Battery including new component

Abstract

To provide a battery cell which comprises a synthetic metal oxide having acidity except superacidity on at least its surface and arranged within an anode and / or a cathode.SOLUTION: A battery cell has an anode or a cathode, including an acidified metal oxide (AMO) material which has monodisperse nano particle morphology preferably with a size of 20 nm or less, which has a pH level lower than 7 when suspended in a 5-wt% solution, and which has a Hammett function H0 more than -12 on at least its surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Cross-references to related cases This application claims the benefit of U.S. Provisional Patent Application No. 62 / 483,789, filed April 10, 2017, entitled "Mixed Acidified Metal Oxide Additive for Use in Battery Electrodes," U.S. Provisional Patent Application No. 62 / 507,655, filed May 17, 2017, entitled "Batteries Using Acidified Electrodes," and U.S. Provisional Patent Application No. 62 / 507,660, filed May 17, 2017, entitled "Batteries Using Novel Cathodes," which are incorporated by reference into this disclosure as if fully set forth herein at this time. The present disclosure is in the field of materials useful for chemical energy storage and power devices, such as, but not limited to, batteries. More specifically, the present disclosure relates to battery cells with cathodes and / or anodes comprising acidified metal oxide ("AMO") nanomaterials. [Background technology]

[0002] Metal oxides have oxygen bonded to the metal, m O x They are compounds with the general formula: They are found in nature but can also be artificially synthesized. In synthetic metal oxides, the synthesis method can have a wide range of effects on the surface properties, including their acid / base properties. Changes in the surface characteristics can alter the properties of the oxide, affecting things like its catalytic activity and electron mobility. However, the mechanisms by which surfaces control reactivity are not always well characterized or fully understood. For example, in photocatalysis, surface hydroxyl groups are thought to facilitate the transfer of electrons from the conduction band to chemisorbed oxygen molecules.

[0003] Despite the importance of surface properties, the metal oxide literature, both academic papers and patents, has focused primarily on creating novel nanoscale crystalline forms of metal oxides to improve energy storage and power applications. Metal oxide surface properties have been neglected, and outside of the chemical catalysis literature, very little innovation has been directed toward controlling or modifying the surfaces of known metal oxides to achieve performance goals.

[0004] The chemical catalysis literature has primarily focused on creating "superacids" that are more acidic than pure sulfuric acid (18.4 M H2SO4), which is often used for large-scale reactions such as hydrocarbon cracking. Superacidity cannot be measured on the conventional pH scale and is instead quantified by the Hammett number. The Hammett number (H0) can be thought of as extending the pH scale to negative numbers below zero. Pure sulfuric acid has an H0 of -12.

[0005] However, there are many reaction systems and applications where superacidity is too strong. For example, superacidity can degrade system components or catalyze undesirable side reactions. However, acidity can still be useful in these same applications because it provides enhanced reactivity and rate characteristics or enhanced electron mobility.

[0006] The battery literature teaches that acidic groups are detrimental to batteries, attacking metal current collectors and housings and potentially degrading other electrode components. Additionally, the prior art teaches that active catalytic electrode surfaces can lead to electrolyte decomposition, resulting in gas generation inside the cell and ultimately cell failure.

[0007] A need exists for a battery package having a synthetic metal oxide disposed within the anode and / or cathode that is acidic at least on its surface, but not super acidic. Summary of the Invention

[0008] This application describes materials corresponding to acidified metal oxides ("AMOs") and their uses in batteries, e.g., in battery electrode materials, catalysts, photovoltaic or photoactive components, and sensors. Techniques for making AMOs and devices comprising AMOs are further disclosed. The disclosed AMOs are optionally used in combination with acidic species to enhance their utility.

[0009] The described AMOs include those in the form of nanomaterials, such as nanoparticles, which can be monodisperse or substantially monodisperse, e.g., having a particle size of less than 100 nm. The disclosed AMOs, when suspended in water or resuspended in water after drying at certain concentrations (e.g., 5% by weight), exhibit a low pH, e.g., less than 7 (e.g., between 0 and 7), and further exhibit a Hammett function H0 greater than -12 (i.e., not superacidic), at least on the surface of the AMO.

[0010] The surface of the AMO may optionally be functionalized, such as with acidic or other electron-withdrawing species. Synthesis and surface functionalization may be accomplished in a "single-pot" hydrothermal method that functionalizes the surface of the metal oxide as it is synthesized from appropriate precursors. In some embodiments, this single-pot method does not require any additional acidification step or steps beyond those required to synthesize the metal oxide itself, resulting in an AMO material with the desired surface acidity (but not superacidic).

[0011] Optionally, surface functionalization is performed using strong electron-withdrawing groups ("EWGs") such as SO, PO, halogens (Br, Cl, etc.), alone or in combination with each other. Surface functionalization may also be performed with EWGs that are weaker than SO, PO, or halogens. For example, synthetic metal oxides may be surface functionalized with acetate (CHCOO), oxalate (CO), and citrate (CHO) groups.

[0012] Despite conventional wisdom that acidic species are undesirable in batteries because they can attack metal current collectors and housings, causing degradation of other electrode components, and active catalytic electrode surfaces can lead to electrolyte decomposition, gassing within the cell, and ultimately cell failure, the inventors have discovered that acidic species and components can be advantageous in batteries that use AMO materials in the battery electrodes.

[0013] For example, the combination or use of AMO with acidic species can improve the performance of the resulting material, system, or device, enhancing the device's capacity, cycling characteristics, and lifespan. As an example, batteries using AMO materials in combination with acidic electrolytes or electrolytes containing acidic species as described herein exhibit significant capacity increases, such as up to 100 mAh / g or more, over similar batteries using non-acidified electrolytes or electrolytes lacking acidic species. In some embodiments, improvements in capacity between 50 and 300 mAh / g can be achieved. Additionally, absolute capacities of up to 1000 mAh / g or more can be achieved using batteries with acidified electrolytes or electrolytes containing acidic species. Furthermore, the cycle life of batteries can be improved with the use of acidic electrolytes or electrolytes containing acidic species, such that the cycle life of batteries can be extended to up to 100 or more charge / discharge cycles.

[0014] Additionally or alternatively, batteries containing electrodes, such as cathodes or anodes, that are themselves acidic or contain acidic species, such as organic acids, may also be beneficial, again contrary to conventional teachings in battery technology. For example, batteries incorporating acidic electrodes or acidic species within electrodes may offer improved performance, capacity, cycling, and life, particularly when used with electrodes containing AMO materials. Capacity increases of up to 100 mAh / g or more can be achieved. Battery cycle life can also be improved by the use of acidic electrodes or electrodes containing acidic species, such as when the cycle life of the battery is extended by up to 100 cycles or more. As an example, an acidic electrode or an electrode containing acidic species may exhibit a pH of less than 7 (but not super acidic), such as when the electrode components are suspended in water (or resuspended in water after drying) at 5% by weight.

[0015] As a further example, batteries in which electrodes are formed using a slurry may also be beneficial and may run counter to conventional teachings in battery technology. As described herein, AMO materials may optionally be formed into battery electrodes by first forming a slurry of the AMO material with one or more binder compounds, solvents, additives (e.g., conductive or acidic additives), and / or other wet-processing materials. The slurry may be deposited onto a conductive material or current collector to form an electrode. Such slurries and / or solvents may optionally be acidic or include acidic species, which may again enable improved capacity, cycling characteristics, and lifespan of the resulting battery. Optionally, all or a portion of the solvent may be evaporated, leaving behind the AMO material, binder, additives, etc. The resulting material may optionally exhibit its own acidity, e.g., having a pH of less than 7 (but not super acidic) when suspended in water at 5 wt % (or resuspended in water after drying).

[0016] As noted above, the acidic species may optionally be included as an additive in any of the battery components, such as the electrodes or the electrolyte. Optionally, a battery including AMO may include an electrolyte disposed between the electrodes in which the acidic species is dissolved in a solvent. Such an electrolyte may also be referred to herein as an acidified electrolyte. The electrolyte may optionally include one or more lithium salts dissolved in a solvent, such as LiPF, LiAsF, LiClO, LiBF, LiCFSO, and combinations thereof. It will be understood that the electrolyte may be disposed in the space separating the electrodes (i.e., between the electrodes), as well as impregnating or permeating the pores of the electrodes and / or the pores of any material or structure optionally disposed between the electrodes, such as a separator.

[0017] Examples of acidic species useful with the AMOs, electrodes, and electrolytes described herein include, but are not limited to, organic acids such as carboxylic acids. Examples of acidic species include those that exhibit a pKa in water between -10 and 7, between -5 and 6, between 1 and 6, between 1.2 and 5.6, or about 4. Specific examples of organic acids include, for example, oxalic acid, carbonic acid, citric acid, maleic acid, methylmalonic acid, formic acid, glutaric acid, succinic acid, methylsuccinic acid, methylenesuccinic acid, citraconic acid, acetic acid, and benzoic acid. Examples of organic acids include dicarboxylic acids, such as

[0018] [ka] Formula (wherein R is a substituted or unsubstituted C1-C20 hydrocarbon, for example, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aromatic or heteroaromatic group, or a substituted or unsubstituted amine). Examples of organic acids include:

[0019] [ka] Formula (wherein L is a substituted or unsubstituted C1-C20 divalent hydrocarbon such as a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, or a substituted or unsubstituted amine). Examples of organic acids include organic acid anhydrides, for example

[0020] [ka] Formula (wherein R1 and R2 are independently a substituted or unsubstituted C1-C20 hydrocarbon, e.g., a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aromatic or heteroaromatic group, or a substituted or unsubstituted amine). Optionally, R1 and R2 can form a ring. Examples of organic acid anhydrides include any of the anhydrides of the organic acids listed above. Specific organic acid anhydrides include, but are not limited to, glutaric anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, and itaconic anhydride.

[0021] Useful concentrations of acidic species in either or both the electrolyte and the AMO electrode include 0 wt. % to 10 wt. %, 0.01 wt. % to 10 wt. %, 0.1 wt. % to 10 wt. %, 1 wt. % to 5 wt. %, or 3 wt. % to 5 wt. %.

[0022] Useful solvents include, for example, those used in lithium-ion battery systems, such as ethylene carbonate, butylene carbonate, propylene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, fluoroethylene carbonate, and mixtures thereof. Other useful solvents will be understood by those skilled in the art. Optionally, when an acidic species and a metal salt are dissolved in a solvent to form an electrolyte, the electrolyte itself exhibits acidic conditions (i.e., a pH of less than 7).

[0023] Examples of binders useful in the batteries and electrodes described herein include styrene butadiene copolymer (SBR), polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), acrylonitrile, polyacrylic acid (PAA), polyvinyl alcohol (PVA), polyamideimide (PAI), and any combination thereof. Optionally, conductive polymers may be useful as binders.

[0024] Other examples of additives useful in the AMOs and electrodes described herein include, but are not limited to, conductive additives. Examples of conductive additives include graphite, conductive carbon, carbon black, Ketjen black, and conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS), PEDOT:PSS composites, polyaniline (PANI), and polypyrrole (PPY). The conductive additive may be present in the electrode at any suitable concentration, such as, for example, from greater than 0 to as much as 35 wt %, 40 wt %, or more by weight. Optionally, the conductive additive is present in the electrode in the range of 1 wt% to 95 wt%, 1 wt% to 35 wt%, 1 wt% to 25 wt%, 5 wt% to 40 wt%, 10 wt% to 40 wt%, 15 wt% to 40 wt%, 20 wt% to 40 wt%, 25 wt% to 40 wt%, 30 wt% to 40 wt%, 35 wt% to 40 wt%, 40 wt% to 45 wt%, 40 wt% to 50 wt%, 40 wt% to 55 wt%, 40 wt% to 60 wt%, 40 wt% to 65 wt%, 40 wt% to 70 wt%, 40 wt% to 75 wt%, 40 wt% to 80 wt%, 40 wt% to 85 wt%, 40 wt% to 90 wt%, or 40 wt% to 95 wt%.

[0025] Also described herein are methods for fabricating batteries. An example method for fabricating a battery includes fabricating an AMO nanomaterial, forming a first electrode of or including an AMO nanomaterial, forming an electrolyte by dissolving one or more metal salts in a solvent, and disposing the electrolyte between the first electrode and a second electrode. Another example method for fabricating a battery includes fabricating an AMO nanomaterial, forming a first electrode of or including an AMO nanomaterial and one or more metal salts, and disposing the electrolyte between the first electrode and a second electrode.

[0026] Also disclosed herein are electrolytes for use in batteries. For example, the disclosed electrolytes are useful in batteries including a first electrode and a second electrode, such as a first electrode including an acidified metal oxide (AMO) nanomaterial. An example electrolyte includes a solvent and one or more metal salts dissolved in the solvent. Optionally, an acidic species, such as an acidic species different from the one or more metal salts, is dissolved in the solvent.

[0027] As described above, various acidic species are useful in the disclosed electrolytes, including organic acids and / or organic acid anhydrides. Examples of organic acids include, but are not limited to, oxalic acid, acetic acid, citric acid, maleic acid, methylmalonic acid, glutaric acid, succinic acid, methylsuccinic acid, methylenesuccinic acid, citraconic acid, or any combination thereof. Examples of organic acid anhydrides include, but are not limited to, glutaric anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, itaconic anhydride, or any combination thereof. Examples of other acidic species are described above. Useful acidic species include, but are not limited to, those exhibiting a pKa between -10 and 7, between -5 and 6, between 1 and 6, between 1.2 and 5.6, or about 4. The acidic species may optionally be present in the electrolyte at any suitable concentration, such as 0.01% to 10% by weight, 0.1% to 10% by weight, 1% to 5% by weight, or 3% to 5% by weight.

[0028] It will be appreciated that lithium metal salts such as LiPF6, LiAsF6, LiClO4, LiBF4, and LiCF3SO3 can be useful components of the disclosed acidified electrolytes. Examples of solvents include, but are not limited to, ethylene carbonate, butylene carbonate, propylene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, fluoroethylene carbonate, and mixtures thereof. Examples of solvents may be useful in metal ion batteries, such as lithium ion batteries. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a simplified cross-sectional view of an exemplary lithium-ion battery cell. [Figure 2] FIG. 2 is another simplified cross-sectional view of a lithium-ion battery cell in which the electrolyte is substantially contained by the separator. [Figure 3] FIG. 1 is a schematic diagram of a lithium-ion battery containing multiple cells. [Figure 4] 1 shows the difference in the cyclic voltammogram of AMO tin prepared by the methods disclosed herein compared to the cyclic voltammogram of commercially available non-AMO tin when cycled against Li. [Figure 5] The total reflectance of AMO tin oxide is shown to be different from that of commercial non-AMO tin oxide. [Figure 6]

[0023] Figure 1 shows X-ray photoelectron spectroscopy (XPS) data demonstrating surface functionalization inherently resulting from the synthesis methods disclosed herein. The values ​​shown are atomic concentrations in %. The rightmost column lists the corresponding pH of the synthesized nanoparticles measured when dispersed at 5 wt% in aqueous solution. [Figure 7] Electron microscopy images are provided showing the differences in morphology between AMO nanoparticles synthesized under identical conditions except for using different groups for functionalization. [Figure 8]The differences in morphology and performance of AMO nanoparticles synthesized under identical conditions but with two different total reaction times are shown. [Figure 9] Representative half-cell data are provided that demonstrate the difference in lithium behavior between spherical and elongated (needle-like or rod-like) AMOs upon cycling. [Figure 10] We provide X-ray photoelectron spectroscopy analysis of the surface of AMO nanoparticles synthesized using both strong (phosphorus-containing) and weak (acetate) electron-withdrawing groups, showing a higher atomic concentration of phosphorus than the bonds associated with acetate groups. [Figure 11A] Data are provided showing visible light activated degradation data of different AMOs. [Figure 11B] Data are provided showing UV light activated degradation data of different AMOs. [Figure 12] 1 is a graph comparing two AMOs, one with higher capacity for use in primary (single use) battery applications and the other with higher cycling capability for use in secondary (rechargeable) battery applications. [Figure 13] Charge / discharge capacity data and coulombic efficiency data are provided, demonstrating that AMO can improve battery performance without degradation of battery components or gassing. [Figure 14] Capacity and cycling data for AMO in standard, acidified, and basified electrolyte systems are shown. [Figure 15] Capacity and cycle data are shown for AMO and the same AMO where the acidification has been removed by solvent washing. [Figure 16] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 17] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 18]Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 19] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 20] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 21] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 22] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 23] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 24] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 25] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 26] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 27] Electron microscope images of the composite material are provided, as well as data including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling for battery cells including electrodes that include the composite material. [Figure 28] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 29] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 30] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 31] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 32] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 33] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 34] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 35]Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 36] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 37] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 38] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 39] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 40] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 41] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 42] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 43] Data is provided for battery cells containing electrodes including AMO materials, including plots of measured capacity versus cycle number and plots of voltage as a function of time during cycling. [Figure 44] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 45] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material. [Figure 46] Data are provided including electron microscope images of the AMO material, as well as plots of measured capacity versus cycle number and voltage as a function of time during cycling for battery cells containing electrodes comprising the AMO material.

[0030] definition For purposes of this disclosure, the following terms have the following meanings:

[0031] Acidic oxide - A term commonly used in the scientific literature to refer to binary compounds of nonmetallic elements and oxygen. An example is carbon dioxide, CO2. The oxides of some metalloids (e.g., Si, Te, Po) also have weakly acidic properties in the pure molecular state.

[0032] Acidified Metal Oxide ("AMO") - as used herein, refers to a binary compound of a metal element and oxygen that has been synthesized or modified to have a higher acidity than that of its natural mineralogical state, a Hammett function H > -12 (not super acidic), and an average particle size smaller than that of the natural mineralogical state. Naturally occurring mineralogical forms are not included within the scope of the AMO materials of the present invention. However, synthetic metal oxides that are more acidic than the most abundant naturally occurring (equivalent stoichiometric) mineralogical form, but are not super acidic, are included within the scope of the present disclosure and may be said to be AMO materials if they meet certain other conditions discussed in this disclosure.

[0033] Acidic - A term commonly used in the scientific literature to refer to compounds that have a pH of less than 7 in aqueous solution.

[0034] Electron-Withdrawing Group ("EWG") - An atomic or molecular group that attracts electron density to itself. The strength of an EWG is based on its known behavior in chemical reactions. For example, halogens are known to be strong EWGs. Organic acid groups, such as acetate, are known to be weakly electron-withdrawing.

[0035] Hammett function - an additional means of quantifying acidity in concentrated acidic solutions and superacids, where acidity is defined by the equation: H0 = pK BH+ +log([B] / [BH + On this scale, 18.4 moles of pure H2SO4 has an H0 value of -12. A value of H0 = -12 for pure sulfuric acid translates to a pH of -12. Instead, it is the acid species present that has a proton-adding capacity of 10 as measured by its ability to add a proton to a weak base. 12 H3O at a hypothetical (ideal) concentration in mol / L + This means that the acidity function has a protonation capacity equivalent to that of a superacid. The Hammett acidity function omits water in its equation. It is used herein to provide a quantitative means of distinguishing AMO materials from superacids. The Hammett function can be correlated with colorimetric reagent tests and temperature-programmed desorption results.

[0036] Metal oxide - a term commonly used in academic literature to refer to binary compounds of metal elements and oxygen. Depending on their position in the periodic table, metal oxides range from weakly basic to amphoteric (exhibiting both acidic and basic properties) in their pure molecular state. Weakly basic metal oxides are the oxides of lithium, sodium, magnesium, potassium, calcium, rubidium, strontium, indium, cesium, barium, and tellurium. Amphoteric oxides are the oxides of beryllium, aluminum, gallium, germanium, astatine, tin, antimony, lead, and bismuth.

[0037] Monodisperse--characterized by particles of uniform size that are substantially separate from one another and not agglomerated into grains of larger particles.

[0038] pH - a numerical scale of functions commonly used in scientific literature to specify the acidity or alkalinity of aqueous solutions. It is the function of the hydronium ion [HO +

[0047] As used herein, it describes the relative acidity of nanoparticles suspended in an aqueous solution.

[0039] Surface functionalization - The attachment of small atomic or molecular groups to the surface of a material.

[0040] Superacid - A substance that is more acidic than 100% H2SO4 and has a Hammett function of H0<-12. DETAILED DESCRIPTION OF THE INVENTION

[0041] Referring now to FIG. 1 , a lithium-ion battery cell 100 is shown in a simplified cross-sectional view. The cell 100 may include a casing or container 102. In some embodiments, the casing 102 is a polymer or alloy. The casing 102 chemically and electrically isolates the contents of the cell 100 from adjacent cells, from contamination, and from damage or injury from other components of the device in which the cell 100 is installed. A complete battery may include multiple cells arranged in a series and / or parallel configuration. The battery may have additional casings or fastening mechanisms that join multiple cells together, as known in the art.

[0042] The cell 100 provides a cathode 104 and an anode 106. The contents of the cell 100 undergo a chemical reaction when a conductive path external to the cell 100 is provided between the cathode 104 and the anode 106. As a result of the chemical reaction, electrons are provided at the anode 106, and these electrons flow to the cathode 104 through a circuit (sometimes called a load) external to the battery. At a basic level, during discharge of the cell 100, the materials comprising the anode 106 are oxidized, providing the electrons that flow through the circuit. As a recipient of the electrons released by the anode 106, the materials comprising the cathode 104 are reduced.

[0043] Within cell 100, during discharge, metal cations migrate through electrolyte 108 from anode 106 to cathode 104. In lithium-based batteries, the metal cations are lithium cations (Li + The electrolyte 108 can be a liquid electrolyte, such as a lithium salt in an organic solvent (e.g., LiClO4 in ethylene carbonate). Other electrolytes known in the art can also be used. Lithium-based electrolyte / solvent combinations may also be used. In some cases, the electrolyte 108 may be a solid electrolyte, such as a lithium salt in polyethylene oxide. Optionally, the electrolyte may include a polymer electrolyte. Examples of electrolytes include those described in U.S. Patent Application Publication No. 2017 / 0069931, which is incorporated herein by reference.

[0044] A separator 110 may be used to prevent contact between the electrodes 104, 106. The separator 110 may be a porous layer material that is permeable to lithium ions and the electrolyte 108 but is not otherwise electrically conductive to prevent internal shorting of the cell 100. As is known in the art, the separator 110 may comprise glass fibers or, optionally, a polymer having a semi-crystalline structure. Additional components, such as current collectors, may also be included in the cell 100 but are not shown in FIG. 1 .

[0045] The anode 104, cathode 106, electrolyte 108, and separator 110 together form the complete cell 100. The separator 110 is porous so that the electrolyte 108 can flow into or be contained within the separator 110. Under normal operating conditions, the porosity of the separator 110 allows the ions (Li + ) is allowed to flow between the electrodes 104, 106 via the electrolyte 108. As is known in the art, separators can be constructed such that if exposed to an excess of heat or a runaway exothermic reaction, the internal pore structure will melt and close, shutting down the cell.

[0046] Most lithium-based batteries are so-called secondary batteries. Secondary batteries can be discharged and recharged many times until the chemical or structural integrity of the cell drops below acceptable limits. Cells and batteries according to the present disclosure are considered both primary (e.g., single-use) and secondary batteries.

[0047] In the case of cell 100 being a secondary battery (or part of a secondary battery), it should be understood that cell 100 may be recharged singly or as a component of a complete system in which multiple cells are recharged simultaneously (and possibly in the same parallel or series circuit).

[0048] To charge, a reverse voltage is applied to cell 100. It should be understood that various schemes for effectively recharging a lithium battery can be used. Constant current, variable current, constant voltage, variable voltage, partial duty cycle, etc. may be used. This disclosure is not intended to be limited to any particular charging method unless otherwise stated in the claims. During charging of cell 100, element 115 represents a voltage source applied between cathode 104 and anode 106, providing electrons from cathode 105 to anode 106 and allowing a chemical reaction to occur. Lithium ions migrate from cathode 104 back to anode 106 through electrolyte 108 and separator 110.

[0049] By way of example, the cathode 104 or the anode 106 may independently comprise an AMO material disclosed herein. When an AMO material is used as the cathode, the anode may correspond to a lithium intercalation material, such as lithium metal or graphite. Optionally, the electrolyte 108 may comprise an acidic species dissolved in an organic solvent along with a lithium salt. In addition to, or as an alternative to, the use of an acidic species in the electrolyte 108, the electrode (i.e., the cathode 104 or the anode 106) may optionally comprise AMO and an acidic species. Oxalic acid is an exemplary acidic species.

[0050] Without wishing to be bound by any theory, it is believed that the presence of acidic species in the cathode 104 or anode 106 and / or electrolyte 108 improves the surface affinity of the AMO material for lithium ions, thereby improving its ability to absorb lithium ions during discharge. It is believed that this improves the overall capacity compared to similar cells lacking acidic species or having basified electrodes or electrolytes (i.e., containing basic species). Alternatively, or in addition, the presence of acidic species may allow additional active sites for lithium absorption at the cathode 104.

[0051] It should be understood that Figure 1 is not to scale. As shown in Figure 2, in most applications, the separator 110 occupies most or all of the space between and is in contact with the electrodes 104, 106. In such cases, the electrolyte 108 is contained within the separator 110 (although it may penetrate the pores or surfaces of the anode or cathode). Figure 2 is also not necessarily to scale. The actual geometry of the cell can range from a relatively thin, flat pouch to a canister-type structure, button cell, etc. Cell construction techniques such as wound, bobbin, or pin-type assemblies may be used.

[0052] Current collectors and other components (not shown) known in the art can also be included to form the cell 100 into a commercially usable package. While the overall shape or geometry can vary, a cell or battery typically includes electrodes 104, 106 that are separated rather than touching at some location or cross-section, with an electrolyte 108 and optionally a separator 110 between the electrodes 104, 106. Cells may also be constructed with multiple layers of anodes and cathodes. Cells may also be configured with two cathodes on opposite sides of a single anode, or vice versa.

[0053] A functional or operable battery intended for a particular purpose may comprise multiple cells arranged according to the needs of a particular application. An example of such a battery is shown schematically in FIG. 3. Here, battery 300 includes four lithium cells 100 arranged in series to increase voltage. Capacity can be increased at this voltage by providing an additional stack of four cells 100 in parallel with the stack shown. Different voltages can be achieved by varying the number of cells 100 arranged in series.

[0054] The positive electrode 306 may be accessible outside the casing 302 of the battery 300. A negative electrode 304 is also provided. The physical form factor of the electrodes 304, 306 may vary depending on the application. Various binders, adhesives, tapes, and / or other fastening mechanisms (not shown) may be used within the battery casing 302 to stabilize the other components. Batteries based on lithium technology are generally operable, rechargeable, and storable (in the case of secondary batteries) in any orientation. As noted above, the cell 100 may take on a variety of different geometric shapes. Thus, FIG. 3 is not intended to represent a particular physical form factor of the battery 300.

[0055] The battery 300 may also include various auxiliary circuits 308 disposed within the casing 302 of the battery 300 between the positive electrode 308 and the lithium cell 100. In other embodiments, the auxiliary circuits are disposed between the negative electrode 304 and the lithium battery 100 instead of, or in addition to, being disposed between the positive electrode 306 and the lithium battery 100. The auxiliary circuits 308 may include short circuit protection, overcharge protection, over-temperature shutdown, and other circuits known in the art for protecting the battery 300, the cell 100, and / or any load attached to the battery 300.

[0056] The composition of the materials selected for the cathode 104, anode 106, and electrolyte can be important to the performance of the cell 100 and any battery of which it forms a part. In the context of this disclosure, various examples of AMOs and their methods of manufacture are provided in this regard. These AMOs can form anodes or cathodes in half-cells, cells, and batteries. The AMOs of the present disclosure are otherwise compatible with known lithium cell technology, including existing anode compositions, cathode compositions, electrolyte formulations, and separator compositions.

[0057] In the context of the present disclosure, various examples of AMOs and their methods of manufacture and use are provided. These AMOs are suitable for use in forming cathodes or anodes in half-cells, cells, and batteries. The disclosed AMOs are compatible with conventional lithium battery technology, including otherwise existing anode compositions, cathode compositions, electrolyte formulations, and separator compositions. It will be understood that the anode 106 material selected for a cell or battery according to the present disclosure may be less electronegative than the cathode material and may suitably complement the cathode material. In one particular embodiment, the disclosed AMOs are useful as cathodes in cells having a lithium metal anode.

[0058] In various embodiments of the present disclosure, the cathode 104 comprises an AMO material having an acidic, but not super-acidic, surface. This may be in contrast to materials previously known and utilized as cathodes, such as lithium cobalt or lithium manganese materials. The AMO materials of the present disclosure and their methods of manufacture are described below. In other embodiments, the anode 106 comprises an AMO material of the present disclosure having an acidic, but not super-acidic, surface.

[0059] The surface of a metal oxide is ideally an array of metal and oxygen centers, aligned according to the oxide's crystalline structure. In reality, the array is imperfect and prone to vacancies, distortions, and surface deposits. Regardless, all exposed metal centers are cationic (positively charged) and can accept electrons, thus acting as Lewis acid sites by definition. Oxygen centers are anionic (negatively charged) and act as Lewis base sites, donating electrons. This results in the familiar amphoteric nature of metal oxide surfaces.

[0060] Under normal atmospheric conditions, water vapor present adsorbs onto the surface of metal oxides either in molecular (hydrated) or dissociated (hydroxylated) form. OH - Seed and H + Both species can be adsorbed on the oxide surface. The negatively charged hydroxyl species binds to the cation (Lewis acid, electron-accepting) center of the metal and forms H + binds to the anion (Lewis base, electron donating) center of oxygen. Both adsorptions result in the presence of the same functional group - hydroxyl - on the metal oxide surface.

[0061] These surface hydroxyl groups can either give up or accept a proton and therefore function as either a Brønsted acid or a Brønsted base. The tendency of an individual hydroxyl group to be a proton donor or proton acceptor is influenced by the coordination of the metal cation or oxygen anion to which it is bound. Metal oxide surface defects such as oxygen vacancies, or coordination of surface groups by other chemical species, mean that not all cations and anions are coordinated equally. Acid and basic sites vary in number and strength. When "aggregated" broadly across the surface of an oxide, this can give the surface an overall acidic or basic character.

[0062] The quantity and strength of Lewis acid and Lewis base sites (from exposed metal cations and oxygen anions, respectively) and Brønsted acid and Brønsted base sites (from surface hydroxyl groups) add a wide range of utility and functionality to metal oxides, enhancing their use in both chemical reactions and device applications. These sites contribute significantly to the chemical reactivity of metal oxides. They can serve as anchor points to which other chemical groups, even additional metal oxides, can bind. They can also affect surface charge, hydrophilicity, and biocompatibility.

[0063] One way to modify the surface of metal oxides is to attach small chemical groups, or electron-withdrawing groups ("EWGs"), in a process known as surface functionalization. The EWGs induce polarization of the hydroxide bonds, promoting hydrogen dissociation. For example, a stronger EWG should result in a more polarized bond, which in turn should result in more acidic protons. The acidity of a Lewis point can be increased by inducing polarization that promotes electron donation to that point. When the compound thus created is placed in water, the acidic protons will dissociate, thus lowering the measured pH of the water.

[0064] Although somewhat imprecise when working with solid rather than liquid acid / base systems, traditional pH measurement methods utilizing titration, pH paper, and pH probes can be used to assess the acidity of metal oxides dispersed in aqueous solutions. These measurements can be supplemented with techniques including, but not limited to, colorimetric reagents, infrared spectroscopy, and thermal desorption data to establish the acidified nature of the metal oxide surface. Surface groups can be examined by standard analytical techniques, including, but not limited to, X-ray photoelectron spectroscopy.

[0065] Surface functionalization can be achieved post-synthesis, including, but not limited to, exposing the metal oxide to an acidic solution or vapor containing the desired functional group. It can also be achieved by solid-phase methods, in which the metal oxide is mixed and / or ground with a solid containing the desired functional group. However, all of these methods require one or more additional surface functionalization steps beyond those required to synthesize the metal oxide itself.

[0066] The synthesis and surface functionalization of AMO materials can be achieved by a "single-pot" hydrothermal synthesis method or equivalent, in which the surface of the metal oxide is functionalized as it is synthesized from the appropriate precursor. The precursor salt containing the EWG is solubilized, and the resulting solution is acidified with an acid containing a second EWG. The acidified solution is then basified, heated, and washed. A drying step produces the solid AMO material.

[0067] As an example, a preferred embodiment of tin oxide in the AMO form was synthesized and simultaneously surface functionalized using the following single-pot method.

[0068] 1. First, dissolve seven grams (7 g) of tin(II) chloride dihydrate (SnCl2·2H2O) in a solution of 35 mL of absolute ethanol and 77 mL of distilled water.

[0069] 2. Stir the resulting solution for 30 minutes.

[0070] The solution is acidified by dropwise addition of 3.7 mL of 1.2 M HCl and the resulting solution is stirred for 15 minutes.

[0071] The solution is basified by adding 4.1 M aqueous base dropwise until the pH of the solution is about 8.5.

[0072] 5. The resulting opaque white suspension is then placed in a water bath (approximately 60-90°C) with stirring for at least 2 hours.

[0073] 6. The suspension is then washed with distilled water and then with absolute ethanol.

[0074] 7. The washed suspension was dried in air at 100°C for 1 hour, and then in air at 200°C. Anneal at RT for 4 hours. This method yields chlorine-surface-functionalized tin AMOs, whose pH is approximately 2 when measured by resuspension at room temperature in aqueous solution at 5% by weight. By definition, their Hammett function is H > -12. While open systems such as flasks are described here, closed systems such as autoclaves can also be used.

[0075] Using the single-pot method disclosed above, several AMOs have been synthesized. Table 1 below lists the precursors and acids used. In some cases, dopants are also used:

[0076] [Table 1] In some embodiments, the electron-withdrawing group has a carbon chain length of 5 or less, or 6 or less, and / or an organic mass (AMU) of 200 or less. In some embodiments, the electron-withdrawing group has a carbon chain length of 8 or less, or 10 or less, and / or an organic mass of 500 or less.

[0077] It will be understood that the parameters of this method can be varied, including, but not limited to, the type and concentration of reagents, the type and concentration of acid and base, reaction time, temperature and pressure, agitation speed and time, number and type of washing steps, drying and baking time and temperature, and exposure to gas during drying and baking. They may be performed singly or in any combination, optionally using experimental design techniques. Additionally, other metal oxide synthesis methods, such as spray pyrolysis, vapor deposition, electrodeposition, solid-state methods, and hydrothermal or solvothermal processes, may be useful for achieving the same or similar results as the methods disclosed herein.

[0078] A variety of annealing conditions are useful for preparing AMO nanomaterials. Exemplary annealing temperatures can be below 300°C, e.g., between 100°C and 300°C. Exemplary annealing times can range from about 1 hour to about 8 hours or more. Annealing can be performed under a variety of atmospheric conditions. For example, annealing can be performed in air at atmospheric pressure. Annealing can be performed under elevated pressure (above atmospheric pressure) or reduced pressure (below atmospheric pressure or in a vacuum). Alternatively, annealing can be performed in a controlled atmosphere, such as under an inert gas (e.g., nitrogen, helium, or argon) or in the presence of an oxidizing gas (e.g., oxygen or water).

[0079] A variety of drying conditions are useful for preparing AMO nanomaterials. An example drying temperature can be 50°C to 150°C. Exemplary drying times can range from about 0.5 hours to about 8 hours or more. Drying can be performed under a variety of atmospheric conditions. For example, drying can be performed in air at atmospheric pressure. Drying can be performed under high pressure (above atmospheric pressure) or under reduced pressure (below atmospheric pressure or in a vacuum). Alternatively, drying can be performed in a controlled atmosphere, such as under an inert gas (e.g., nitrogen, helium, or argon) or in the presence of an oxidizing gas (e.g., oxygen or water).

[0080] The performance characteristics of the disclosed AMO nanomaterials differ from those of non-acidified metal oxide nanoparticles. As an example, Figure 4 shows the difference in the cyclic voltammograms of AMO tin prepared by a single-pot method compared to that of commercially available non-AMO tin when cycled against lithium. For example, the surface-functionalized AMO material exhibits better reversibility than the non-AMO material. The presence of distinct peaks in the CV of the AMO material can indicate multiple electron transfer steps occurring during charge / discharge. For example, high-voltage peaks can indicate direct oxidation / reduction of the AMO material, while low-voltage peaks can be attributed to changes in the material structure (i.e., alloying) of the AMO material.

[0081] As another example, Figure 5 shows that the total reflectance of AMO tin oxide differs from that of commercially available non-AMO tin oxide. The data indicates that AMO has a lower bandgap and therefore more desirable properties as a component of photovoltaic systems in addition to its use as an anode according to the present disclosure.

[0082] AMO materials have the general formula M m O x / G (In the formula, M m O x is a metal oxide, m is 1 or more and 5 or less, and x is 1 or more and 21 or less; G is at least one EWG that is not a hydroxide; (The / simply makes a distinction between metal oxides and EWG, and does not imply a fixed numerical relationship or ratio between the two.) It can be thought of as having the following. G may represent a single type of EWG, or it may represent two or more types of EWG.

[0083] An exemplary AMO is acidified tin oxide (Sn x O y ), acidified titanium dioxide (Ti a O b ), acidified iron oxide (Fec O d ), and acidified zirconium oxide (Zr e O f ) Exemplary electron withdrawing groups ("EWG") are Cl, Br, BO3, SO4, PO4, and C According to the present disclosure, regardless of the particular metal or EWG, the AMO material is acidic, but not superacidic, having a pH < 7 when suspended at 5 wt% in aqueous solution and having a Hammett function of H > -12 at least on its surface.

[0084] The AMO materials may be crystalline or amorphous in structure (or a combination thereof) and may be used alone or in combination with each other as composites, with non-acidified metal oxides, or with other additives, binders, or conductive aids known in the art. In other words, anodes fabricated using the AMOs of the present disclosure may or may not contain other materials. In one embodiment, the AMO may be layered on a conductive material to form the cathode 104. In some embodiments, the AMO material may be added to a conductive aid such as graphite or conductive carbon (or their equivalents) in the range of 10% to 80% by weight, and in the range of 90% to greater than 95% by weight. In preferred embodiments, the AMO was added at 10%, 33%, 50%, and 80% by weight.

[0085] To maximize the amount of total available surface area, the AMOs should be in the form of nanoparticulates (i.e., less than 1 micron in size) and substantially monodisperse. More preferably, the nanoparticulates are less than 100 nm in size, and even more preferably less than 20 nm or less than 10 nm in size.

[0086] In mixed metal AMOs, another metal or metal oxide is present in addition to the single or binary oxide, and these mixed metal AMOs have been implemented in forming anodes for use in half-cells, cells, and batteries. These mixed metal AMOs have the general formula Mm N n O x / G and M m N n R r O x / G (In the formula, M is a metal, and m is greater than or equal to 1 and less than or equal to 5; N is a metal, and n is greater than zero and less than or equal to 5; R is a metal, and r is greater than zero and less than or equal to 5; O is the total oxygen associated with all metals, and x is greater than or equal to 1 and less than or equal to 21; / simply makes a distinction between metal oxides and electron-withdrawing surface groups, and does not indicate a fixed numerical relationship or ratio between the two; G is at least one EWG that is not a hydroxide It can be thought of as having the following. G may represent a single type of EWG, or it may represent two or more types of EWG.

[0087] Some prior art mixed metal oxide systems, of which zeolites are the most notable examples, exhibit strong acidity, whereas individual simple oxides do not. A preferred embodiment of the mixed metal AMOs of the present disclosure is that any embodiment is not a simple M m O x The mixed metal oxide systems differ from the prior art in that they must contain at least one AMO that is acidic (not superacidic) in the / G form. Preferred mixed metal and metal oxide systems are Sn x Fe c O y+d and Sn x Ti a O y+b where y+d and y+b may be integer or non-integer values.

[0088] In another embodiment, mixed-metal AMO materials are prepared by a single-pot method with one modification: the synthesis begins with two metal precursor salts in any ratio, rather than one. For example, step 1 of the single-pot method may be modified as follows: first, 3.8 g of tin(II) chloride dihydrate (SnCl 2·2H 0) and 0.2 g of lithium chloride (LiCl) are dissolved in a solution of 20 mL of absolute ethanol and 44 mL of distilled water.

[0089] The metal precursor salts listed in Table 1 can also be used in any proportion. The metal precursor salts can have the same anionic group or different anionic groups, and can be introduced at different times during the synthesis, or can be introduced as a solid or in a solvent, depending on the desired product. In some embodiments, a first metal precursor salt can be used in the primary structure (i.e., a larger proportion) of the resulting AMO, and a second (and optionally a third) metal precursor salt can be added as a dopant or minor component of the resulting AMO.

[0090] Experiments using the single-pot method led to seven notable findings. First, in all cases, both surface functionalization and acidity occur endogenously rather than post-synthetically (see Figure 6). Unlike prior art surface functionalization methods, the single-pot method does not require any additional step or steps for surface functionalization beyond those required to synthesize the metal oxide itself, nor does it utilize hydroxyl-containing organic compounds or hydrogen peroxide.

[0091] Second, this method can be broadly generalized across a wide range of metal oxides and EWGs. Using the disclosed method, we synthesized metal oxides of iron, tin, antimony, bismuth, titanium, zirconium, manganese, and indium, simultaneously surface-functionalizing them with chloride, sulfate, acetate, nitrate, phosphate, citrate, oxalate, borate, and bromide. We also synthesized mixed-metal AMOs: tin and iron, tin and manganese, tin and manganese and iron, tin and titanium, indium and tin, antimony and tin, aluminum and tin, lithium and iron, and lithium and tin. Additionally, surface functionalization can be achieved with EWGs that are weaker than halogens and SO4, which still produce acidic, but not superacidic, surfaces. For example, this method was also used to synthesize AMOs surface-functionalized with acetate (CH3COO), oxalate (CO4), and citrate (C6H5O7). Various embodiments are described below.

[0092] Third, there is a synergistic relationship between EWG and other nanoparticle properties, such as size, morphology (e.g., plate-like, spherical, needle-like, or rod-like), oxidation state, and crystallinity (amorphous, crystalline, or a mixture of these). For example, differences in morphology can occur between AMO nanoparticles synthesized under identical conditions except for the use of different EWGs for surface functionalization (see Figure 7). Surface functionalization can act to "lock" the nanoparticle dimensions, arresting their growth. This locking effect may occur in only one dimension of the nanoparticle, or in two or more dimensions, depending on the exact synthesis conditions.

[0093] Fourth, the properties of AMOs are highly sensitive to the synthesis conditions and procedures. For example, differences in the morphology and performance of AMO nanoparticles can occur when synthesized under identical conditions but with two different total reaction times (see Figures 8 and 9). Experimental design techniques can be used to determine the best or optimal synthesis conditions and procedures, thereby resulting in a desired property or combination of properties.

[0094] Fifth, both the anions present in the precursor salt and the anions present in the acid contribute to the surface functionalization of the AMO. In a preferred embodiment, tin chloride precursors and hydrochloric acid are used to synthesize tin AMOs. The performance of these particles differs from embodiments using tin chloride precursors and sulfuric acid or tin sulfate precursors and hydrochloric acid. Therefore, in some embodiments, it is preferable to match the anions of the precursor and the acid.

[0095] Sixth, when using precursors with weak EWGs and acids with strong EWGs, or vice versa, the strongly attractive anions dominate surface functionalization. This opens up a broader range of synthetic possibilities, allowing functionalization with ions that are not readily available in both the precursor salt and the acid. There is also the possibility of mixed functionalization using both strong and weak EWGs. In one example, tin AMOs are synthesized using tin acetate precursors and phosphoric acid. X-ray photoelectron spectroscopy analysis of the surface shows a higher concentration of phosphorus atoms than the bonds associated with the acetate groups (see Figure 10).

[0096] Seventh, and finally, while the disclosed method is a general procedure for the synthesis of AMOs, the synthesis procedure and conditions may be adjusted to obtain sizes, morphologies, oxidation states, and crystalline states that may be desirable for various applications. As an example, catalytic applications may require AMO materials that are more active in visible light (see FIG. 11A) or more active in ultraviolet light (see FIG. 11B).

[0097] In another example, AMO materials may be used as battery electrodes. Primary (single-use) battery applications may require an AMO with properties that result in the highest capacity, while secondary (rechargeable) battery applications may require the same AMO but with properties that result in the best cycling characteristics. Figure 12 compares the cycling characteristics of two different batteries constructed with AMO materials, including chlorine-containing and sulfur-containing AMO. AMO materials can improve battery performance without degradation of battery components or gassing. This is contrary to what the prior art teaches.

[0098] Figure 13 shows the cycling performance of a battery constructed as a half-cell of AMO nanomaterial electrodes versus lithium metal, demonstrating cycling performance up to 900 cycles while maintaining useful capacity and exceptional coulombic efficiency. Such long cycling performance is particularly remarkable for a lithium metal reference electrode, because lithium metal is known to grow dendrites even after a small number of cycles, leading to dendrite expansion and potentially dangerous and catastrophic battery cell failure.

[0099] According to the present disclosure, in a complete cell, an anode 106 comprising the disclosed AMO can be utilized with a known electrolyte 108 and a cathode 104 comprising known materials such as lithium cobalt oxide (LiCoO). Similarly, materials comprising the separator 110 can be drawn from those currently known in the art.

[0100] In a complete cell, a cathode 104 comprising the disclosed AMO can be utilized with a known electrolyte 108 and an anode 106 comprising known materials, such as carbon on copper foil, that exhibit lower electronegativity than that of the disclosed AMO. Similarly, the materials comprising the separator 110 and electrolyte 108 can be drawn from those currently known in the art, as discussed above.

[0101] Various layering and other strengthening techniques may be deployed to maximize the ability to retain lithium ions for powering the cell 100. It should also be understood that batteries based on the AMO cathode 104 according to the present disclosure can be deployed as secondary (e.g., rechargeable) batteries, but can also function as primary batteries. While the AMO anodes of the present disclosure are suitable for reversible battery chemistries, cells or batteries constructed as described herein may also be fully deployed as primary cells or batteries. Cells and batteries constructed according to the present disclosure, in some embodiments, do not require initial formation and can therefore be immediately used as primary cells or batteries. In other cases, limited formation or rapid formation may be used. Furthermore, deploying the cells and batteries of the present disclosure as primary batteries that are not intended to be recharged provides significant savings. This mitigates some of the safety issues that are thought to be inherent in lithium battery chemistry, although safety issues are known in the art to arise more frequently during battery cycling.

[0102] In other embodiments according to the present disclosure, the cathode 104 comprises tin oxide (SnO), but is not acidified according to the AMO described above. Known electrolytes 108, anodes 106, and separators 110, or those otherwise described in this disclosure, can be utilized in such embodiments.

[0103] It will be understood that other battery configurations are possible using AMO materials. For example, a battery may include a first electrode comprising an AMO nanomaterial, a second electrode, and an electrolyte disposed between the first and second electrodes. As an example in a lithium-ion battery, the first electrode may operate as either a cathode or an anode. For example, in operation as a cathode, the second electrode may correspond to lithium metal, graphite, or another anode material. As another example, in operation as an anode, the second electrode may correspond to LiCoO2, LiMn2O4, LiNiO2, or another cathode material. Useful materials for the second electrode include, but are not limited to, graphite, lithium metal, sodium metal, lithium cobalt oxide, lithium titanate, lithium manganese oxide, lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate, lithium nickel cobalt aluminum oxide (NCA), or any combination thereof.

[0104] The AMO materials of the present disclosure may optionally be used with an acidic component, such as a binder, acidic electrolyte, or acidic electrolyte additive. The AMO materials of the present disclosure may be associated with an anode, cathode, half cell, complete cell, integrated battery, or other component. The inventors surprisingly discovered that including an acidic component and / or acidic species, such as an organic acid or organic acid anhydride, in a battery containing the AMO material increases capacity compared to a battery without the acidic species. Again, the prior art teaches against the use of acidic species, as these species can degrade metal current collectors and housings and cause degradation of other electrode components.

[0105] Figure 14 provides comparative data on the cycling performance of AMO-based batteries formed with the same materials and structure, except for those with standard, basified, and acidified electrolytes. The batteries contained the following structures: all cathodes contained the same AMO material; all anodes were lithium metal; the standard electrolyte was a 1:1:1 mixture of dimethyl carbonate, diethylene carbonate, and ethylene carbonate containing 1 M LiPF; the acidified electrolyte was a standard electrolyte containing 3 wt. % succinic anhydride; and the basified electrolyte was a standard electrolyte containing 3 wt. % dimethylacetamide. All batteries were cycled at the same discharge rate. As shown, the battery with the acidified electrolyte system exhibited the best cycling capability and maintained the highest capacity beyond the maximum number of cycles.

[0106] Figure 15 provides additional comparative cycling data for two different batteries with the same cell configuration, except that one battery contained an acidified electrolyte and the AMO material in one battery was deoxidized by washing with a solvent. The batteries contained the following configuration: the cathode contained the AMO material; the electrolyte was a 1:1:1 mixture of dimethyl carbonate, diethylene carbonate, and ethylene carbonate containing 1 M LiPF and 3 wt. % succinic anhydride; and the anode was lithium metal. The batteries were cycled at the same discharge rate. The battery with the acidified AMO material showed higher capacity retention over cycles, indicating that the acidified surface of the AMO interacts with the acidified electrolyte, improving performance.

[0107] Several acidic electrolytes have been developed and / or tested and found to work advantageously in the cell chemistries described herein. [Example]

[0108] Example 1 Acetate / chloride functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a soft, gray material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 16 shows a plot of the measured capacity versus cycle number, as well as a plot of the voltage as a function of time during cycling.

[0109] Example 2 Acetate / sulfate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of sulfuric acid (HSO). The resulting AMO nanomaterial was a gray, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 17 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0110] Example 3 Acetate / nitrate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of nitric acid (HNO). The resulting AMO nanomaterial was a gray, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 18 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0111] Example 4 Acetate / phosphate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of phosphoric acid (HPO). The resulting AMO nanomaterial was a brown, soft, flaky material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 19 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0112] Example 5 Acetate / citrate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CH3COO)2) was dissolved in an ethanol / water solution and acidified by the addition of citric acid (C6H8O7). The resulting AMO nanomaterial was a brown, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and tested at zero volts. The cells were cycled by discharging to 100 volts and then charging to 1.5 volts. Figure 20 shows a plot of the measured capacity versus cycle number, and a plot of the voltage as a function of time during cycling.

[0113] Example 6 Acetate / citrate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of oxalic acid (CHO). The resulting AMO nanomaterial was a taupe-colored, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 21 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling.

[0114] Example 7 AMOs of tin oxide doped with iron oxide and functionalized with acetate / chloride Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution containing a small amount of iron acetate. This solution was acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a soft, flaky, creamy-gray material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 22 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0115] Example 8 Iron oxide-doped and acetate / sulfate-functionalized tin oxide AMOs Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution containing a small amount of iron acetate. This solution was acidified by the addition of sulfuric acid (HSO). The resulting AMO nanomaterial was a soft, flaky material with a pale taupe color, which was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 23 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling.

[0116] Example 9 Iron oxide-doped, acetate / nitrate-functionalized tin oxide AMOs Two doped tin oxide AMO samples were synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CH3COO)2) was dissolved in an ethanol / water solution containing a small amount of iron acetate (Fe(CH3COO)3). This solution was acidified by the addition of nitric acid (HNO3). The resulting AMO nanomaterial was a soft, white material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 24 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0117] Example 10 Iron oxide-doped and acetate / oxalate-functionalized tin oxide AMOs Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CH3COO)2) was mixed with a small amount of iron acetate (Fe(CH3COO) The AMO nanomaterial was dissolved in an ethanol / water solution containing 3). This solution was acidified by the addition of oxalic acid (C2H2O4). The resulting AMO nanomaterial was a soft, white material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 25 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0118] Example 11 Iron oxide-doped and acetate / phosphate-functionalized tin oxide AMOs Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CH3COO)2) was dissolved in an ethanol / water solution containing a small amount of iron acetate (Fe(CH3COO)3). This solution was acidified by the addition of phosphoric acid (H3PO4). The resulting AMO nanomaterial was a white, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 26 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling.

[0119] Example 12 Iron oxide-doped, acetate / citrate-functionalized tin oxide AMOs Doped tin oxide was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CH3COO)2) was dissolved in an ethanol / water solution containing a small amount of iron acetate (Fe(CH3COO)3). This solution was acidified by adding citric acid (C6H8O7). The resulting material was a yellow, glassy, ​​hard material without particle formation, which formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 27 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0120] Example 13 Acetate / bromide functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of hydrobromic acid (HBr). The resulting AMO nanomaterial was a gray, soft, powdery material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 2628 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0121] Example 14 Acetate / borate functionalized tin oxide AMOs Tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin acetate (Sn(CHCOO)) was dissolved in an ethanol / water solution and acidified by the addition of boric acid (HBO). The resulting AMO nanomaterial was a gray, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 29 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0122] Example 15 Manganese oxide doped and sulfate / chloride functionalized tin oxide AMO Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin sulfate (SnSO4) was dissolved in an ethanol / water solution containing a small amount of manganese chloride (MnCl2). This solution was acidified by the addition of sulfuric acid (H2SO4). The resulting AMO nanomaterial was a very soft, tan-colored material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 30 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0123] Example 16 AMO of manganese oxide doped and chloride functionalized tin oxide Doped tin oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, tin chloride (SnCl) was dissolved in an ethanol / water solution containing a small amount of manganese chloride (MnCl). This solution was acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a soft, gray-brown material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 31 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0124] Example 17 AMOs of tin oxide doped with iron oxide and aluminum oxide and functionalized with chloride Two doped tin oxide AMO samples were synthesized using a single-pot hydrothermal synthesis method. Briefly, tin chloride (SnCl2) was dissolved in an ethanol / water solution containing small amounts of both iron chloride (FeCl3) and aluminum chloride (AlCl3). This solution was acidified by adding hydrochloric acid (HCl). The resulting AMO nanomaterial for the first sample was a light tan, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 32 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling. The resulting AMO nanomaterial for the second sample was a light gray, flake-like material.

[0125] Example 18 AMO of iron oxide doped with tin oxide and functionalized with chloride Doped iron oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, iron chloride (FeCl3) was dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl2). The iron to tin ratio was 95:5. The solution was acidified by adding hydrochloric acid (HCl). The resulting AMO nanomaterial was a soft, red material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 33 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling.

[0126] Example 19 AMO of iron oxide doped with tin oxide and functionalized with chloride Doped iron oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, iron chloride (FeCl3) was dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl2). The iron to tin ratio was 95:5. The solution was acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a black glassy material that could be formed into an electrode. The electrodes were assembled into battery cells against lithium metal and cycled by discharging to zero volts and then charging to 1.5 volts. Figure 34 shows a plot of the measured capacity versus cycle number, as well as a plot of the voltage as a function of time during cycling.

[0127] Example 20 Nitrate-functionalized iron oxide AMOs Iron oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, iron nitrate Fe(NO3)3 was dissolved in an ethanol / water solution and acidified by the addition of nitric acid (HNO3). The resulting AMO nanomaterial was a black, glassy material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 35 shows a plot of the measured capacity versus cycle number, as well as a plot of the voltage as a function of time during cycling.

[0128] Example 21 Chloride-functionalized bismuth oxide AMO Bismuth oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, bismuth chloride (BiCl) was dissolved in an ethanol / water solution and acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a soft, white material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 36 shows a plot of the measured capacity versus cycle number, as well as a plot of the voltage as a function of time during cycling.

[0129] Example 22 AMO of sulfate-functionalized zirconium oxide Zirconium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, zirconium sulfate (Zr(SO)) was dissolved in an ethanol / water solution and acidified by the addition of sulfuric acid (HSO). The resulting AMO nanomaterial was a flaky, white material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 37 shows a plot of the measured capacity versus cycle number, as well as a plot of the voltage as a function of time during cycling.

[0130] Example 23 AMO of sulfate-functionalized titanium dioxide Titanium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, titanyl sulfate (TiOSO4) was dissolved in an ethanol / water solution and acidified by the addition of sulfuric acid (H2SO4). The resulting AMO nanomaterial was a white, flake-like material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 38 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0131] Example 24 Sulfate-functionalized antimony oxide AMOs Antimony oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, antimony sulfate (Sb2(SO4)3) was dissolved in an ethanol / water solution and acidified by the addition of sulfuric acid (H2SO4). The resulting AMO nanomaterial was a very soft, white material that was formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 3 9 shows a plot of the measured capacity versus cycle number, and a plot of the voltage as a function of time during cycling.

[0132] Example 25 Chloride-functionalized indium oxide AMOs Indium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, indium chloride (InCl) was dissolved in an ethanol / water solution and acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a white material and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 40 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0133] Example 26 Sulfate-functionalized indium oxide AMOs Indium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, indium sulfate (In2(SO4)3) was dissolved in an ethanol / water solution and acidified by the addition of sulfuric acid (H2SO4). The resulting AMO nanomaterial was a white material and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 41 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0134] Example 27 Bromide-functionalized indium oxide AMOs Indium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, indium bromide (InBr) was dissolved in an ethanol / water solution and acidified by the addition of hydrobromic acid (HBr). The resulting AMO nanomaterial was a bluish-white material and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 42 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0135] Example 28 Chloride-functionalized indium oxide AMOs Indium oxide AMO was synthesized using a single-pot hydrothermal synthesis method. Briefly, indium chloride (InCl) was dissolved in an ethanol / water solution and acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was gray with a yellow ring and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 43 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0136] Example 29 Mixed lithium and iron oxide AMOs doped with tin oxide and functionalized with chloride / acetate Doped mixed lithium and iron oxide AMOs were synthesized using a single-pot hydrothermal synthesis method. Briefly, lithium acetate (Li(CH3COO)) and iron chloride (FeCl3) were dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl2). The solution was acidified by the addition of hydrochloric acid (HCl). During the synthesis, a green ring appeared in the flask. A slightly yellow-brownish pinkish color developed. However, the final AMO nanomaterial formed on the electrode was gray. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and then charging to 1.5 volts. Figure 44 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0137] Example 30 Mixed lithium and iron oxide AMOs doped with tin oxide and functionalized with chloride / acetate Doped mixed lithium and iron oxide AMOs were synthesized using a single-pot hydrothermal synthesis method. Briefly, lithium acetate (Li(CHCOO)) and iron chloride (FeCl) were dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl). This solution was acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a pale gold-colored material and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 45 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0138] Example 31 Mixed lithium and iron oxide AMOs doped with tin oxide and functionalized with chloride / acetate Doped mixed lithium and iron oxide AMOs were synthesized using a single-pot hydrothermal synthesis method. Briefly, lithium acetate (Li(CHCOO)) and iron chloride (FeCl) were dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl). This solution was acidified by the addition of hydrochloric acid (HCl). The resulting AMO nanomaterial was a thin, milky-white material and formed into an electrode. The electrode was incorporated into a battery cell against lithium metal and cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 46 shows an electron microscope image of the AMO nanomaterial, a plot of the measured capacity versus cycle number, and a plot of voltage as a function of time during cycling.

[0139] In various examples, the present disclosure provides materials comprising solid metal oxides in the form of monodisperse nanoparticles. The AMO nanomaterials may include tin oxide, titanium dioxide, iron oxide, zirconium oxide, or any combination thereof. The AMO nanomaterials may be surface functionalized with one or more electron-withdrawing groups selected from the group consisting of Cl, Br, BO3, SO4, PO4, NO3, CH3COO, CO4, and C6H5O7. The first battery electrode may further include a second acidic species. The second electrode may include graphite, lithium metal, sodium metal, lithium cobalt oxide, lithium titanate, lithium manganese oxide, lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate, lithium nickel cobalt aluminum oxide (NCA), or any combination thereof. The acidic species may include one or more organic acids selected from the group consisting of oxalic acid, acetic acid, citric acid, maleic acid, methylmalonic acid, glutaric acid, succinic acid, methylsuccinic acid, methylenesuccinic acid, and citraconic acid. The acidic species may include one or more organic acid anhydrides selected from the group consisting of glutaric anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, and itaconic anhydride. The acidic species may have a concentration in the solvent selected from the range of 0.01% to 10% by weight. The acidic species may exhibit a pKa of 1 to 6 in water. The electrolyte may further include a lithium salt dissolved in the solvent.

[0140] The present disclosure provides a method for fabricating an acidified metal oxide (AMO) nanomaterial, forming a first electrode of the AMO nanomaterial, forming an electrolyte by dissolving one or more salts and an acidic species in a solvent, and disposing the electrolyte between the first electrode and a second electrode. The method for fabricating an AMO nanomaterial may include forming a solution containing a metal salt, ethanol, and water, acidifying the solution by adding an acid to the solution, basifying the solution by adding an aqueous alkaline solution to the solution, collecting a precipitate from the solution, washing the precipitate, and drying the precipitate. The method may also include forming a first electrode by mixing the precipitate with a second acidic species. The AMO nanomaterial may include tin oxide, titanium dioxide, iron oxide, zirconium oxide, or any combination thereof. The AMO nanomaterial may be surface functionalized with one or more electron-withdrawing groups selected from the group consisting of Cl, Br, BO3, SO4, PO4, NO3, CH3COO, CO4, and C6H5O7. The second electrode may comprise graphite, lithium metal, sodium metal, lithium cobalt oxide, lithium titanate, lithium manganese oxide, lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate, lithium nickel cobalt aluminum oxide (NCA), or any combination thereof. The acidic species may comprise one or more organic acids selected from the group consisting of oxalic acid, acetic acid, citric acid, maleic acid, methylmalonic acid, glutaric acid, succinic acid, methylsuccinic acid, methylenesuccinic acid, and citraconic acid, or the acidic species may comprise one or more organic acid anhydrides selected from the group consisting of glutaric anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, and itaconic anhydride. The acidic species may have a concentration in the solvent selected from the range of 0.01% to 10% by weight. The acidic species may exhibit a pKa of 1 to 6 in water.

[0141] The present disclosure provides an acidified electrolyte for use in a battery including a first electrode and a second electrode, the first electrode comprising an acidified metal oxide (AMO) nanomaterial, the electrolyte comprising a solvent, one or more metal salts dissolved in the solvent, and an acidic species dissolved in the solvent, the acidic species being different from the one or more metal salts. The acidic species may comprise one or more organic acids selected from the group consisting of oxalic acid, acetic acid, citric acid, maleic acid, methylmalonic acid, glutaric acid, succinic acid, methylsuccinic acid, methylenesuccinic acid, and citraconic acid, or the acidic species may comprise one or more organic acid anhydrides selected from the group consisting of glutaric anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, and itaconic anhydride. The acidic species may exhibit a pKa of 1 to 6 in water.

[0142] All references throughout this application, such as patent documents, including issued or granted patents or equivalents, patent application publications, and non-patent literature documents, or other materials, are incorporated by reference in their entirety herein, as though individually incorporated by reference.

[0143] All patents and publications mentioned herein are indicative of the level of skill of those skilled in the art to which this invention pertains. The references cited herein are hereby incorporated by reference in their entirety to indicate the state of the art at the time of filing, if necessary, and it is intended that this information may be used herein to exclude (e.g., disclaim) certain embodiments that are in the prior art. For example, if a compound is claimed, it should be understood that compounds known in the prior art, including specific compounds disclosed in the references disclosed herein (e.g., particularly referenced patent documents), are not intended to be included in the claim.

[0144] When a group of substituents is disclosed herein, it is understood that all individual members of that group, as well as all subgroups and classes that can be formed using the substituents, are separately disclosed. When Markush groups or other groupings are used herein, all individual members of the group, and all possible combinations and subcombinations of the group, are individually included in the disclosure. As used herein, "and / or" means that one, all, or any combination of the items in the list separated by "and / or" is included in the list; for example, "1, 2, and / or 3" is "1" or "2" or "3", or "1 and 2" or "1 and 3" or "2 and 3", or equivalently "1, 2 and 3".

[0145] Unless otherwise specified, the present invention can be practiced using any combination or formulation of components described or exemplified. Specific names of materials are intended as examples, and it is recognized that one skilled in the art can give the same material different names. Those skilled in the art will understand that methods, device elements, starting materials, and synthetic methods other than those specifically exemplified can be used in the practice of the present invention without resorting to undue experimentation. All art-known functional equivalents of such methods, device elements, starting materials, and synthetic methods are intended to be included in the present invention. Where ranges are given herein, for example, temperature ranges, time ranges, or composition ranges, all intermediate ranges and subranges, and all individual values ​​contained in the given ranges are intended to be included in the present disclosure.

[0146] As used herein, "comprising" is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended, and does not exclude additional, unrecited elements or method steps. As used herein, "consisting of" excludes any element, step, or ingredient not specified in the claim element. As used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Recitation herein of the term "comprising," particularly in describing components of a composition or elements of a device, is understood to encompass compositions and methods consisting essentially of and consisting of the recited components or elements. The invention illustratively described herein can suitably be practiced in the absence of any element or limitation not specifically disclosed herein.

[0147] The terms and expressions which have been employed are used as terms of description and not of limitation, and no intention is intended in the use of such terms and expressions to exclude equivalents of the features shown and described or portions thereof, recognizing that various modifications are possible within the scope of the invention as set forth in the claims. Thus, while the present invention has been specifically disclosed by preferred embodiments and optional features, it should be understood that modifications and variations of the concepts disclosed herein may be possible by those skilled in the art, and that such modifications and variations are considered to be within the scope of the invention as defined by the claims. [Mode of Invention] [1] 1. A battery cell comprising an anode, an electrolyte, and a cathode, wherein one of the anode or the cathode comprises at least one solid metal oxide nanomaterial comprising a surface that is acidic but not superacidic, the surface having, after drying, a pH less than 5 when resuspended at 5 wt % in water, and a Hammett function H0 greater than -12. [2] 2. The battery cell of claim 1, wherein the solid metal oxide nanomaterial has at least one particle dimension less than 100 nm in size. [3] 2. The battery cell of claim 1, wherein the solid metal oxide nanomaterial has at least one particle dimension of less than 20 nm in size. [4] 2. The battery cell of claim 1, wherein the solid metal oxide nanomaterial has at least one particle dimension less than 10 nm in size. [5] 2. The battery cell of claim 1, wherein the solid metal oxide nanomaterial comprises a substantially monodisperse nanoparticle morphology. [6] 2. The battery cell of claim 1, wherein the surface, after drying, has a pH of less than 4 when resuspended at 5% by weight in water, and a Hammett function H of less than −12. [7] 2. The battery cell of claim 1, wherein the surface, after drying, has a pH of less than 3 when resuspended at 5% by weight in water and a Hammett function H0 of greater than -12. [8] 1. A battery cell having an electrode comprising at least one solid metal oxide material, wherein the metal oxide is substantially monodisperse and surface functionalized with a material providing acidic electron-withdrawing groups having a molecular weight of less than 200. [9] 9. The battery cell of claim 8, wherein the material surface functionalizing the surface of the metal oxide is acidic but not superacidic, having a pH of less than 7 when suspended at 5 wt % in an aqueous solution, and a Hammett function H of greater than −12.

[10] 10. The battery cell of claim 9, wherein the material surface functionalizing the surface of the metal oxide is acidic but not superacidic, having a pH of less than 5 when suspended at 5 wt % in an aqueous solution, and a Hammett function H of greater than −12 on at least its surface.

[11] 10. The battery cell of claim 9, wherein the acidic metal oxide comprises tin.

[12] 12. The battery cell according to claim 11, wherein the acidic metal oxide containing tin is surface functionalized with chloride.

[13] 12. The battery cell of claim 11, wherein the acidic metal oxide containing tin is surface functionalized with sulfate.

[14] 10. The battery cell of claim 9, wherein the acidic metal oxide comprises iron.

[15] 15. The battery cell of claim 14, wherein the acidic metal oxide containing iron is surface functionalized with chloride.

[16] 15. The battery cell of claim 14, wherein the acidic metal oxide containing iron is surface functionalized with sulfate.

[17] M m O x A battery cell having a cathode comprising a solid metal oxide nanomaterial of M morphology, m is a metal, and O x is the total oxygen, and M m O x is a metal oxide, G is at least one electron-withdrawing surface group, and " / " distinguishes between the metal oxide and the electron-withdrawing surface group, and the battery electrode solid metal oxide nanomaterial, after drying, has a pH of less than 5 when resuspended at 5 wt % in water and a Hammett function H of greater than -12 on at least its surface.

[18] The solid metal oxide nanomaterial constituting the cathode is a second, different metal "N" where n is greater than zero and not greater than 5. n 18. The battery cell according to claim 17, including:

[19] The solid metal oxide nanomaterial constituting the cathode is a third different metal "R r 19. The battery cell according to claim 18, including:

[20] 18. The battery cell of 17, further comprising an anode of a non-acidic material. [twenty one] M m O xA battery cell having an anode comprising a solid metal oxide nanomaterial of M form, m is a metal, and O x is the total oxygen, and M m O x is a metal oxide, G is at least one electron-withdrawing surface group, and " / " distinguishes between the metal oxide and the electron-withdrawing surface group, and the battery electrode solid metal oxide nanomaterial, after drying, has a pH of less than 5 when resuspended at 5 wt % in water and a Hammett function H of greater than -12 on at least its surface. [twenty two] The solid metal oxide nanomaterial constituting the cathode is a second, different metal "N" where n is greater than zero and not greater than 5. n 22. The battery cell according to claim 21, including: [twenty three] The solid metal oxide nanomaterial constituting the cathode is a third different metal "R r 22. The battery cell according to claim 21, including: [twenty four] 22. The battery cell of claim 21, further comprising a cathode of a non-acidic material.

Claims

1. 1. A battery cell comprising an acidified metal oxide nanomaterial in solid form, The acidified metal oxide nanomaterial comprises an acidified metal oxide in nanoparticle form exhibiting a pH of less than 7 and a Hammett function greater than −12, wherein the pH is measured when the acidified metal oxide in solid form is suspended in water at 5 wt %, and the acidified metal oxide comprises an oxide of at least one first metal selected from the group consisting of titanium, manganese, iron, zirconium, indium, tin, antimony, and bismuth, and the acidified metal oxide does not contain Cl, Br, BO. ３ , S.O. ４ , P.O. ４ , NO ３ , C.H. ３ COO, C ２ O ４ and C ６ H ５ O ７ is surface-functionalized with an electron-withdrawing group selected from Battery cell.

2. 2. The battery cell of claim 1, wherein the acidified metal oxide comprises tin oxide, manganese oxide, or a combination of tin oxide and manganese oxide, and the acidified metal oxide is doped with at least one of iron oxide, titanium oxide, or zirconium oxide.

3. 3. The battery cell of claim 2, wherein the iron oxide, titanium oxide, or zirconium oxide is an acidified form of iron oxide, titanium oxide, or zirconium oxide, respectively.

4. 10. The battery cell of claim 1, wherein the nanoparticle morphology comprises particles having a size less than 100 nm.

5. 10. The battery cell of claim 1, wherein the acidified metal oxide nanomaterial exhibits amorphous or mixed amorphous and crystalline properties.

6. The battery cell of claim 1 , wherein the nanoparticles exhibit a plate-like, spherical, needle-like, or rod-like morphology.

7. 10. The battery cell of claim 1, wherein the acidified metal oxide is in the form of monodispersed nanoparticles.

8. A battery cell including two electrodes and an electrolyte, a first electrode of the two electrodes comprising an acidified metal oxide nanomaterial, the acidified metal oxide nanomaterial comprising an acidified metal oxide in nanoparticle form exhibiting a pH of less than 7 and a Hammett function greater than −12, wherein the pH is measured when the acidified metal oxide in solid form is suspended in water at 5 wt %, and the acidified metal oxide comprises at least one first metal selected from the group consisting of titanium, manganese, iron, zirconium, indium, tin, antimony, and bismuth, and the acidified metal oxide is at least one first metal selected from the group consisting of Cl, Br, BO ３ , S.O. ４ , P.O. ４ , NO ３ , C.H. ３ COO, C ２ O ４ and C ６ H ５ O ７ and The second electrode of the two electrodes constitutes a counter electrode. Battery cell.

9. 9. The battery cell of claim 8, wherein the first electrode is a cathode.

10. 9. The battery cell of claim 8, wherein the second electrode is an anode comprising graphite or lithium metal.

11. 10. The battery cell of claim 8, wherein the acidified metal oxide nanomaterial has at least one particle dimension less than 100 nm in size.

12. 10. The battery cell of claim 8, wherein the acidified metal oxide nanomaterial is in monodisperse nanoparticle form.

13. 9. The battery cell of claim 8, wherein the acidified metal oxide comprises tin oxide, manganese oxide, or a combination of tin oxide and manganese oxide, and the acidified metal oxide is doped with at least one of iron oxide, titanium oxide, or zirconium oxide.

14. 14. The battery cell of claim 13, wherein the iron oxide, titanium oxide, or zirconium oxide is an acidified form of iron oxide, titanium oxide, or zirconium oxide, respectively.

15. 10. The battery cell of claim 8, wherein the electrolyte comprises an acidic electrolyte comprising a solvent, a lithium salt, and an acidic species dissolved in the solvent, wherein the acidic species exhibits a pKa of 1 to 6 in water.

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