POWER STORAGE DEVICES USING MIXED-VALENT MANGANESE OXIDE

FIELD OF THE INVENTION

[0001] The present invention relates to metal-substituted manganese-based octahedral molecular sieves, compositions of metal-substituted manganese-based octahedral molecular sieves in combination with at least one additional component, electrodes for power storage devices, and power storage devices using metal-substituted manganese-based octahedral molecular sieves or compositions thereof.

BACKGROUND OF THE INVENTION

[0002] Zeolites and zeolite-like materials constitute a well-known family of molecular sieves. These materials are tetrahedral coordinated species with T0 ₄ tetrahedra (in which T is silicon, aluminum, phosphorus, boron, beryllium, gallium, etc.) serving as the basic structural unit. Through secondary building units, a variety of frameworks with different pore structures can be constructed. Like tetrahedra, octahedra can also serve as the basic structural units of molecular sieves.

[0003] Manganese oxide octahedral molecular sieves (OMS) possessing mono- directional tunnel structures constitute a family of molecular sieves wherein chains of Mn0 ₆ octahedra share edges to form tunnel structures of varying sizes. Such materials have been detected in samples of terrestrial origin and porous manganese oxide natural materials are also found as manganese nodules. These materials when dredged from the ocean floors have been used as excellent adsorbents of metals such as from electroplating wastes and have been shown to be excellent catalysts. The natural systems are often found as mixtures, are poorly crystalline, and have incredibly diverse compositions due to exposure to various aqueous environments in nature. Such exposure allows ion-exchange to occur.

[0004] Such materials have also been produced synthetically. Rationale for synthesis of novel OMS materials is related to the superb conductivity, mixed valency, microporosity, and catalytic activity of the natural materials. Variable pore size materials have been synthesized using structure directors and with a variety of synthetic methodologies. Transformations of tunnel materials with temperature and in specific atmospheres have recently been studied with in situ synchrotron methods. Conductivities of these materials appear to be related to the structural properties of these systems with more open structures being less conductive. Catalytic properties of these OMS materials have been shown to be related to the redox cycling of various oxidations states of manganese such as Mn ²⁺ , Mn ³⁺ , and Mn ⁴⁺ .

SUMMARY OF THE INVENTION

[0005] In an embodiment of the invention, a manganese-based octahedral molecular sieve includes a framework substitution with at least one substituting metal. The substituting metal can be, for example, lithium (Li), sodium (Na), silver (Ag), copper (Cu), or a combination of vanadium (V) and copper (Cu). The substituting metal can be, for example, silver (Ag), gold (Au), iron (Fe), copper (Cu), cobalt (Co), nickel (Ni), scandium (Sc), titanium (Ti), zinc (Zn), or a combination of these, or a combination of any one of these with vanadium.

[0006] For example, the manganese-based octahedral molecular sieve can have a 2x2,

3x2, 3x3, 3x4, 3x5, or 4x4 tunnel structure. For example, the molar amount of each at least one substituting metal divided by the molar amount of manganese can be in a range of from about 0.0001% to about 40%, can be in a range of from about 1% to about 10%, or can be about 1%. For example, the molar amount of vanadium can be about 1% of the molar amount of manganese and the molar amount of copper can be about 1% of the molar amount of manganese. For example, a manganese-based octahedral molecular sieve can have a rod-like morphology, with rods having a length in the range of from about 100 nm to about 500 nm and a diameter in the range of from about 10 nm to about 20 nm.

[0007] In an embodiment of the invention, a composition can include a manganese- based octahedral molecular sieve and at least one of a polymer binder, carbon material, carbon nanomaterial, and/or silicon nanomaterial. For example, the composition can include a polymer binder, graphite, and a carbon material. For example, the polymer binder can be a polyvinylidene fluoride polymer, the carbon material can be graphite and/or conductive carbon black, and the carbon nanomaterial can be a nanotube, nanofiber, or fullerene. For example, the manganese-based octahedral molecular sieve can be l%V-Cu-OMS-2. For example, the manganese-based octahedral molecular sieve can be from about 10 wt% to about 99 wt% of the composition. For example, the manganese-based octahedral molecular sieve can be about 60 wt% of the composition. For example, the discharge capacity of the composition can be at least about 174 mAh/g, at least about 170 mAh/g, at least about 130 mAh/g, at least about 105 mAh/g, or at least about 60 mAh/g. For example, the discharge capacity of the composition can be at least about 0.15 mAh-cm ^"2 .

[0008] In an embodiment of the invention, an electrode for a battery can include a manganese-based octahedral molecular sieve or a composition including a manganese-based octahedral molecular sieve. The electrode can include a charge collector.

[0009] In an embodiment of the invention, a charge storage device can include a first electrode, a second electrode, and an electrolyte between the first and second electrode. The charge storage device can be a lithium-ion battery, a lithium-air battery, or a lithium-02 battery. For example, the charge storage device can include a cathode including or essentially only including l%V-Cu-OMS-2, polyvinylidene fluoride, graphite, and carbon, a metallic lithium anode, and an electrolyte including or essentially only including lithium hexafluorophosphate dissolved in a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate. For example, the reversibility of electrical capacity from the first discharge to the charge cycle of the charge storage device can be at least about 85.9%.

[0010] A method of the invention includes providing a manganese solution, heating the manganese solution at about 200 °C to form a precipitate of manganese-based octahedral molecular sieve, washing the precipitate of manganese-based octahedral molecular sieve, and drying the precipitate to yield a manganese-based octahedral molecular sieve. The manganese solution can include, essentially only include, or be manganese sulfate, potassium sulfate, and potassium persulfate dissolved in water. A dopant precursor can be added to the manganese solution. Silver (Ag), gold (Au), iron (Fe), copper (Cu), chromium (Cr), cobalt (Co), zinc (Zn), vanadium (V), titanium (Ti), nickel (Ni), scandium (Sc), lithium (Li), sodium (Na), or combinations of these can be added to the manganese solution as pure element(s), as compound(s), or as combinations of pure element(s) and compound(s). For example, sodium orthovanadate and/or cupric sulfate can be added to the manganese solution.

[001 1] A method of making an electrode of the invention includes preparing a slurry from a manganese-based octahedral molecular sieve and at least one of a binder, graphite, carbon, and a solvent, spreading the slurry as a coating onto a metal foil, evaporating the solvent from the coated foil, for example, by drying the coated foil at a temperature of, e.g., about

1 10 °C, and punching or cutting the coated foil into a desired shape to form the electrode. For example, the manganese-based octahedral molecular sieve can include or be l%V-Cu-OMS-2, the binder can include, essentially only include, or be polyvinylidene fluoride, graphite, carbon, and N-methyl-2-pyrrolidone, and the metal foil can include or be aluminum foil.

[0012] A method of making a charge storage device of the invention includes providing a cathode, providing a metallic anode, providing an electrolyte, and assembling the cathode, metallic anode, and electrolyte as the charge storage device. For example, the metallic anode can essentially only include or be metallic lithium. For example, the electrolyte can essentially only include or be lithium hexafluorophosphate dissolved in a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is (a) a 2D (two-dimensional), and (b) 3D (three-dimensional) representation of the crystal structure of OMS-2 materials.

[0014] Figure 2 shows (a) the X-ray diffraction (XRD) pattern for the as-synthesized

Ag-OMS-2 product, (b) the field emission scanning electron microscopy (FE-SEM) image of Ag-OMS-2, and (c), (d), and (e) transmission electron microscopy images.

[0015] Figure 3 shows X-ray diffraction (XRD) patterns of (a) OMS-2, (b) l%V-Cu-

OMS-2, (c) 2%V-Cu-OMS-2, (d) 5%V-Cu-OMS-2, and (e) 10%V-Cu-OMS-2.

[0016] Figure 4 shows a FE-SEM image of the OMS materials with different incorporation amounts of V and Cu for (a) pure OMS-2, (b) OMS-2 at high magnification, (c) l%V-Cu-OMS-2, (d) 2%V-Cu-OMS-2, (e) 5%V-Cu-OMS-2, and (f) 10%V-Cu-OMS-2.

[0017] Figure 5 shows a representation of an OMS-2 sample disk and a schematic plot for 4-probe resistivity measurements.

[0018] Figure 6 shows resistivities of OMS-2 and doped OMS-2 materials.

[0019] Figure 7 shows a discharge profile for Ag-OMS-2 materials in Li-0 ₂ batteries with an initial open-circuit test of 2 h (hours).

[0020] Figure 8 shows the specific discharge capacity of different OMS-2 samples.

[0021 ] Figure 9 shows discharge curves for different OMS-2 materials.

[0022] Figure 10 shows curves for charge and discharge cycling of l%V-Cu-OMS-2 materials.

[0023] Figure 1 1 shows XRD patterns of LiMnO _x materials having an OMS-2 structure.

[0024] Figures 12A and 12B show scanning electron microscopy (SEM) images of LiMnOx materials.

[0025] Figure 13 shows current density curves for Na-OMS-5 and Ag-OMS-2 materials.

[0026] Figure 14 is a representation of coin half-cells.

[0027] Figure 15 is a flowchart of a process for incorporating materials in an embodiment of the present invention into an electrode for a battery.

[0028] Figure 16A shows charge and discharge curves.

[0029] Figure 16B shows the discharge capacity of nanostructured LiMnO _x over several cycles.

[0030] Figure 17 shows the discharge capacity of nanostructured LiMnO _x over several cycles.

[0031] Figure 18 shows the discharge profile of Na-OMS-5.

[0032] Figure 19 shows the discharge profile of Ag-OMS-2.

[0033] Figure 20 illustrates various tunnel structures.

DETAILED DESCRIPTION

[0034] This application claims the benefit of U.S. Provisional Application number

61/695,357, filed August 31, 2013, which is hereby incorporated by reference in its entirety. All documents cited herein are hereby incorporated by reference in their entirety.

[0035] Embodiments of the invention include electrodes for a battery using manganese- based octahedral molecular sieves, or compositions thereof. Other embodiments include charge storage devices where at least one electrode uses manganese-based octahedral molecular sieves. The charge storage device may be, for example, a battery, such as a lithium-ion battery, lithium- air battery, or lithium-0 ₂ battery. Manganese-based octahedral molecular sieves (OMS)

[0036] Some embodiments of the invention include manganese-based octahedral molecular sieves having a framework substitution with at least one substituting metal, wherein the substituting metal is silver (Ag), gold (Au), iron (Fe), copper (Cu), chromium (Cr), cobalt (Co), zinc (Zn), vanadium (V), titanium (Ti), nickel (Ni), scandium (Sc), or combinations thereof, or combinations of one of the above substituting metals with vanadium (V). In some embodiments, the substituting metal is a combination of vanadium and copper. Some embodiments include manganese-based octahedral molecular sieves having a framework substitution with a substituting metal selected from lithium (Li), sodium (Na), or combinations thereof, or combinations of lithium (Li) and/or sodium (Na) with one or more of the above substituting metals. Embodiments also include manganese-based octahedral molecular sieves with lithium or sodium counterions or a combination of these.

[0037] Embodiments also include manganese-based octahedral molecular sieves with lithium or sodium counterions having a framework substitution with at least one substituting metal, wherein the substituting metal is silver (Ag), gold (Au), iron (Fe) copper (Cu), chromium (Cr), cobalt (Co), zinc (Zn), nickel (Ni) or combinations thereof, or combinations of one of the above substituting metals with vanadium (V).

[0038] In some embodiments, the manganese-based octahedral molecular sieves (OMS) are synthetic. In other words, they are not naturally occurring. Manganese-based octahedral molecular sieve(s) (OMS) constitute an example class of molecular sieves. These materials have one-dimensional tunnel structures and unlike zeolites, which have tetrahedrally coordinated species serving as the basic structural unit, these materials are based on six-coordinate manganese surrounded by an octahedral array of anions (e.g., oxide). The OMS framework architecture is dictated by the type of aggregation (e.g., corner-sharing, edge-sharing, or face- sharing) of the Μηθ _ό octahedra. The ability of manganese to adopt multiple oxidation states and of the Μηθ _ό octahedra to aggregate in different arrangements affords the formation of a large variety of OMS structures.

[0039] In some embodiments, the OMS further comprises an additional transition metal within the molecular framework, where the metal is silver (Ag), gold (Au), iron (Fe), copper

(Cu), chromium (Cr), cobalt (Co), zinc (Zn), nickel (Ni), or combinations thereof, or combinations of one of the above substituting metals with vanadium (V), as long as the incorporation of the additional transition metal does not collapse the one-dimensional tunnel structure. According to the present invention, a portion of the framework manganese of the manganese oxide octahedral molecular sieves is replaced with the one or more framework- substituting metal cations M ⁺ⁿ (where n indicates an oxidation state which is stable in solution). In addition to the above metals, other transition metals may be incorporated in combination with the substituting metal. Suitable additional metals include, e.g., a transition metal, for example from Groups IB, IIB and VIII of the Periodic Table of the elements, lanthanum, iridium, rhodium, palladium and platinum. Examples of useful framework-substituting metals include Mg, Fe, Co, Ni, Cu, Ti, V, Cd, Mo, W, Cr, Zn, Sc, Mo, Zr, Ta, Hf, and lanthanide series metals. The hydrated larger counter cations such as potassium and barium can themselves serve as templates for crystallization and remain in the tunnel structures of some manganese oxide hydrates, particularly those of the [M]-OMS-2 structure where they may also be referred to as tunnel cations. Therefore, the counter cation can be selected to facilitate the selection, formation and stabilization of a desired product, such as the aforementioned [MJ-OMS-2 structure, or to have a lesser effect (as with the smaller cations such as sodium and magnesium) so as to allow other preferred structures to form and/or to permit template materials other than the counter ion to act on the reaction solution.

[0040] Framework substituted OMS may be prepared according to the methods described in US Patent Number 5,702,674, incorporated herein by reference in its entirety. Accordingly a general synthesis of an [M]-OMS-l material comprises the following steps: a) reacting a source of manganese cation, a source of framework-substituting metal cation and a source of permanganate anion under basic conditions to provide an [M]-OL in which [M] designates the framework-substituting metal and OL designates the manganese oxide octahedral layered material; b) exchanging the [M]-OL with a source of counter cation; and, c) heating the exchanged [M]-OL to provide the [M]-OMS-l material.

[0041] The framework-substituting metal cation should be present in the reaction mixture in a concentration effective to introduce the desired proportions of the metal(s) into the framework of the product's structure during the course of the reaction. Therefore, any suitable salt (inorganic or organic) of the selected metal(s) can be used which is sufficiently soluble provided that the anion does not interfere with the other reactants over the course of the reaction. For example, the oxides, nitrates, sulfates, perchlorates, alkoxides, acetates, and the like can be used with generally good results. Specific examples include nitrates of cobalt, nickel, copper, zinc, lanthanum or palladium, sulfates of chromium, iron, cobalt, nickel or copper, and chlorides of magnesium, cobalt, nickel, copper, zinc or cadmium. Oxides of iron and titanium may also be used. Salts of noble metals, such as titanium, gold, palladium, or platinum, or other metals, such as copper, nickel, or silver, or combinations thereof may also be used.

[0042] The amount of metal substitution may vary up to any amount of substitution as long as the incorporation of the additional transition metal does not collapse the one-dimensional tunnel structure. The amount of substitution is highly dependent on the specific cation, the coordination number of that cation, its charge, and polarizability and may vary based on the substituting metal. The amount of substitution may be varied by changing the weight ratio between manganese (Mn) and substituting metal. The amount of substitution may range, for example between about 1 ppm (0.0001%) and about 40% of the manganese in the OMS material. The amount of substitution may be, for example, greater than about 1 ppm, greater than about 5 ppm, greater than about 10 ppm, greater than about 15 ppm, greater than about 20 ppm, greater than about 50 ppm, greater than about 75 ppm, greater than about 0.01%, greater than about 0.05%, greater than 0.1%, greater than 0.5%, greater than about 1%, or greater than about 2%. The amount of substitution may be, for example, less than about 40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 12%, less than about 10%, or less than about 5%. For example, a 1% incorporation means that 1% of the total manganese atoms have been substituted by the substituting metal. The ratio between manganese and the substituting metal can be adjusting by adjusting the concentration of the metal cation sources used to prepare the OMS material.

[0043] In some embodiments, the framework-substituted OMS. material may be prepared by refluxing a metal permanganate solution in water, followed by addition of acid and a manganese (II) salt. The metal counterion in the metal permanganate is the substituting metal. For example Ag-OMS-2 may be prepared by dissolving AgMn0 ₄ in water, followed by addition of nitric acid (HN0 ₃ ), and addition of manganese (II) acetate and refluxing. The prepared OMS may be filtered and dried. A synthesis of an example material Ag-OMS-2 is described in EXAMPLE 1, below.

[0044] In other embodiments, the framework-substituted OMS may be prepared by dissolving a manganese salt, metal salt, and source of counter cation in water and heated in a sealed vessel to a temperature greater than the boiling point of water. The resulting OMS material may be isolated by filtering, washing, and drying. Synthesis of an example material V- Cu-OMS-2 is described in EXAMPLE 2, below.

[0045] The manganese cation can be supplied by manganous salts such as MnCl ₂ ,

Μ ^η (Νθ3) ₂ , MnS0 ₄ , Mn(CH ₃ COO) ₂ , etc. The permanganate anion can be supplied by permanganate salts such as Na(Mn0 ₄ ), KMn0 ₄ , Mg(Mn0 ₄ )2, Ca(Mn0 ) ₂ , Ba(Mn0 ₄ ) ₂ , NH ₄ (Mn0 ₄ ), etc. Bases which can be used to provide an alkaline reaction medium include NaOH, KOH, tetraalkyl ammonium hydroxides, and the like. The basic reaction mixture is preferably aged, e.g., for at least 1 day and more preferably for at least about 7 days prior to the exchanging step. The source of counter cation used to ion exchange the [M]-OL can be a magnesium salt, e.g., MgCl ₂ or Mg(CH ₃ COO) ₂ , or MgS0 ₄ . The conditions of heating, e.g., autoclaving, of the exchanged [M]-OL can include a temperature of from about 100,°C to about 200°C for at least about 10 hours, for example, from about 130 °C to about 170 °C from about 2 to about 5 days.

[0046] A counter cation for maintaining overall charge neutrality can be, for example, H,

Ba, K, Na, Pb, Rb, Cs, Li, Mg, Ca, Sr, Sn, Ge, Si, and the like. Any suitable salt (inorganic or organic) of the selected metal(s) can be used which is sufficiently soluble provided, of course, that the anion does not interfere with the other reactants or the course of the reaction. For example, oxides, halides, nitrates, sulfates, disulfates, perchlorates, alkoxides, acetates, and the like, can be used with generally good results.

[0047] In one embodiment, the OMS comprises materials wherein the Mn0 ₆ octahedra share edges to form double chains and the double chains share corners with adjacent double chains to form a 2x2 tunnel structure. The size of an average dimension of these tunnels is about 4.6 A. A counter cation for maintaining overall charge neutrality, such as H, Ba, K, Na, Pb, Rb, Cs, Li, Mg, Ca, Sr, Sn, Ge, Si, and the like, is present in the tunnels and is coordinated to the oxides of the double chains. The identity of the counter cation determines the mineral species or structure type. Hollandites are generally represented by the formula (M)Mn ₈ 0i ₆ , wherein M represents the counter cation and manganese is present in at least one oxidation state. Further, the formula may also include waters of hydration and is generally represented by (M) _y Mn ₈ 0] ₆ .xH ₂ 0, where y is from about 0.8 to about 1.5 and x is from about 3 to about 10. Suitable materials include hollandite (BaMn ₈ Oi ₆ ), cryptomelane (KMn80 _]6 ), manjiroite (NaMn ₈ 0i ₆ ), coronadite (PbMn ₈ Oi ₆ ), and the like, and variants of at least one of the foregoing hollandites. In one embodiment, the OMS comprises cryptomelane-type materials. In some embodiments some or all of the counter cation is K ⁺ . Herein below, we will refer to the (2x2) tunnel structure as OMS-2. The 2x2 tunnel structure, shown in 2D and 3D representations, of OMS-2 is diagrammatically depicted in Fig. 1. Unless otherwise stated, it is to be understood that an example or embodiment described as using OMS-2 or another form of octahedral molecular sieves, such as OMS-1, also comprises other forms of octahedral molecular sieves that can have a range of counter cations.

[0048] An example material, K-OMS-2, may be prepared, for example, by combining an aqueous solution of KMn0 ₄ (0.2 to 0.6 molar), an aqueous solution of MnS0 ₄ .H ₂ 0 (1.0 to 2.5 molar) and a concentrated acid such as HNO3. The aqueous solution is refluxed at 100 °C for 18- 36 hours. The product is filtered, washed and dried, typically at a temperature of 100 to 140 °C. Similar procedures are known in the literature, for example, DeGuzman et al., Chem. Mater. 1994, 6, 815-821 , which is hereby incorporated by reference in its entirety. The counter cation may be changed by using other salts of permanganate in the process or may be prepared by ion exchange.

[0049] In other embodiments, K-OMS-2 may be prepared by dissolving KMn0 ₄ in water and stirring to form a homogeneous solution. The concentration of KMn0 ₄ may be, for example, between about 0.195 and about 0.292 mol/L. The solution may then be subjected to hydrothermal treatment at a temperature between, for example, about 230 °C and about 250 °C. In some embodiments, the solution is subjected to hydrothermal treatment of a temperature of about 240 °C. The hydrothermal treatment may proceed for from about 3 to about 5 days. In some embodiments, the hydrothermal treatment proceeds for about 4 days. The resulting slurry may be washed with water to remove impurities and dried. The material can be washed with DDW to remove impurities.

[0050] In some embodiments, the OMS comprises materials wherein the Mn0 ₆ octahedra share edges to form triple chains and the triple chains share corners with adjacent triple chains to form a 3x3 tunnel structure. The size of an average dimension of these tunnels is about 6.9 A. A counter cation, for maintaining overall charge neutrality, such as K, Na, Ca, Mg, and the like, is present in the tunnels and is coordinated to the oxides of the triple chains. Todorokites are generally represented by the formula (M)Mn ₃ 0 ₇ , wherein M represents the counter cation and manganese is present in at least two oxidation states. Further, the formula may also include waters of hydration and is generally represented by (M) _y Mn 0 ₇ .xH ₂ 0, where y is from about 0.3 to about 0.5 and x is from about 3 to about 4.5. Herein below, we will refer to the (3x3) tunnel structure as OMS-1. The 3x3 tunnel structure of OMS-1 is depicted in Fig. 20, and may be prepared according to the methods described by O'Young et al. in U.S. Patent Number 5,340,562, which is hereby incorporated by reference in its entirety. The OMS-1 structure may be prepared, for example by (a) preparing a basic mixture of a manganous (Mn ⁺² ) salt, a permanganate salt and a soluble base material and having a pH of at least about 13; (b) aging said mixture at room temperature for at least 8 hours; (c) filtering and washing said aged material to render said material essentially chlorine-free; (d) ion exchanging said filtered material with a magnesium salt at room temperature for about 10 hours; and (e) filtering, washing and autoclaving said exchanged material to form the product. The manganous salt may be, for example, MnCl ₂ , Mn(N0 ₃ ) ₂ , MnS0 ₄ , or Mn(CH ₃ COO) ₂ . The permanganate salt may be, for example, Na(Mn0 ), KMn0 ₄ , CsMn0 ₄ , Mg(Mn0 ₄ ) ₂ , Ca(Mn0 ₄ ) ₂ , or Ba(Mn0 ₄ ) ₂ . The base material may be selected from the group consisting of KOH, NaOH, and tetraalkyl ammonium hydroxides. As for the magnesium salt used to ion exchange the filtered material, this salt may be, for example, MgCl ₂ , Mg(CH ₃ COO) ₂ , and MgS0 ₄ . The ion-exchanged material is autoclaved at a temperature ranging from about 100 °C to about 200 °C for at least about 10 hours or preferably at from about 130 °C to about 170 °C for about 2 to 5 days.

[0051] Illustrations of various tunnel structures are shown in Fig. 20. In additional to the

2x2 and 3x3 tunnel structures described above, the OMS may have other tunnel structures, for example, 3x2, 3x4, 3x5, 2x4, or 4x4 tunnel structures. Other tunnel structures are described, for example, in U.S. Patent Number 5,578,282, which is hereby incorporated by reference in its entirety.

[0052] In one embodiment, the OMS has an average Mn oxidation state of about 3 to about 4. Within this range the average oxidation state may be greater than or equal to about 3.2, for example, greater than or equal to about 3.3. The average oxidation state may be determined by potentiometric titration.

[0053] The OMS may be used in any form that is convenient, such as particulate, aggregate, film, or a combination thereof. In addition, the OMS may be affixed to a substrate.

[0054] A general synthesis of an [M]-OMS-2 material comprises heating a reaction mixture which includes a source of manganese cation, a source of framework-substituting metal cation, a source of counter cation and a source of permanganate anion under acidic conditions to provide the [M]-OMS-2. Suitable acids for adjusting the pH of the reaction mixture include the mineral acids, e.g., HC1, H ₂ S0 ₄ , and HN0 ₃ , and strong organic acids, such as toluene sulfonic acid and trifluoroacetic acid.

Compositions

[0055] Embodiments of the invention include compositions having a manganese-based octahedral molecular sieve, described herein, and at least one of a polymer binder, carbon material, carbon nanomaterial, and/or silicon nanomaterial. Any polymer suitable for use in power storage devices, or in electrodes for power storage devices may be used in combination with the manganese-based octahedral molecular sieves described herein.

[0056] The polymer binder may be, for example, any thermoplastic resin or thermosetting resin. In some embodiments, the polymer binder is a thermoplastic resin. The polymer binder may be, for example, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, a copolymer of tetrafluoroethylene-hexafluoropropylene (FEP), a copolymer of tetrafluoroethylene- perfluoroalkyl vinyl ether (PFA), a copolymer of vinylidene fluoride-hexafluoropropylene, a copolymer of vinylidene fluoride-chlorotrifluoroethylene, a copolymer of ethylene- tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), a copolymer of vinylidene fluoride-pentafluoropropylene, a copolymer of propylene-tetrafluoroethylene, a copolymer of ethylene-chlorotrifluoroethylene (ECTFE), a copolymer of vinylidene fluoride- hexafluoropropylene-tetrafluoroethylene, a copolymer of vinyl idene-perfluoromethyl vinyl ether-tetrafluoroethylene, a copolymer of ethylene-acrylic acid, a copolymer of ethylene- methacrylic acid, a copolymer of ethylene-methyl methacrylate, or the like. They may be used alone or one or more kinds may be used in combination. In some embodiments, the polymer binder may be polyvinylidene fluoride, such as KYNARFLEX® 2801. Other polymers suitable for use in power storage devices or batteries may also be used.

[0057] Carbon materials, as used herein, are forms of elemental carbon suitable for use in battery electrodes, and may be used singly or in combination. Examples include conductive carbon (for example Super P carbon from Comilog, SA.) or graphite (such as KS-15 graphite from Timcal) or graphene. Some embodiments include both conductive carbon and graphite. [0058] Carbon nanostructures, as used herein, include forms of elemental carbon with three-dimensional frameworks, such as fullerenes, nanotubes, and nanofibers.

[0059] Silicon nanomaterials include silicon-based materials, such as silicon nanoparticles, nanospheres, nanorods, silicon nanosheets, silicon nanotubes, and other nanostructures.

[0060] The relative amounts of manganese-based octahedral molecular sieve, polymer binder, carbon material, carbon nanomaterial, and/or silicon nanomaterial may vary, so long as the resulting composition may be formed into an electrode for a charge storage device.

[0061] The manganese-based octahedral molecular sieve may range, for example, between about 10% and about 99% of the composition. The manganese-based octahedral molecular sieve may be, for example, more than about 10%, more than about 15%, more than about 20%, more than about 25%, more than about 30%, more than about 35%, more than about 40%, or more than about 45% of the composition. The manganese-based octahedral molecular sieve may be, for example, less than about 99%, less than about 95%, less than about 90%, less than about 85%, less than about 80%, less than about 75%, or less than about 70% of the composition.

[0062] When present, the polymer binder may range between about 10% and about 90%) of the composition. For example, the polymer binder may be more than about 10%, more than about 15%, more than about 20%, or more than about 25% of the composition. The binder may be less than about 90%, less than about 80%, less than about 70%, less than about 60%, less than about 50%), or less than about 40% of the composition.

[0063] When present, the carbon material may range between about 1% and about 40% of the composition. For example, the carbon material may be more than about 1%>, more than about 2%, more than about 4%, more than about 5%, or more than about 10% of the composition. The carbon material may be less than about 40%, less than about 35%, less than about 30%), less than about 25%, less than about 20%, less than about 15%, or less than about 10% of the composition.

[0064] When present the carbon or silicon nanomaterial may range between about 1% and about 40% of the composition. For example, the carbon or silicon nanomaterial may be more than about 1%, more than about 2%, more than about 4%, more than about 5%, or more than about 10% of the composition. The carbon or silicon nanomaterial may be less than about

40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, or less than about 10% of the composition.

Electrodes

[0065] Embodiments of the invention include electrodes for charge storage devices having a manganese-based octahedral molecular sieve or a composition described herein.

[0066] In some embodiments, the electrode may include a current collector. Any current collector may be used as long as it is an electron conductive substance, which is chemically stable in a battery. For example, a foil, mesh, or sheet composed of aluminum, aluminum alloy, stainless steel, nickel, titanium, carbon, a conductive resin, or the like may be used. In some embodiments, aluminum foil or nickel mesh is used as the current collector. Here, at the surface of the foil or sheet, a layer of carbon or titanium may be furnished or an oxide layer may be formed. In addition, at the surface of the foil or sheet, concavity and convexity may be furnished, or a net, a punching sheet, a lath board, a porous substance, a foam substance, a fiber group formed substance, or the like may also be used.

[0067] In some embodiments, such as lithium-air batteries, the electrode may be an oxygen electrode with a multilayer structure. Such multilayer thin film structures could be, for example, alternating layers of various porous metal oxides and doped porous metal oxides. These multilayers could be prepared with a variety of methods including sol gel, precipitation, chemical vapor deposition, physical vapor deposition, atomic layer deposition, photochemical deposition, plasma methods, microwave methods, ultrasonic cavitation, resistive heating, sputtering, spin coating, electroless plating, electrospinning, other related techniques, and combined methods.

[0068] In embodiments where the electrode is exposed to air, the electrode may include a polymer layer on the side of the electrode exposed to the gaseous environment. Any suitable polymer may be used that is porous to air or oxygen. In some embodiments, a microporous PTFE layer is used on the side exposed to the gaseous environment.

[0069] In some embodiments, the electrode is a positive electrode. In some embodiments, the electrode is a negative electrode. In some embodiments, the electrode is an oxygen electrode. Charge Storage Devices

[0070] Embodiments include charge storage devices having a first electrode, second electrode, and electrolyte between the first and second electrodes, wherein one of the electrodes includes a manganese-based octahedral molecular sieve, composition, or electrode described herein.

[0071] In some embodiments, the charge storage device includes an electrode having a manganese-based octahedral molecular sieve or composition described herein.

[0072] Examples of the shape of a non-aqueous air battery of the present invention include, but are not particularly limited to, a coin shape, a button shape, a sheet shape, a laminate shape, a cylindrical shape, a laminar shape, and a rectangular shape. A non-aqueous air battery of the present invention may be applied as a large battery used for electric cars or the like.

[0073] The electrolyte may be, for example, a non-aqueous electrolyte solution or a nonaqueous solvent dissolved with a lithium salt.

[0074] Examples of suitable non-aqueous solvents include, for example, cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and vinylene carbonate (VC); chained carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dipropyl carbonate (DPC); aliphatic carboxylate esters such as methyl formate, methyl acetate, methyl propionate, and ethyl propionate; lactones such as gamma-butyrolactone, and gamma-valerolactone; chained ethers such as 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), and ethoxymethoxyethane (EME); cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran; dimethylsulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformamide, dioxolane, acetonitrile, propionitrile, nitromethane, ethylmonoglyme, phosphorate triester, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, l,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propane sultone, anisole, N-methyl-2-pyrrolidone; or the like may be used. They may be used alone, however, one or more kinds may be used by mixing. Among these, a mixed solvent of cyclic carbonates and chained carbonates, or a mixed solvent of cyclic carbonates, chained carbonates and aliphatic carboxylate esters can be used.

[0075] The lithium salt may be, for example, LiC10 ₄ , LiBF ₄ , LiPF ₆ , LiAlCU, LiSbF ₆ ,

LiSCN, LiCl, LiCF ₃ S0 ₃ , LiCF ₃ C0 ₂ , Li(CF ₃ S0 ₂ ) ₂ , LiAsF ₆ , LiN(CF ₃ S0 ₂ ) ₂ , LiB, ₀ Cl, ₀ , a lithium lower aliphatic carboxylate, LiCl, LiBr, Lil, chloroborane lithium, lithium tetraphenylborate, a lithium imide salt or the like. The lithium salt may be used alone or one or more kinds may be used in combination. In some embodiments, LiPF ₆ is used. Concentration of the lithium salt in the non-aqueous solvent is not especially limited, however, but the concentration may be between about 0.2 and about 2 mol/L, or between about 0.5 mol/L and about 1.5 mol/L.

[0076] Various additives may be added to the electrolyte to improve charge and discharge characteristics of a battery. As the additives, for example, triethyl phosphite, triethanol amine, cyclic ether, ethylene diamine, n-glyme, pyridine, hexaphosphoric triamide, nitrobenzene derivatives, crown ethers, quaternary ammonium salts, ethylene glycol dialkyl ethers and the like may be included.

[0077] A separator may be inserted between the first and second electrodes. As the separator, any thin microporous membrane, with high ion permeability, mechanical strength, and insulation performance may be used. As the thin microporous membrane, one having the function of blocking the pores at elevated temperature, thus increasing resistance, may be used. The material of the thin microporous membrane may be, for example, a polyolefin such as polypropylene, polyethylene, or the like, or any polymer with suitable organic solvent resistance and hydrophobicity. In addition, a sheet, non-woven fabric, woven textile, or the like prepared by glass fibers or the like may be used.

[0078] In some embodiments, the separator may be paper made of OMS materials described herein, including papers made of OMS-2 materials. Papers of OMS materials may be produced by, for example, Yuan, J.; Gomez, S.; Villegas, J.; Laubernds, K.; Suib, S. L.

Spontaneous Formation of Inorganic Paper-Like Materials, Adv. Mat., 2004, 16, 1729-1732, which is hereby incorporated by reference herein in its entirety.

[0079] In some embodiments, the other electrode may be, for example, a negative electrode. The negative electrode may be any suitable negative electrode material used in batteries. For example, zinc, lithium foil, lithium alloy, or graphite may be used. For a rechargeable zinc alkaline manganese oxide battery the negative electrode would be zinc. In some embodiments, the negative electrode is lithium foil. EXAMPLES

EXAMPLE 1

[0080] Reflux synthesis. In a typical synthesis, 3 g AgMn0 ₄ was dissolved in 80 mL Millies water (DDW), followed by adding 4 mL concentrated HN0 ₃ . The aqueous solution was further mixed dropwise with a solution containing 4.8 g manganese (II) acetate and 60 mL DDW. The mixed solution was refluxed at 100 °C for 12-20 hours under atmospheric conditions. The product was collected from the resulting slurry after the reaction was cooled in air. The product was dried at 120 °C overnight for further use. Figure 2 shows XRD patterns. Figure 2a shows the X-ray diffraction (XRD) pattern for the as-synthesized Ag-OMS-2 product. All the diffraction peaks can be indexed to a pure hollandite phase of Agl .8Mn8016 [space group: I4/m] with a tetragonal structure. Figure 2b shows the field emission scanning electron microscopy (FE-SEM) image of Ag-OMS-2. Such as-synthesized materials have fibrous morphology with a uniform diameter of 20-40 nm and a length of about several hundred nanometers. This was confirmed in Figures 2c-d providing images of transmission electron microscopy (TEM). The well-arranged lattice planes (1 10) of Ag-OMS-2 materials are clearly shown in Figure 2e.

EXAMPLE 2

[0081] Hydrothermal synthesis. 0.65 g MnS0 ₄ .H ₂ 0 (manganese sulfate), 1.046 g K ₂ S0 ₄

(potassium sulfate), and 1.62 g K ₂ S ₂ 0 ₈ (potassium persulfate) were dissolved in 13.5 mL DDW in a Teflon liner after stirring for 30 min, then the liner was transferred to a stainless-steel vessel. The vessel was sealed and placed in an oven and heated at 200 °C for 48 h. The resultant dark-brown precipitate was washed with DDW and dried at 120 °C overnight. To prepare doped OMS-2 materials, dopant precursors were added in synthesis. For example, to make 2%V-Cu-OMS-2 materials, 0.015 g Na ₃ 0 ₄ V (sodium orthovanadate), 0.021 g of CuSO ₄ .5H ₂ 0 (cupric sulfate) were added in the synthesis. That is, the 2%V-Cu-OMS-2 materials have in their composition a molar amount of vanadium that is approximately 2% of the molar amount of manganese (here, mol V / mol Mn = 0.022 = 2.2%) and a molar amount of copper that is approximately 2% of the molar amount of manganese (here, mol Cu / mol Mn = 0.022 = 2.2%). The samples with different incorporation amounts of V and Cu were prepared by varying the ratio of Mn to V and Cu. They were l %V-Cu-OMS-2 (i.e., approximately mol V / mol Mn = 1% and mol Cu / mol Mn = 1%), 5%V-Cu-OMS-2 (i.e., approximately mol V / mol Mn = 5% and mol Cu / mol Mn = 5%) and 10%V-Cu-OMS-2 (i.e., approximately mol V / mol Mn = 10% and mol Cu / mol Mn = 10%). Figure 3 shows the XRD patterns of OMS-2 materials. All of the diffraction peaks from the samples corresponded to those of OMS-2 materials. No impurity peaks were observed. However, an increase of V and Cu loadings resulted in a decrease in peak intensities and line broadening. This indicated a smaller crystal size and weaker crystallinity of the doped material. Figure 4 shows the FE-SEM images of the as-obtained OMS-2 materials, composed of fiber-like morphologies with different aspect ratios. As shown in Fig. 4a, b, OMS-2 has long fibers with a length of about several microns and a diameter of 20 nm. When 1% of V and Cu were incorporated into the OMS-2 material, the length of the fibers decreased dramatically to 300 — 500 nm. Meanwhile, the diameters of the fibers were 10— 20 nm. When the loading amount of V and Cu was increased to 2%, the morphologies of the sample did not exhibit a large effect compared with l%V-Cu-OMS-2. However, 5%V-Cu-OMS-2 shows rod-like morphology with a length of 100 - 200 nm and a diameter of 10 nm. 10%V-Cu-OMS-2 exhibits a similar rod-like morphology, but is less than 100 nm in length.

EXAMPLE 3

[0082] Hydrothermal synthesis. Nanostructure LiMnO _x may be prepared by an analogous method. Lithium permanganate (LiMn0 ₄ ) dissolved in water at pH= 7.0 and heated in a sealed vessel to 180°C for two days, and heated to 240°C produced nanostructured LiMnO _x having an OMS-2 structure. X-ray diffraction patterns of the materials are shown in Fig. 11. SEM images are shown in Figs. 12A and 12B.

EXAMPLE 4

[0083] DC resistivity measurements. The as-synthesized OMS-2 materials were finely ground and then about 0.3 g of the sample was pressed into a 1 mm thick pellet with a 13 mm diameter. The pellet was formed using an applied pressure of 10000 pounds for 2 min. To avoid movement of the pellets during the measurement, they were attached to a glass slide using a non- conductive epoxy resin. Conductive silver paste was used to attach silver wires to the pellet. Figure 5 showed the configuration of the tested sample on the glass slide. The DC electrical resistivity of the as-synthesized OMS materials was determined at room temperature by the four- probe or the van der Pauw method. The resistivity change of the OMS-2 materials as the function of different loading amounts is exhibited in Figure 6. The listed resistivities here are the average of three measurements. OMS-2 showed the lowest value of resistivity of all the samples, 49 Ω*αη, which is consistent with the resistivity of OMS-2 material prepared by a reflux method. The resistivities of the incorporated OMS-2 materials increased with an increase of the loading amounts of V and Cu. 10%V-Cu-OMS-2 showed the highest resistivity, which is 287 Q*cm. The trend indicated that the incorporation of V and Cu weakened the electrical conductivity of the OMS-2 materials.

EXAMPLE 5

[0084] Linear Scanning Voltammagram-Rotating Disk Electrode (LSV-RDE). The oxygen reduction reaction (ORR) activity of Ag-OMS-2 was measured by linear scanning voltammagram-rotating disk electrode, and compared with Na-OMS-5. To investigate oxygen reduction in aqueous electrolytes, rotating disk voltammetry (RDV) (Pine Instruments) was performed at 2500 rpm and a scan rate of 5 mV*s ^" ' . Rotating disk voltammetry (RDV) was used to elucidate the differences in the ability of the OMS materials to reduce oxygen in an aqueous environment. The Tafel equation was employed to investigate the linear relationship between the rate of the electrochemical reaction and the overpotential. The Tafel slopes were calculated at high overpotentials. To help further distinguish each material, the exchange current densities, which are measures of kinetics, were extrapolated from the Tafel plots. Results are shown in Fig. 13.

EXAMPLE 6

[0085] Lithium-air battery application. The Li-0 ₂ cell was made from a pure lithium metal foil as the anode and an oxygen cathode with multilayer structures laminated with a microporous PTFE layer to the side exposed to the gaseous environment. Ni mesh was used as a current collector. The electrolyte consisted of a solution of 1 M LiPF ₆ (lithium hexafluorophosphate) in 1 : 1 : 1 volume EC/DEC/DMC (where EC is ethylene carbonate, DEC is diethyl carbonate, and DMC is dimethyl carbonate). The cells were tested under dry 0 ₂ (g) at 1 atm and at 25 °C. The test profile consisted of an initial 2 h monitored rest, followed by a discharge at a current density of 0.15 mA/cm ² to a voltage cutoff of 1.5 V as shown in Fig. 7. The battery cell reached an average capacity of 2741 mAh/g of carbon, as is indicated in Table 1, which shows the specific capacity for these Li-0 ₂ batteries of Ag-OMS-2.

[0086] Na-OMS-5 was also tested, with discharge profile shown in Fig. 18 and Table 2.

The preparation of Na-OMS-5 can be found in Shen, X.; Ding, Y. S.; Liu, J.; Cai, J.; Laubernds,

K.; Zerger, R. P.; Vasiliev, A.; Aindow, M.; Suib, S. L. Control of Nano-scale Tunnel Sizes of

Porous Manganese Oxide Octahedral Molecular Sieve (OMS) Nanomaterials, Adv. Mater., 2005, 17, 805-809, which is hereby incorporated herein by reference in its entirety. Discharge profiles show the potential versus time and are a measure of the rate of loss of capacity in one cycle of the material.

[0087] Discharge profile for Ag-OMS-2 is shown in Fig. 19 and Table 3. Discharge profiles show the potential versus time and are a measure of the rate of loss of capacity in one cycle of the material.

EXAMPLE 7

[0088] Lithium-ion battery application. The electrochemical performance of the synthesized materials was evaluated in coin half-cells, shown in Fig. 14. Materials according to this invention may be incorporated into an electrode for the battery, for example, by a process shown in Fig. 15.

[0089] For example, cathode solids including 30 wt. % of KYNARFLEX® 2801 binder

(Atofina Chemicals, Inc.), 5 wt. % KS-15 graphite (Timcal), 5 wt. % Super P carbon (Comilog, S.A.) and 60 wt. % of active material (OMS-2), were dispersed in N-methyl-2-pyrrolidone solvent (Brand-Nu Laboratories, Inc.). The weight ratio of solids to solvent was 1 : 1. The resulting slurry was stirred and sonicated for 30 minutes and then spread onto the aluminum foil current collector using a Doctor-Blade technique. After solvent evaporation, coated foils were placed in a vacuum oven at 1 10 °C for 12 hours. The cathode coin half-cells, containing metallic lithium as the anode, were assembled under an argon atmosphere inside a glove box. The cells contained an electrolyte solution of 1.0 M LiPF ₆ dissolved in a 1/1/1 (vol.) EC/DMC/DEC mixture. The cells were discharged at room temperature with a 0.38 mA/cm ² current density in order to determine the cell voltage, capacity, and the discharge cycling efficiency of the cathode. The specific discharge capacities for all of the samples are listed in Fig. 8. Discharge curves for OMS-2 materials with different incorporation amounts are shown in Fig. 9. All of the samples showed similar S-shape discharge curves. Results showed that the as-synthesized V, Cu incorporated OMS materials (V-Cu-OMS-2) showed 40% enhancement of the discharge capacity from 124 mAh/g to 174 mAh/g with only 1 % incorporation of V and Cu into the OMS structure. With an increase of the loading amounts of V and Cu, the specific discharge capacities decreased. Fig. 10 shows the first discharge and charge cycle, and the reversibility of the capacity is 85.9%.

[0090] Performance of nanostructured LiMnO _x was also measured. Charge/discharge cycle is shown in Fig. 16A. The notation "C/5", "C/10", and "C/20" in this and subsequent Figures indicates the capacity (total charge) in Ah (amp*hours) to which the cell was charged prior to allowing discharge. That is "C/5" indicates that the cell was charged to 5 Ah, "C/10" indicates that the cell was charged to 10 Ah, and "C/20" indicates that the cell was charged to 20 Ah. Discharge capacity of nanostructured LiMnO _x over several cycles is shown in Figs. 16B and 17.

[0091] Zeolite-analogue manganese oxide octahedral molecular sieves (OMS) are porous metal oxide molecular sieves. These OMS materials are environmentally benign, low cost, and semiconducting. OMS materials can be used as electrode materials in lithium ion batteries and lithium air batteries for energy storage. For example, in lithium ion batteries, cryptomelane-type manganese oxide octahedral molecular sieve (OMS-2) materials with 2x2 tunnel form (Fig. 1) displayed high capacity (174 mAh/g) and lithium ion reversible properties. Such OMS-2 materials also showed high capacity (2741 mAh/g of carbon) in lithium air batteries. These unique materials exhibit high performances in lithium batteries.

[0092] Materials based on manganese (IV and III) oxide matrix possess versatile structures at angstrom scale and abundant structures at the nanometer scale, creating considerable pores for lithium intercalation in lithium ion batteries and for hosting oxygen reduction reactions and anchoring the reaction product U2O2 or L12O in lithium air batteries. Metal cations are often present in the tunnels of Mn0 ₂ materials to balance tunnel structures. Cryptomelane or hollandite structure performance in heterogeneous catalysis.

[0093] OMS-2 materials have abundant defects on the surface. The relatively loose Mn-0 bonds on the metal oxides surface may favor the association and dissociation of molecular oxygen on the electrocatalyst surfaces, which makes this family of materials attractive for both primary and secondary Li-O? batteries. On the other hand, the tunnel structure of manganese oxide allows lithium ions to be inserted and extracted. These unique properties make these OMS materials, especially OMS-2 materials, promising as excellent electrode materials in lithium batteries. It is also widely known that one-dimensional (ID) nanostructured electrode materials can favor electron transport in the batteries. Most synthetic OMS materials are ID in nanometer scale.

[0094] The currently most used electrode material in lithium ion batteries is LiCo0 ₂ , which is costly and toxic. Manganese oxides materials are only 3% of the cost of cobalt based oxides. The manganese oxides in an anode part of a lithium ion battery can be lithiated first and then delithiated, thus functioning as an intercalative material in a lithium ion battery. In this case, a lithium foil is used as a cathode. [0095] Oxygen reduction reactions (ORR) in lithium air batteries can be slow. The energy efficiency of lithium air batteries can be an issue, because the charge potentials that are used are higher than the cells' discharge potentials. Hence, good oxygen evolution reaction (OER) catalysts can be used. OER catalysts include Pt, Au, or Pd nanometer-scale particles. These noble metals are expensive and hard to make. Manganese oxides materials have the potential to be used as bi-functional electrocatalysts for ORR reactions in discharge processes and OER reactions in charge processes in rechargeable lithium batteries.

[0096] These nanostructured OMS materials are inexpensive and feasible to manufacture on an industrial scale, so that they can be used in lithium batteries for energy storage. Adding other carbon or silicon based materials, such as carbon black, graphite, graphene, carbon nanotubes, fullerene, and/or silicon nanomaterials into the OMS may result in the formation of advanced materials, such as OMS/C or OMS/Si composites. Such composites can be used as electrode materials for lithium batteries.

[0097] As described herein, all embodiments or subcombinations may be used in combination with all other embodiments or subcombinations, unless mutually exclusive.

[0098] The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.