithium conductive ceramic oxide material.

7. The method of claim 6, wherein the drying step comprises vacuum drying the decontaminated lithium conductive ceramic oxide material.

8. The method of claim 1, wherein the lithium conductive ceramic oxide material is Li7La3Zr2O 12 (LLZO), Li5La3Ta2O 12 (LLTO) or Li6La2CaTa2O 12 (LLCTO) or Li6La2ANb2O 12 (A=Ca, Sr) or Li 1+x Al x Ge 2-x (PO4)3(LAGP) or Li 14 Al 0.4 (Ge 2-x Ti x ) 1.6 (PO4)3(LAGTP) or perovskite Li 3x La 2 / 3-x TiO3(LLTO) or Li 0.8 La 0.6 Zr2(PO4)3(LLZP) or Li 1+x Ti 2-x Al x (PO4)3(LTAP) or Li 1+x+y Ti 2-x Al x Si y (PO4) 3-y (LTASP) or LiTi x Zr 2-x (PO4)3(LTZP), Li2Nd3TeSbO 12 or a mixture thereof.

9. A method of forming a solid electrolyte material, the method comprising: soaking the lithium conductive ceramic oxide material having surface contaminants of a first thickness in a first organic solvent comprising an inorganic salt at a concentration of 0.1-1.2 M to obtain a soaked lithium conductive ceramic oxide material; rinsing the soaked lithium conductive ceramic oxide material in a second organic solvent to obtain a decontaminated lithium conductive ceramic oxide material having a second thickness of surface contaminants that is less than the first thickness of surface contaminants; drying the decontaminated lithium conductive ceramic oxide material to obtain a dried, decontaminated lithium conductive ceramic oxide material; and mixing the dried, decontaminated lithium conductive ceramic oxide material with a polymer material to form a solid electrolyte material; wherein the first organic solvent is tetrahydrofuran (THF), 1,3-dioxolane (DOL), dimethoxyethane (DME), tetrakis(ethylene glycol) dimethyl ether (TEGDME), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), ethyl propyl ether (EPE), diethyl carbonate (DEC), fluorinated cyclic carbonate (F-AEC), fluorinated linear carbonate (F-EMC), fluorinated ether (F-EPE), THF, glymes / polyethylene ethers (glymes) or mixtures thereof; and The inorganic salt is LiBF4, LiPF6, LiBC4O8 (LiBOB), LiPF3(CF2CF3)3 (LiFAP), LiBr, LiCl, LiI, LiClO4, LiFSI, LiNO3, LiPO2F2, Li(CF3SO2)2N (LiTFSI), LiCF3SO3, LiC(CF3SO2)3, LiAsF6, LiN(SO2CF2CF3)2 (LiBETI) or a mixture thereof.

10. The method of claim 9, wherein the polymer material is a ceramic polymer electrolyte material.

11. The method of claim 10, wherein the ceramic polymer electrolyte material is LLZO / polyethylene oxide (PEO).

12. The method of claim 9, wherein the first and second organic solvents are the same organic solvent.

13. The method of claim 9, wherein the first and second organic solvents are different organic solvents.

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