Battery cell with a new structure

Abstract

To provide a battery cell comprising an AMO material capable of improving a device in the capacity, cycle characteristics and life.SOLUTION: A battery cell comprises an acidified metal oxide ("AMO") material, preferably in monodispersed nanoparticulate form 20 nm or less in size, having a pH less than 7 when suspended in a 5-wt.% aqueous solution and a Hammett function H0 greater than -12, at least on 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 / 507,658, filed May 17, 2017, entitled "Battery Cell Having a Novel Structure," and incorporates such provisional application by reference into this disclosure as if fully set forth herein at this time.

[0002] 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. In some embodiments, the battery cells are constructed with AMO cathodes and anodes consisting essentially of elemental lithium. [Background technology]

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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. , existing battery construction techniques should be updated to take full advantage of new and known materials available in accordance with this disclosure. Summary of the Invention [Means for solving the problem]

[0009] 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 may optionally be used in combination with acidic species to enhance their utility.

[0010] This application further describes high-capacity electrochemical cells comprising electrodes containing metal oxides. Techniques for preparing metal oxides and electrochemical cells comprising metal oxides are further disclosed. Optionally, the disclosed metal oxides may be used in combination with conductive materials to form electrodes. The formed electrodes are useful with metallic lithium as a corresponding counter electrode and conventional lithium-ion electrodes. Optionally, the disclosed metal oxides may be used in combination with acidic species to enhance their usefulness.

[0011] In some embodiments, the present disclosure provides layered electrode structures with low active material (i.e., metal oxide) loadings. In some cases, less than 80 wt. % active material is used in the electrode. This contrasts with conventional electrochemical cell technologies that attempt to maximize active material loadings, which can be about 80 wt. % or greater, e.g., 90 wt. %, 95 wt. %, or 99 wt. While high active material loadings can be useful for increasing capacity in conventional electrochemical cell technologies, the inventors have discovered that lower active material loadings actually enable higher cell capacities using various embodiments of the present disclosure. Such increased capacity can be achieved, at least in part, by additional physical volume that may be available at lower active material loading levels, allowing for the absorption of more shuttle ions (i.e., lithium ions). Alternatively or additionally, such increased capacity can be achieved, at least in part, by allowing more active sites to absorb shuttle ions, resulting in less blocking of active sites by additional material mass.

[0012] 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.

[0013] 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 the appropriate precursors. In some embodiments, this single-pot method does not require any additional step or steps for acidification beyond those required to synthesize the metal oxide itself, resulting in an AMO material with the desired surface acidity (but not superacidic).

[0014] Optionally, surface functionalization may be performed using strong electron-withdrawing groups ("EWGs") such as SO4, PO4, halogens (Br, Cl, etc.), alone or in combination with each other. Surface functionalization may also be performed with EWGs that are weaker than SO4, PO4, or halogens. For example, synthetic metal oxides may contain acetate groups (CH3COO), oxalate groups (CO4 ), and citrate (C6H5O7) groups.

[0015] 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.

[0016] 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.

[0017] An exemplary battery cell includes a first electrode, e.g., a first electrode including a metal oxide (which may optionally be an AMO nanomaterial), a conductive material, and a binder; a second electrode, e.g., a second electrode including metallic lithium; and an electrolyte disposed between the first and second electrodes. Optionally, the metal oxide may comprise less than 80 weight percent of the first electrode. Exemplary electrolytes include electrolytes including a metal salt dissolved in a solvent, solid electrolytes, and gel electrolytes. Optionally, a separator may be disposed between the first and second electrodes.

[0018] 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 provide 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 may also be improved with the use of acidic electrodes or electrodes containing acidic species, such as when the battery's cycle life is extended by up to 100 cycles or more. As an example, acidic electrodes or electrodes 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 wt %.

[0019] An electrode according to the present disclosure can include a layered structure including a first set of layers including a conductive material and a second set of layers including a metal oxide, such as an acidified metal oxide (AMO) nanomaterial. Optionally, the first set of layers and the second set of layers can be provided in an alternating configuration. Optionally, the first set of layers and the second set of layers can independently include 1 to 20 layers. Optionally, the first set of layers and the second set of layers independently have a thickness between 1 μm and 50 μm, between 2 μm and 25 μm, between 3 μm and 20 μm, between 4 μm and 15 μm, or between 5 μm and 10 μm. Optionally, the metal oxide may comprise between 5 and 90 weight percent of the second layer set, e.g., 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 weight percent of the second layer set. Optionally, the conductive material and binder may each independently comprise between 5 and 90 weight percent of the first layer set, e.g., 25, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 weight percent of the first layer set.

[0020] The first electrode may optionally include a metal oxide in an amount of up to 95 weight percent of the first electrode, up to 80 weight percent of the first electrode, up to 70 weight percent of the first electrode, between 1 and 50 weight percent of the first electrode, between 1 and 33 weight percent of the first electrode, between 15 and 25 weight percent of the first electrode, between 55 and 70 weight percent of the first electrode, between 20 and 35 weight percent of the first electrode, or between 5 and 15 weight percent of the first electrode. Specific examples of metal oxide weight percent in the first electrode include 1%, 5%, 11%, 12%, 13%, 14%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 60%, 61%, 62%, 63%, 64%, 65%, etc. Without limitation, the electrode loading (percent metal oxide) may range from 1 to 95%, 10 to 80%, 20 to 70%, 30 to 40%, 40 to 50%, 50 to 60%, 60 to 70%, or 80 to 100%. In various embodiments, the loading value may vary by ±1%, 2%, 5%, or 10%. Optionally, the conductive material and binder may each independently comprise the majority of the remainder of the first electrode. For example, the conductive material and binder each independently comprise between 10 and 74 weight percent of the first electrode. Optionally, the conductive material and binder together comprise between 20 and 90 weight percent of the first electrode. Optionally, the AMO nanomaterial may be added as a dopant at 1 to 10 weight percent to conventional lithium-ion electrodes, such as graphite or lithium cobalt oxide.

[0021] Various materials are useful for the electrodes described herein. Examples of metal oxides include, but are not limited to, lithium-containing oxides, aluminum oxide, titanium oxide, manganese oxide, iron oxide, zirconium oxide, indium oxide, tin oxide, antimony oxide, bismuth oxide, or any combination thereof. Optionally, the oxide may be in the form of AMO. As described herein, the metal oxide optionally contains and / or is surface-functionalized with one or more electron-withdrawing groups selected from Cl, Br, BO3, SO4, PO4, NO3, CH3COO, CO4, C2H2O4, C6H8O7, or C6H5O7. Examples of conductive materials include one or more of graphite, conductive carbon, carbon black, Ketjen black, or conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS), PEDOT:PSS composites, polyaniline (PANI), or polypyrrole (PPY).

[0022] In some embodiments, an electrode comprising an AMO nanomaterial is used in combination with other electrodes to form a cell. For example, the second electrode of such a cell may comprise graphite, metallic lithium, 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), the AMO nanomaterial, or any combination thereof. In one particular embodiment, the first electrode comprises SnO2 AMO and the second electrode comprises metallic lithium.

[0023] Various materials are useful in the electrodes described herein. Examples of metal oxides include, but are not limited to, lithium-containing oxides, aluminum oxide, titanium oxide, manganese oxide, iron oxide, zirconium oxide, indium oxide, tin oxide, antimony oxide, bismuth oxide, or any combination thereof. Optionally, the oxide may be in the form of AMO. As described herein, the metal oxide optionally comprises and / or is surface-functionalized with one or more electron-withdrawing groups selected from Cl, Br, BO3, SO4, PO4, NO3, CH3COO, CO4, C2H2O4, C6H8O7, or C6H5O7. Examples of conductive materials include one or more of graphite, conductive carbon, carbon black, Ketjen black, or poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene. Examples of suitable conductive polymers include polyphenylene sulfonate (PSS), PEDOT:PSS composites, polyaniline (PANI), or polypyrrole (PPY).

[0024] In various embodiments, a high-capacity battery cell includes a first electrode comprising an acidified metal oxide (AMO) nanomaterial, a conductive material, and a binder; a second electrode; and an electrolyte disposed between the first electrode and the second electrode, wherein the AMO nanomaterial comprises 5-15, 20-35, or 55-70 weight percent of the first electrode; the AMO nanomaterial comprises 0-15 wt % iron oxide and 85-100 wt % tin oxide; the AMO nanomaterial comprises one or more electron-withdrawing groups and / or is surface-functionalized with one or more electron-withdrawing groups; the conductive material comprises one or more of graphite, conductive carbon, carbon black, Ketjen black, and a conductive polymer such as poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS), PEDOT:PSS composite, polyaniline (PANI), or polypyrrole (PPY); and the second electrode comprises or includes metallic lithium. Such high-capacity battery cells may exhibit a cycle life of 100-1000 charge / discharge cycles without failure and an open-circuit voltage upon assembly between 2 V and 4 V. Optionally, the first electrode may comprise a layered structure including a first set of layers including a conductive material and a second set of layers including an AMO nanomaterial, the first set of layers and the second set of layers being provided in an alternating configuration, the first set of layers including between 1 and 20 layers, the second set of layers including between 1 and 20 layers, the first set of layers and the second set of layers independently having thicknesses between 1 μm and 50 μm, and the AMO nanomaterial may comprise between 5 and 70 weight percent of the second set of layers.

[0025] 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 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 optionally, 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 contain 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 exhibit its own acidity, e.g., having a pH of less than 7 (but not very acidic) when suspended in water at 5 wt % (or resuspended in water after drying).

[0026] Various techniques can be used to prepare the metal oxide. Optionally, the step of preparing the metal oxide includes 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 base to the solution, collecting a precipitate from the solution, washing the precipitate, and drying the precipitate.

[0027] Optionally, fabricating the electrode may further include depositing an additional conductive layer on the electrode layer, such as a conductive layer comprising a second conductive material. Optionally, depositing the conductive layer may include forming a conductive slurry using the second conductive material, a second binder, and a second solvent, depositing the conductive slurry layer on the electrode layer, and evaporating at least a portion of the second solvent to form the conductive layer. Optionally, fabricating the electrode may include forming 1 to 20 additional conductive layers comprising a conductive material and 1 to 20 additional electrode layers comprising a metal oxide. For example, the electrode may include a layered structure including a first set of layers comprising the second conductive material and a second set of layers comprising a metal oxide. The first set of layers and the second set of layers are provided in an alternating configuration. Exemplary layers include layers independently having a thickness between 1 μm and 50 μm. Exemplary layers include layers including between 10 and 90 weight percent metal oxide. Exemplary layers include layers independently including between 5 and 85 weight percent conductive material and / or binder.

[0028] Electrodes formed using the method of this embodiment may have a metal oxide content of up to 80 weight percent. Electrodes formed using the method of this embodiment may have a conductive material and / or binder content of between 10 and 70 weight percent of the electrode.

[0029] 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 impregnated or permeated into the pores of the electrodes and / or the pores of any material or structure that may optionally be disposed between the electrodes, such as a separator.

[0030] 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

[0031] [ka]

[0032] 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:

[0033] [ka]

[0034] 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

[0035] [ka]

[0036] 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.

[0037] 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. %.

[0038] 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).

[0039] 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.

[0040] 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. Optionally, the conductive additive may be present in the electrode at a concentration of 1 wt % to 95 wt %. %, 1% to 35% by weight, 1% to 25% by weight, 5% to 40% by weight, 10% to 40% by weight, 15% to 40% by weight, 20% to 40% by weight, 25% to 40% by weight, 30% to 40% by weight, 35% to 40% by weight, 40% to 45% by weight, 40% to 50% by weight, 40% to 55% by weight, 40% to 60% by weight, 40% to 65% by weight, 40% to 70% by weight, 40% to 75% by weight, 40% to 80% by weight, 40% to 85% by weight, 40% to 90% by weight, or 40% to 95% by weight.

[0041] Methods of making batteries are also described herein. Exemplary methods of making batteries include making AMO nanomaterials and connecting a first electrode of AMO nanomaterials or a first electrode including AMO nanomaterials. Another example of a method of battery construction includes forming a first electrode, forming an electrolyte by dissolving one or more metal salts in a solvent, and disposing the electrolyte between a first electrode and a second electrode. Another example of a method of battery construction includes forming 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.

[0042] 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, may be dissolved in the solvent.

[0043] 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.

[0044] 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. The example solvents may be useful in metal ion batteries, such as lithium ion batteries. [Brief explanation of the drawings]

[0045] [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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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 including electrodes that include 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. [Figure 47] 1 is a plot of temperature and voltage for a cell constructed in accordance with the present disclosure and subjected to a nail penetration test. [Figure 48A] 1 is a plot of temperature and voltage of a cell constructed in accordance with the present disclosure and subjected to an overcharge test. [Figure 48B] FIG. 48B is a plot of the overcharge test of FIG. 48A focusing on the start of the test. [Figure 49] FIG. 2 is a side view of an exemplary cathode according to aspects of the present disclosure.

[0046] definition For purposes of this disclosure, the following terms have the following meanings:

[0047] 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.

[0048] 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.

[0049] Acidic - A term commonly used in the scientific literature to refer to compounds that have a pH of less than 7 in aqueous solution.

[0050] 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.

[0051] 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. The value of H0 = -12 for pure sulfuric acid should not be interpreted as a pH of -12, but rather it indicates that the acid species present has a pH of 10 as measured by its ability to protonate 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 is based on the results of colorimetric reagent tests and temperature-programmed desorption. It can be correlated.

[0052] 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.

[0053] Monodisperse--characterized by particles of uniform size that are substantially separate from one another and not agglomerated into grains of larger particles.

[0054] 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.

[0055] Surface functionalization - The attachment of small atomic or molecular groups to the surface of a material.

[0056] Superacid - A substance that is more acidic than 100% H2SO4 and has a Hammett function of H0<-12. DETAILED DESCRIPTION OF THE INVENTION

[0057] High-capacity electrochemical cells and cell components, such as electrodes for such cells, are described herein. The disclosed electrochemical cells and electrodes comprise acidified metal oxide ("AMO") nanomaterials and exhibit high capacities. In embodiments, the AMO nanomaterials are provided at relatively low weight percent loadings in the electrode, such as less than 30% weight percent, with the majority of the remainder of the electrode comprising conductive materials and binders. Even at these low loadings, capacities exceeding 10,000 mAh / g of AMO nanomaterial have been observed. The electrodes may be provided in layered or non-layered configurations. Examples of layered configurations include individual layers containing AMO nanomaterials and layers with low loadings or no AMO. However, electrode layering is entirely optional, and high capacities have been observed in both layered and non-layered electrodes.

[0058] 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.

[0059] 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.

[0060] 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 lithium-based electrolyte / solvent combinations known in the art may also be used. In some cases, the electrolyte 108 can 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.

[0061] 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 .

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] 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, which in turn improves its ability to absorb lithium ions during discharge and results in an overall improved 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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 either 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.

[0072] 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, thermal 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.

[0073] 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 are suitable for use in forming 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.

[0074] 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 metallic lithium anodes.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] The quantity and strength of Lewis acid and Lewis base sites (from exposed metal cations and oxygen anions, respectively) and Bronsted acid and Bronsted base sites (from surface hydroxyl groups) add a wide range of utility and functionality to metal oxides, making them suitable for chemical applications. Adding to the use of metal oxides in both reactions and device applications, these points contribute significantly to the chemical reactivity of metal oxides. They can serve as anchoring points to which other chemical groups, even additional metal oxides, can bind. They can also influence surface charge, hydrophilicity, and biocompatibility.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 2. Stir the resulting solution for 30 minutes.

[0087] 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.

[0088] The solution is basified by adding 4.1 M aqueous base dropwise until the pH of the solution is about 8.5.

[0089] 5. The resulting opaque white suspension is then placed in a water bath (approximately 60-90°C) with stirring for at least 2 hours.

[0090] 6. The suspension is then washed with distilled water and then with absolute ethanol.

[0091] 7. The washed suspension is dried in air at 100°C for 1 hour and then annealed in air at 200°C 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.

[0092] 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:

[0093] [Table 1]

[0094] In some embodiments, the electron withdrawing group has a carbon chain length of 6 or less and / or an organic mass (AMU) of 200 or less. having a carbon chain length of 10 or less and / or an organic mass of 500 or less.

[0095] It will be understood that the parameters of this method can be varied. These parameters include, but are 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, the number and type of washing steps, the time and temperature of drying and calcination, and exposure to gas during drying and calcination. Variations may be performed alone or in any combination, optionally using experimental design techniques. Additionally, other metal oxide synthesis methods—e.g., 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.

[0096] 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).

[0097] 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).

[0098] 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.

[0099] 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.

[0100] 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.

[0101] An exemplary AMO is acidified tin oxide (Sn x O y ), acidified titanium dioxide (Ti a O b ), acidified iron oxide (Fe c O d ), and acidified zirconium oxide (Zr e O f ). Exemplary electron-withdrawing groups ("EWGs") are Cl, Br, BO3, SO4, PO4, and CH3COO. 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 H0 > -12, at least on its surface.

[0102] 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.

[0103] To maximize the amount of total available surface area, the AMOs should be in nanoparticulate form (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 10 nm in size.

[0104] 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 M m 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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).

[0114] 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).

[0115] 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 (see Figure 13). This is contrary to what the prior art teaches.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] Various layering and other strengthening techniques may be deployed to maximize the ability to retain lithium ions to power the cell 100. It should also be understood that the cell can be deployed as a secondary (e.g., rechargeable) battery, but can also function as a primary battery. While the AMO anodes of the present disclosure are suitable for reversible battery chemistries, cells or batteries constructed as described herein may be fully deployed as primary cells or batteries.

[0120] In the battery industry, the term "formation" is used to refer to the initial charging or discharging of a battery that occurs at a manufacturing facility before the battery is ready for use. The formation process is generally very slow and may require multiple cycles aimed at converting the as-manufactured active material into a form more accessible to the cell cycle. These transformations may be changes in the structure, morphology, crystallinity, and / or stoichiometry of the active material.

[0121] Cells and batteries constructed according to the present disclosure, in some embodiments, do not require initial formation and thus can be used immediately as primary cells or batteries. In other cases, limited formation or rapid formation may be used. Furthermore, by deploying the cells and batteries of the present disclosure as primary batteries that are not intended to be recharged, some of the safety issues believed to be inherent in lithium battery chemistry are mitigated, although safety issues are known in the art to arise more frequently during battery cycling. However, after the initial primary discharge, the cells and batteries disclosed herein are optionally suitable for use as secondary battery systems that may undergo many charge-discharge cycles, such as up to tens, hundreds, or even thousands of cycles.

[0122] In other embodiments according to the present disclosure, the cathode 104 includes nanoparticles of tin oxide (SnO), which are 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.

[0123] 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.

[0124] It will be appreciated that the AMO materials disclosed herein may be added as dopants to the anode and / or cathode of conventional lithium-ion cells in amounts between 0.01% and 10% by weight of the AMO material in the electrode, or, for example, in amounts of about 1%, 5%, or 10% by weight. The disclosed AMO materials provide a surprising capacity for storing lithium atoms, and adding these materials to conventional lithium-ion cell electrodes provides these composite capabilities. In one specific example, the electrode includes LiCoO2 and AMO. In another example, the electrode includes a carbonaceous material, such as graphite, and AMO.

[0125] The AMO materials of the present disclosure may optionally be used with an acidic component, such as a binder, an acidic electrolyte, or an acidic electrolyte additive. The AMO materials of the present disclosure may be in association with an anode, a cathode, a half cell, a complete cell, a monolithic battery, or other component. The inventors have surprisingly found that batteries containing AMO materials can be used without the addition of an acidic component, such as an organic acid or anhydride. It has been found that the inclusion of components and / or acidic species increases the capacity compared to batteries that do not contain the acidic species. Again, the prior art teaches against the use of acidic species because these species can degrade metal current collectors and housings and cause degradation of other electrode components.

[0126] 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.

[0127] 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.

[0128] Several acidic electrolytes have been developed and / or tested and found to work advantageously in the cell chemistries described herein. [Example]

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] Example 5 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 citric acid (CHO). 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 cycled by discharging to zero volts and subsequently charging to 1.5 volts. Figure 20 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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 dissolved in an ethanol / water solution containing a small amount of iron acetate (Fe(CH3COO)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.

[0139] 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.

[0140] Example 12 Iron oxide-doped, acetate / citrate-functionalized tin oxide AMOs Doped tin oxide was synthesized using a single-pot hydrothermal 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 citric acid (C6H8O7). The resulting material was a yellow, glassy, ​​hard material without particle formation, 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 27 shows the structure of the AMO nanoparticles. Electron microscope images of the material, a plot of the measured capacity versus cycle number, and a plot of the voltage as a function of time during cycling are shown.

[0141] 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.

[0142] 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.

[0143] Example 15 AMO of tin oxide doped with manganese oxide and functionalized with sulfate / chloride 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.

[0144] 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.

[0145] Example 17 AMOs of tin oxide doped with iron oxide and aluminum oxide and functionalized with chloride Two doped tin oxide AMO samples were prepared using a single-pot hydrothermal synthesis method. The AMO nanomaterial was synthesized. 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 first sample of AMO nanomaterial was a light tan, flake-like 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 32 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. The resulting second sample of AMO nanomaterial was a light gray, flake-like material.

[0146] 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.

[0147] 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 adding hydrochloric acid (HCl). 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 34 shows a plot of the measured capacity versus cycle number and a plot of the voltage as a function of time during cycling.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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 39 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.

[0153] Example 25 Chloride-functionalized indium oxide AMO 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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(CHCOO)) and iron chloride (FeCl) were dissolved in an ethanol / water solution containing a small amount of tin chloride (SnCl). The solution was acidified by the addition of hydrochloric acid (HCl). During the synthesis, a tan-pinkish color with a green ring developed in the flask. However, the final AMO nanomaterial was gray 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 4 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.

[0158] 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.

[0159] 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(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). The resulting AMO nanomaterials were characterized by a thin milky white color. The white material was formed into an electrode. 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 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.

[0160] Currently, lithium batteries are recognized as a safety risk in certain circumstances. For example, airline regulations now require partial discharge of lithium batteries carried in cargo holds. Fires resulting from runaway exothermic reactions have been reported in devices using lithium batteries. Furthermore, lithium fires can be difficult to extinguish using commonly deployed fire suppression systems and equipment. For these reasons, lithium-containing compounds, rather than metallic lithium, are used in many commercial battery cells.

[0161] However, using a lithium-containing compound rather than lithium metal in the anode may limit the amount of lithium available to react and absorb into the cathode during discharge, thus limiting the capacity of such cells. However, the AMO materials disclosed herein not only absorb more lithium during discharge, but also demonstrate improved safety characteristics. For example, when battery cells containing AMO materials in the cathode and lithium metal electrode are subjected to safety tests such as nail penetration tests, short-circuit tests, and overvoltage tests, the batteries perform well and do not appear to pose an unacceptable risk of fire or explosion. This may be because the AMO passivates the lithium metal in the cell or battery. Even when using solid or pure lithium as the anode, devices using the AMO of the present disclosure as the cathode do not appear to pose an unacceptable risk of fire or explosion. The novel safety results may also be due to the lower operating voltage of cells constructed according to the present disclosure, which, in some embodiments, is <1.5 V compared to conventional lithium-ion operating voltages of >3.0 V.

[0162] Several cells were constructed with cathodes containing AMO(SnO2) according to the present disclosure. The cathodes were prepared from a composition of AMO(SnO2), Ketjen Black (KB), polyvinylidene fluoride (PVDF), and polyarylamide (PAA) in a volume ratio of 63 / 10 / 26.1 / 0.9. Double-sided layers of this composition were applied at 4 mg / cm2 per side. 2Six of these layers constituted the cathode. The area of ​​the prepared cathode was 9 × 4 cm. 2 The separator was obtained from Targray Technology International, Inc. and contained a 25 μm thick polypropylene layer. The separator area was 9.4 × 4.4 cm 2 The electrolyte was prepared from 1 M LiPF in a solvent of ethylene carbonate, diethyl carbonate, and dimethyl carbonate in a 1 / 1 / 1 volume ratio. The anode had an area of ​​9.2 × 4.2 cm. 2 , a 50 μm thick layer of lithium metal.

[0163] Two of the constructed cells were discharged prior to safety testing and the actual capacity of these cells was found to be 1.7 Ah and the specific capacity was 1575 mAh / g SnO2.

[0164] Figure 47 is a plot of the temperature and voltage of a cell constructed as described above and subjected to a nail penetration test. The test was performed at room temperature and no events (such as fire) were observed. It can also be seen that the temperature and voltage remain stable.

[0165] Figure 48A is a plot of the temperature and voltage of a cell constructed as described above and subjected to an overcharge test. A current of 1 A was applied. No adverse events were observed over the test period, except for gas evolution from the cell. Figure 48B is a plot of the overcharge test of Figure 48A, focusing on the beginning of the test.

[0166] It should be understood that the examples constructed for penetration testing purposes are not intended to be limiting with respect to the entire disclosure herein. Cells and batteries of various sizes, capacities, and materials may be constructed in accordance with the present disclosure. Utilizing the AMOs of the present disclosure, such batteries will benefit from the improved safety demonstrated herein, regardless of whether such safety is ultimately due to lithium passivation, low voltage, or other factors.

[0167] Embodiments of electrochemical cells constructed incorporating AMO materials as cathodes and lithium as electrodes have been tested to successfully undergo up to 900 or more charge-discharge cycles without catastrophic, destructive failure. In other words, embodiments of electrochemical cells constructed incorporating AMO materials as cathodes and lithium as electrodes have been tested to successfully undergo up to 900 or more charge-discharge cycles and still retain a charge and maintain useful capacity.

[0168] Without wishing to be bound by any theory, the improved safety provided by the use of AMO-based cathode materials in lithium batteries may result from the ability of the AMO materials to passivate metallic lithium and prevent dendrite formation. The inventors observed that upon cycling, metallic lithium anodes did not appear to grow or form dendrites, but rather exhibited a softer, less crystalline structure. In some embodiments, metallic lithium anodes may be passivated, such as by cycling, as components of the electrochemical cells described herein, and then removed from the electrochemical cell and used as electrodes in a new electrochemical cell with a different cathode. Additionally, cells constructed according to the present disclosure utilize low operating voltages, such as between 1 and 2 volts, which contrasts with the typical voltages of lithium or lithium-ion battery cells, which typically operate at about 3 to 4.2 volts. This difference in operating voltage may partially explain the safety of the disclosed cells.

[0169] Regarding cell or battery constructions using lithium as the anode according to the present disclosure, in some embodiments, the entire anode (100%) is metallic lithium. The metallic lithium need only be substantially pure, in that a small percentage of the anode may contain trace elements and impurities that do not measurably affect the performance of the cell or battery. In various embodiments, the anode comprises at least 50%, 55%, 60%, 65%, 75%, 80%, 85%, 90%, or 95% metallic lithium.

[0170] For purposes of this disclosure, the term "metallic lithium" refers to lithium in its neutral atomic state (i.e., non-ionic state). The term metallic lithium is intended to distinguish it from other forms of lithium, including lithium ions and lithium compounds. The term metallic lithium may refer to neutral atomic lithium present in a mixture containing lithium atoms, such as a mixture of lithium and other elements, compounds, or substances. The term metallic lithium may refer to neutral atomic lithium present in a lithium alloy, such as a metal mixture containing lithium and one or more other metals. The term metallic lithium may refer to neutral atomic lithium present in a composite structure containing lithium and one or more other materials. It will be understood that an electrode comprising or including metallic lithium may contain other materials in addition to lithium, although metallic lithium may correspond to the active material of such an electrode. In some cases, the anode of an electrochemical cell comprises metallic lithium.

[0171] For purposes of this disclosure, metallic lithium may be interpreted to mean lithium that has not reacted with other elements to form compounds (at least during construction of the battery or cell). In some embodiments, a portion of the anode may be metallic lithium and a portion of the anode may be a lithium compound containing various percentages of lithium that have reacted with other elements to form lithium compounds. The metallic lithium may be arranged on or within the anode so as to be geometrically separated from the lithium compound portion of the anode.

[0172] Referring now to FIG. 49, a perspective view of a cathode 1800 according to an embodiment of the present disclosure is shown. FIG. 49 is not to scale. Cathode 1800 comprises 33.3% SnO in the form of AMO. AMO was prepared according to the method described above. Ketjenblack EC-300J (SA: ∼800 ml) was dissolved in NMP solvent. 2A slurry of 80 wt % Ketjen Black and 20 wt % PVDF was prepared and coated on a 10 μm thick copper foil 1802 to form a carbon layer 1804. The slurry composition was 80 wt % Ketjen Black and 20 wt % PVDF. The coated tape was dried in a vacuum oven at 100°C.

[0173] SnO2 (AMO), Ketjen black, and PVDF were mixed at 33.3 wt% each and NMP solvent was added to prepare a slurry, which was then coated onto a portion of Ketjen black-coated copper foil (1802, 1804) to form a carbon / SnO2 layer 1806. The resulting tape was dried in a vacuum oven at 100°C (overnight) and calendered at room temperature. The thickness of the tape was measured using a micrometer in the SnO2-coated area and the Ketjen black (only)-coated area. The Ketjen black layer 1804 was approximately 8 μm thick, and the electrode layer 1806 was approximately 2 μm thick. The foil layer 1802 was approximately 10 μm thick, giving a total thickness of the cathode 1800 of approximately 18 μm.

[0174] The calendered tape was punched into circular disks in the Ketjenblack (only) and SnO2-coated areas. The weight of the Ketjenblack disk was subtracted from the SnO2 disk to determine the total mass of the electrode material. For one cell type tested, the total mass of the electrode material was 0.0005 g (after subtracting the Ketjenblack disk weight), and the active material content was 0.000167 g (33.3% of the total mass).

[0175] Several key elements of cathode 1700 are (1) layering using a carbon undercoat, (2) the use of Ketjenblack high surface area carbon in both the undercoat and topcoat, (3) a 33% active material topcoat, and (4) a thin (approximately 2 μm) topcoat layer. All of these parameters can be further developed.

[0176] In some embodiments, carbons other than Ketjenblack are used. Binders other than PVDF may be used. The cathode may be constructed of one or more layers. The percentage of active material may be greater than or less than 33%. The thickness of one or more layers may be greater than or less than 2 um. Various current collectors may be used to optimize the cell structure.

[0177] It should be understood that the above example provides one example of an active material loading in an electrode lower than previously believed to promote optimal performance and capacity. As previously mentioned, conventional preferences for active material loading are 90%, 95%, or even higher if possible. According to this embodiment, the active material loading may be less than 80% w / w. In some embodiments, the calculation of the active material loading percentage may be the total active material loading, including the various conductive layers of the electrode. For example, a layer having a higher active material loading of 33% (but still low according to prior art teachings) combined with a conductive layer containing little or no active material may provide 23% of the total active material loading of the entire electrode. In various embodiments, the total active material loading of the electrode is less than 63%. In another embodiment, the active material loading is between 23% and 33% in total. In yet another embodiment, the active material loading is between 11% and 14% in total.

[0178] All references throughout this application, including, for example, patent documents, including issued or granted patents or equivalents, patent application publications, and non-patent literature documents, or other materials, are hereby incorporated by reference. No. 6,277,793, filed Dec. 1, 2004, and entitled "Patent Document 1: Application No. 10 / 109,497, filed Dec. 1, 2004," which is incorporated herein by reference in its entirety as if individually incorporated.

[0179] 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.

[0180] 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 equivalent to "1" or "2" or "3," or "1 and 2" or "1 and 3" or "2 and 3," or "1, 2, and 3."

[0181] 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.

[0182] 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.

[0183] The terms and expressions which have been used 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 invention has been specifically disclosed by preferred embodiments and optional features, the invention disclosed herein may be modified in any way without departing from the spirit and scope of the invention. It is to be understood that modifications and variations of the concepts described may be possible by those skilled in the art, and such modifications and variations are considered to be within the scope of the present 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 less than 80% solid metal oxide nanomaterial comprising an acidic, but not super-acidic, surface, which, after drying, when resuspended at 5 wt. % in water, has a pH less than 5 and a Hammett function, H, greater than -12. [2] 2. The battery cell of claim 1, wherein the less than 80% solid metal oxide nanomaterial comprises less than 65% solid metal oxide nanomaterial. [3] 2. The battery cell of claim 1, wherein the less than 80% solid metal oxide nanomaterial comprises 23% to 33% solid metal oxide nanomaterial. [4] 2. The battery cell of claim 1, wherein the less than 80% solid metal oxide nanomaterial comprises 11% to 14% solid metal oxide nanomaterial. [5] 6. The battery cell of claim 1, wherein the one of the anode or cathode comprises a layered structure including a first set of layers including a conductive material and a second set of layers including the metal oxide nanomaterial, the first set of layers and the second set of layers being provided in an alternating configuration. 6. The battery cell of claim 5, wherein the first set of layers includes between 1 and 20 layers and the second set of layers includes between 1 and 20 layers. [7] 6. The battery cell of claim 5, wherein the first set of layers and the second set of layers independently have a thickness between 1 μm and 50 μm. [8] 1. A battery cell having an electrode comprising at least one active solid metal oxide material at a concentration of less than 65 wt.%, 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, the electrode comprising a layered structure comprising a first set of layers comprising a conductive material and a second set of layers comprising the metal oxide material, the first set of layers and the second set of layers being provided in an alternating configuration. [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 less than 5 when suspended at 5 wt % in an aqueous solution, and a Hammett function H greater than −12.

[11] 10. The battery cell of claim 9, wherein when the battery cell is constructed, the counter electrode comprises at least 50% metallic lithium.

[12] 12. The battery cell of claim 11, wherein the counter electrode comprises at least 95% metallic lithium when the battery cell is constructed.

[13] 10. The battery cell of claim 9, wherein when the battery cell is constructed, at least a geometric portion of the counter electrode consists essentially of metal.

[14] Less than 65% by weight of 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 xis 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, at least on its surface, when dried and resuspended at 5 wt % in water, has a pH of less than 5 and a Hammett function H of greater than -12.

[15] 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 15. The battery cell according to claim 14, including:

[16] The solid metal oxide nanomaterial constituting the cathode is a third different metal "R r 16. The battery cell according to claim 15, including:

[17] 15. The battery cell of claim 14, wherein the cathode comprises less than 33% of the solid metal oxide nanomaterial.

[18] 15. The battery cell of claim 14, wherein the cathode comprises less than 14% of the solid metal oxide nanomaterial.

[19] providing a lithium anode in the battery cell; providing in the battery cell a cathode comprising 65 wt. % or less of an active solid metal oxide nanomaterial comprising a surface that is acidic, but not superacidic, wherein the surface, after drying, when resuspended at 5 wt. % in water has a pH < 5 and a Hammett function H > -12.

[20] 20. The method of claim 19, wherein the lithium anode consists essentially of metallic lithium.

Claims

1. 1. A battery cell comprising a cathode comprising a solid metal oxide nanomaterial, wherein the metal of the solid metal oxide nanomaterial is at least one of tin, iron, manganese, and titanium, and wherein the solid metal oxide nanomaterial 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 and wherein the solid metal oxide nanomaterial is surface-functionalized with one or more electron-withdrawing groups selected from the group consisting of: and wherein the solid metal oxide nanomaterial has a pH of less than 5, wherein the pH is measured when the solid metal oxide nanomaterial is suspended in water at 5 wt %, in dry form; and wherein the solid metal oxide nanomaterial further has a Hammett function H greater than -12. ０ wherein the solid metal oxide nanomaterial comprises less than 25% by weight of the cathode when the battery cell is constructed.

2. The battery cell of claim 1 , wherein the battery cell is a lithium-ion battery cell.

3. 10. The battery cell of claim 1, wherein the solid metal oxide nanomaterial comprises less than 20% by weight of the cathode.

4. 10. The battery cell of claim 1, wherein the solid metal oxide nanomaterial comprises less than 15% by weight of the cathode.

5. 10. The battery cell of claim 1, wherein the solid metal oxide nanomaterial comprises less than 10% by weight of the cathode.

6. 10. The battery cell of claim 1, wherein the cathode comprises a layered structure including a first set of layers including a conductive material and a second set of layers including the solid metal oxide nanomaterial, the first set of layers and the second set of layers being provided in an alternating configuration.

7. 10. The battery cell of claim 1, wherein the solid metal oxide nanomaterial is a mixed metal oxide, the mixed metal oxide comprising at least two selected from the group consisting of tin, iron, manganese, and titanium.

8. 10. The battery cell of claim 1, further comprising a counter anode disposed opposite the cathode when the battery cell is constructed, the counter anode comprising at least 50% metallic lithium by weight, based on the weight of the counter anode.

9. 10. The battery cell of claim 8, wherein the counter anode comprises at least 95% metallic lithium by weight.

10. 9. The battery cell of claim 8, wherein the counter anode comprises a lithium compound, and the metallic lithium is geometrically separated on or within the counter anode from the lithium compound portion of the counter anode.

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