Compositions and methods of making and use thereof

Abstract

Described herein are compositions and methods of making and use thereof. For example, disclosed herein are methods of making a composition, the method comprising sol-gel synthesis, the composition comprising Na(z)[Na(x)Ni(y)M(1-x-y)]O2, where 0.5 ≤ z ≤ 0.8; 0 ≤ x ≤ 1 / 3; 0 ≤ y ≤ 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced.

Description

[0001] COMPOSITIONS AND METHODS OF MAKING AND USE THEREOF

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 679,688 filed August 6, 2024, which is hereby incorporated herein by reference in its entirety.

[0004] STATEMENT OF GOVERNMENT SUPPORT

[0005] This invention was made with government support under Grant No. DE-SC0005397 awarded by the Department of Energy. The government has certain rights in the invention.

[0006] BACKGROUND

[0007] Secondary sodium batteries have yet to achieve the critical performance metrics required to serve as a viable alternative for certain applications. Layered NaxMOr oxides remain the prime candidate for enabling a commercial Na-ion battery that has a reasonable energy density and rate performance, but most investigated materials suffer from sodium ordering and layeredlayered phase transitions that induce numerous voltage plateaus in their electrochemical curve. The presence of numerous plateaus in the voltage curve for these materials upon sodium intercalation / deintercalation hinders their practicality. Compositions with improved properties for use in sodium ion batteries are needed. The compositions and methods discussed herein address these and other needs.

[0008] SUMMARY

[0009] In accordance with the purposes of the disclosed compositions and methods as embodied and broadly described herein, the disclosed subject matter relates to compositions and methods of making and use thereof.

[0010] For example, described herein are methods of making a composition, the methods comprising sol-gel synthesis, the composition comprising: where 0.5 < z < 0.8; 0 < x < 1 / 3; 0 < y < 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced.

[0011] In some examples, the composition has an empirical formula Na(Z)[Na(x)Ni(y)M(i-x-y)]O2.

[0012] In some examples, the composition comprises Na(3z)[Na(3x)Ni(3y)M(3-3x-3y)]O6.

[0013] In some examples, M is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Al, Sn, Sb, Te, or any combination thereof. In some examples, M is Te, Bi, Sb, or a combination thereof. In some examples, M is Te.

[0014] In some examples, the composition comprises a sodium excess layered oxide. In some examples, the composition comprises a P2 In some examples, sodium ions within the transition metal layer reversibly diffuse to the sodium layer during electrochemical cycling. In some examples, sodium ions occupy sites within the transition-metal layer of the layered oxide. In some examples, the sodium layer is disordered. In some examples, the method comprises a full sol-gel synthesis. In some examples, the method comprises: solvating a sodium containing precursor, a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent (e.g., citric acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel to form a ground mixture; and sintering the ground mixture to form the composition. In some examples, the sodium containing precursor is water-soluble. In some examples, the sodium containing precursor is water-soluble and comprises sodium acetate, sodium hydroxide, sodium oxalate, or a combination thereof. In some examples, the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble. In some examples, the method comprises a partial sol-gel synthesis. In some examples, the method comprises: solvating a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent (e.g., citric acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel in the presence of a sodium containing precursor, to form a ground mixture; and sintering the dried sol-gel to form the composition. In some examples, the sodium containing precursor comprises sodium carbonate. In some examples, the nickel containing precursor comprises an oxide, and the method further comprises contacting the nickel containing precursor with an acid (e.g., nitric acid) to digest the nickel containing precursor. In some examples, the nickel containing precursor is water-soluble. In some examples, the nickel containing precursor is water-soluble and comprises nickel nitrate. In some examples, the M containing precursor comprises an oxide, and the method further comprises contacting the M containing precursor with an acid (e.g., nitric acid) to digest the M containing precursor. In some examples, the M containing precursor is water-soluble. In some examples, the M containing precursor is water-soluble and comprises a nitrate, an acetate, a sulfate, a chloride, or a combination thereof. In some examples, the M containin comprises a nitrate. In some examples, the M containing precursor is water soluble, M is Te, and the M containing precursor is tellurium nitrate. In some examples, the nickel containing precursor and the M containing precursor are each water-soluble. In some examples, the chelating agent is present. In some examples, the chelating agent comprises citric acid. In some examples, the chelating agent is used to form the gel and ensure intermixing of all of the metal ions. In some examples, the solvent comprises water. In some examples, the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble and the solvent comprises water. In some examples, the method further comprises agitating (e.g., stirring) the solution. In some examples, sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 6-72 hours, and subsequently cooling to room temperature at a rate of from 0.5 to 20°C per minute. In some examples, sintering comprises heating the ground mixture at a temperature of from 800 to 850°C. In some examples, sintering comprises heating the ground mixture at the temperature for an amount of time of from 12-24 hours. In some examples, sintering comprises heating the ground mixture at the temperature for the amount of time, and subsequently cooling at a rate of from 1 to 5°C per minute. In some examples, sintering comprises heating the ground mixture at a temperature of from 800 to 850°C (e.g., 810°C) for an amount of time of from 12-24 hours, and subsequently cooling at a rate of from 1 to 5°C per minute (e.g., 2°C per minute) to room temperature. In some examples, the method results in a more homogenous particle composition, morphology and size distribution relative to traditional solid state methods. In some examples, an electrochemical cell comprising the composition exhibits a smooth voltage curve. In some examples, the composition exhibits a Na-ion conductivity of 10-5S / cm or more at 297 K. In some examples, the composition has a mitigated structural transition when cycled in an electrochemical cell, for example as compared to a composition without excess sodium. Also disclosed herein are compositions made by any of the methods described herein. Also disclosed herein are systems comprising any of the compositions made by any of the methods described herein. Also disclosed herein are articles or devices compr any of the methods described herein. In some examples, the article or device comprises an electrode, such as a cathode. In some examples, the article or device comprises an electrochemical cell, such as an electrochemical cell comprising the electrode. In some examples, the article or device comprises an energy storage device, such as a battery, for example an energy storage device comprising the electrode. In some examples, the article or device comprises a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising the electrode. In some examples, the article or device comprises a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechargeable battery comprising the electrode. In some examples, the composition has a mitigated structural transition when cycled, for example as compared to a composition without excess sodium. In some examples, the article or device exhibits extended cycle life, for example as compared to an article or device comprising a composition without excess sodium. Also disclosed herein are methods of use of any of the compositions made by any of the methods described herein. In some examples, the method comprises using the composition in an electrode, such as a cathode. In some examples, the method comprises using the composition in an electrochemical cell, such as an electrochemical cell using the electrode. In some examples, the method comprises using the composition in an energy storage device, such as battery, for example an energy storage device using the electrode. In some examples, the method comprises using the composition in a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising the electrode. In some examples, the method comprises using the composition in a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechargeable battery comprising the electrode. Also disclosed herein are batteries comprising any of the compositions made by any of the methods described herein. In some examples, the battery is a sodium ion battery and / or a rechargeable battery. Also disclosed herein are systems or articles comprising one or more of the batteries described herein. In some examples, the system or article comprises an electronic device, such as a portable electronic device, a laptop, a watch, or a cell phone. In some examples, the system or article comprises a short range electric vehicle, such as an e-bike or scooter. In some examples, the system or article comprises a large-scale energy storage system. Additional advantages of the disclosed composition in the description which follows, and in part will be obvious from the description. The advantages of the disclosed compositions and methods will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed compositions and methods, as claimed. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE FIGURES The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure, and together with the description, serve to explain the principles of the disclosure. Figure 1A-Figure 1B. Figure 1A) Powder X-ray diffraction patterns for pure phase Na2+xNi2-x / 2TeO6 (0 ≤ x ≤ 0.3) materials with a zoom in of the superstructure region of 19° to 34° 2θ shown in Figure 1B. Figure 2A-Figure 2B. Depiction of the crystal structures and local sodium environments for the P63 / mcm and P6322 P2-layered structures observed in the Na2+xNi2-x / 2TeO6(0 ≤ x ≤ 0.3) system. Figure 3.2-D23Na MAS NMR spectra of Na2Ni2TeO6collected with the pj-MATPASS pulse sequence collected at a spinning frequency of 8 kHz. Figure 4.1-D23Na MAS NMR spectra of Na2+xNi2-x / 2TeO6 (0 ≤ x ≤ 0.3) acquired at 30 kHz. The blue arrows for each spectra designate peaks associated with distinct sodium sites within their respective structures. Figure 5A-Figure 5B. Voltage versus composition curves for P2-layered Na2Ni2TeO6cycled in the voltage ranges of Figure 5A) 2.5 to 4.2 V and Figure 5B) 2.5 to 4.4 V versus Na+ / Na. The bottom x-axis shows the total sodium content in the material. The top x-axis shows the sodium content within the sodium layer during cycling in accordance with the classical NaxMO2layered formula. These cells were cycled against sodium metal with 1 M NaClO4PC: FEC (9:1) (v:v) as the electrolyte. Figure 6A-Figure 6F. Voltage versus composition curves for P2-layered Na2+xNi2-x / 2TeO6(0 ≤ x ≤ 0.3) cycled in the voltage range of Figure 6A, Figure 6C, Figure 6E) 2.5 to 4.2 V and Figure 6B, Figure 6D, Figure 6F) 2.5 to 4.4 V versus Na+ / Na. The bottom x-axis shows the total sodium content in the material. The top x-axis shows the so during cycling in accordance with the classical NayMO2layered formula. Additional sodium in the MO2 layer may contribute to the overall capacity, but is not considered in the calculation of the sodium layer Na content, y. These cells were cycled against sodium metal with 1 M NaClO4PC: FEC (9:1) (v:v) as the electrolyte. Figure 7A-Figure 7C. Figure 7A) DFT energetics of P63 / mcm and P6322 structures with Monte Carlo Na / VNa swapping step. Only the energies of ‘accepted’ structures are shown. At each MC step, the positions of all atoms were optimized under fixed cell conditions. Dashed lines indicate different temperature regions. After 100 MC steps at 2000 K and 1000 K, the lowest energy structure found was fully optimized and used for the subsequent temperature step. (Figure 7B) and (Figure 7C) optimized supercell structures of lowest energy P63 / mcm and P6322 structures, respectively, found at 300 K with MC. Relative energy difference between the structures is shown in meV per formula unit. The ordering of the Na1, Na2 and Na3’ (P6322) sites in the two Na layers (ab plane) of both structures is shown. Figure 8A-Figure 8C. Figure 8A) DFT energetics of Na substituted P63 / mcm and P6322 structures with Monte Carlo Na / VNa swapping step. Only the energies of ‘accepted’ structures are shown. At each MC step, the positions of all atoms were optimized under fixed cell conditions. The dashed line indicates the different temperature regions. After 100 MC steps at 1000 K, the lowest energy structure found was fully optimized and used for the subsequent temperature step. (Figure 8B) and (Figure 8C) optimized supercell structures of lowest energy P63 / mcm and P6322 structures, respectively, found at 300 K with MC. Relative energy difference between the structures is shown in meV per formula unit. The ordering of the Na1, Na2 and Na3’ (P6322) sites in the two Na layers (ab plane) and Na4 site in the Ni-Te layer of both structures is shown. Figure 9A-Figure 9B. (Figure 9A)23Na MAS NMR spectra of Na2+xNi2-x / 2TeO6 phases from x = 0 - 0.3. All spectra were acquired at a spinning speed of 30 kHz. Circles and stars indicate the isotropic peaks in the P63 / mcm to the P6322 structures, respectively. Dashed lines are included to show the evolution of the isotropic peaks between spectra. All spectra are scaled to a maximum peak intensity of unity. (Figure 9B) Zoomed in23Na NMR spectrum of the Na2.3Ni1.85TeO6phase, showing the isotropic peaks at negative frequencies. The shifts of the isotropic resonances (in ppm) are given above the peaks. Spinning sidebands are indicated with symbols (*, +, #). Figure 10. Comparison of experimental (Exp.) and the P63 / mcm and P6322 structures of unsubstituted Na2Ni2TeO6. All computed shifts are scaled to 320 K using a spin of S=1 and a Weiss constant of θ= -32 K. Figure 11A-Figure 11B. (Figure 11A) Comparison of23Na NMR shifts of compound Na2.3Ni1.85TeO6 (Exp.) with DFT computed shifts for lower energy Na-substituted P63 / mcm and P6322 supercell structures (Na20Ni14Te8O48). (Figure 11B) Comparison of experimental vs computationally predicted NMR spectra for P63 / mcm and P6322 structure. A dynamic average of the shifts in the Na-layer was taken for computational spectra. The computational peaks are represented by a Gaussian with a width of 50 ppm. The isotropic resonances are indicated about the peaks in ppm. Isotropic peaks in the experimental spectrum are indicated with stars. DETAILED DESCRIPTION The compositions and methods described herein may be understood more readily by reference to the following detailed description of specific aspects of the disclosed subject matter and the Examples included therein. Before the present compositions and methods are disclosed and described, it is to be understood that the aspects described below are not limited to specific synthetic methods or specific reagents, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Also, throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon. General Definitions In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings. Throughout the description and claims of this specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps. As used in the specification and in the claims, the term “comprising” can include the aspects “consisting of” and “consisting essentially of.” As used in the description and the appended claims “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions, reference to “an agent” includes mixtures of two or more such agents, reference to “the component” includes mixtures of two or more such components, and the like. “Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. By “about” is meant within 5% of the value, e.g., within 4, 3, 2, or 1% of the value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, a description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6 and any whole and partial increments therebetween. This applies regardless of the breadth of the range. When the specific values are disclosed between two end values, it is understood that these end values can also be included. For the terms “for example” and “such as,” and grammatical equivalences thereof, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. It is further understood that these phrases are not used in a restrictive sense, but for explanatory purposes. “Exemplary” means “an example of” and is not intended to convey an indication of a preferred or ideal embodiment. It is understood that throughout this specification the identifiers “first” and “second” are used solely to aid in distinguishing the various components and steps of the disclosed subject matter. The identifiers “first” and “second” are not intende amount, preference, or importance to the components or steps modified by these terms. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the term "substantially" means that the subsequently described event or circumstance completely occurs or that the subsequently described event or circumstance generally, typically, or approximately occurs. Still further, the term “substantially” can, in some aspects, refer to at least about 80 %, at least about 85 %, at least about 90 %, at least about 91 %, at least about 92 %, at least about 93 %, at least about 94 %, at least about 95 %, at least about 96 %, at least about 97 %, at least about 98 %, at least about 99 %, or about 100 % of the stated property, component, composition, or other condition for which substantially is used to characterize or otherwise quantify an amount. In other aspects, as used herein, the term “substantially free,” when used in the context of a composition or component of a composition that is substantially absent, is intended to refer to an amount that is then about 1 % by weight, e.g., less than about 0.5 % by weight, less than about 0.1 % by weight, less than about 0.05 % by weight, or less than about 0.01 % by weight of the stated material, based on the total weight of the composition. The expressions “ambient temperature” and “room temperature” as used herein are understood in the art and refer generally to a temperature from about 20°C to about 35°C. References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a mixture containing 2 parts by weight of component X and 5 parts by weight of component Y, components X and Y are present at a weight ratio of 2:5 and are present in such a ratio regardless of whether additional components are contained in the mixture. A weight percent (wt.%) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included. A volume percent (vol%) of a component, unless specifically stated to the contrary, is based on the total volume of the formulation or composition in which the component is included. It is understood that the term “salt,” as used herein, refers to a chemical compound that can be formed form a reaction between an acid and a base. It is understood that the term “salt,” as used herein, encompasses both inorganic and organic salts capable of providing the desired properties to the composition. In still further aspects, a cati metal cation. While aspects of the present invention can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of ordinary skill in the art will understand that each aspect of the present invention can be described and claimed in any statutory class. Unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that an order be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to the arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. “Phase,” as used herein, generally refers to a region of a material having a substantially uniform composition which is a distinct and physically separate portion of a heterogeneous system. The term “phase” does not imply that the material making up a phase is a chemically pure substance, but merely that the chemical and / or physical properties of the material making up the phase are essentially uniform throughout the material, and that these chemical and / or physical properties differ significantly from the chemical and / or physical properties of another phase within the material. Examples of physical properties include density, thickness, aspect ratio, specific surface area, porosity, and dimensionality. Examples of chemical properties include chemical composition. As used herein, “molecular weight” refers to number average molecular weight as measured by1H NMR spectroscopy, unless indicated otherwise. The organic moieties mentioned when defining variable positions within the general formulae described herein (e.g., the term “halogen”) are collective terms for the individual substituents encompassed by the organic moiety. The prefix Cn-Cmpreceding a group or moiety indicates, in each case, the possible number of carbon atoms in the group or moiety that follows. The term “ion,” as used herein, refers to any molecule, portion of a molecule, cluster of molecules, molecular complex, moiety, or atom that contains a charge (positive, negative, or both at the same time within one molecule, cluster of molecules, molecular complex, or moiety (e.g., zwitterions)) or that can be made to contain a charge. molecule, portion of a molecule, cluster of molecules, molecular complex, moiety, or atom are disclosed herein and can be accomplished by methods known in the art, e.g., protonation, deprotonation, oxidation, reduction, alkylation, acetylation, esterification, de-esterification, hydrolysis, etc. The term “anion” is a type of ion and is included within the meaning of the term “ion.” An “anion” is any molecule, portion of a molecule (e.g., zwitterion), cluster of molecules, molecular complex, moiety, or atom that contains a net negative charge or that can be made to contain a net negative charge. The term “anion precursor” is used herein to specifically refer to a molecule that can be converted to an anion via a chemical reaction (e.g., deprotonation). The term “cation” is a type of ion and is included within the meaning of the term “ion.” A “cation” is any molecule, portion of a molecule (e.g., zwitterion), cluster of molecules, molecular complex, moiety, or atom, that contains a net positive charge or that can be made to contain a net positive charge. The term “cation precursor” is used herein to specifically refer to a molecule that can be converted to a cation via a chemical reaction (e.g., protonation or alkylation). Compositions and Methods of Making Disclosed herein are compositions and methods of making and use thereof. For example, disclosed herein are methods of making a composition, the method comprising sol-gel synthesis, the composition comprising: Na(z)[Na(x)Ni(y)M(1-x-y)]O2 where 0.5 ≤ z ≤ 0.8; 0 ≤ x ≤ 1 / 3; 0 ≤ y ≤ 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced. In some examples, z is 0.5 or more (e.g., 0.55 or more, 0.6 or more, 0.65 or more, 0.7 or more, or 0.75 or more). In some examples, z is 0.8 or less (e.g., 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, or 0.55 or less). The value for z can range from any of the minimum values described above to any of the maximum values described above. For example, z can be from 0.5 to 0.8 (e.g., from 0.5 to 0.65, from 0.65 to 0.8, from 0.5 to 0.6, from 0.6 to 0.7, from 0.7 to 0.8, from 0.5 to 0.7, from 0.6 to 0.8, or from 0.55 to 0.75). In some examples, x is 0 or more (e.g., 0.05 or mor more, 0.25 or more, or 0.3 or more). In some examples, x is 1 / 3 or less (e.g., 0.3 or less, 0.25 or less, 0.2 or less, 0.15 or less, 0.1 or less, or 0.05 or less). The value for x can range from any of the minimum values described above to any of the maximum values described above. For example, x can be from 0 to 1 / 3 (e.g., from 0 to 0.15, from 0.15 to 1 / 3, from 0 to 0.1, from 0.1 to 0.2, from 0.2 to 1 / 3, from 0.05 to 1 / 3, from 0.1 to 1 / 3, from 0 to 0.3, from 0 to 0.2, from 0.05 to 0.3, or from 0.1 to 0.25). In some examples, y is 0 or more (e.g., 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more, 0.45 or more, 0.5 or more, 0.55 or more, 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, 0.8 or more, 0.85 or more, or 0.9 or more). In some examples, y is 1 or less (e.g., 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, 0.55 or less, 0.5 or less, 0.45 or less, 0.4 or less, 0.35 or less, 0.3 or less, 0.25 or less, 0.2 or less, 0.15 or less, or 0.1 or less). The value of y can range from any of the minimum values described above to any of the maximum values described above. For example, y can be from 0 to 1 (e.g., from 0 to 0.5, from 0.5 to 1, from 0 to 0.2, from 0.2 to 0.4, from 0.4 to 0.6, from 0.6 to 0.8, from 0.8 to 1, from 0.1 to 1, from 0.2 to 1, from 0.4 to 1, from 0.6 to 1, from 0 to 0.9, from 0 to 0.8, from 0 to 0.6, from 0 to 0.4, from 0.1 to 0.9, or from 0.2 to 0.8). In some examples, the composition has an empirical formula Na(z)[Na(x)Ni(y)M(1-x-y)]O2. In some examples, the composition comprises Na(3z)[Na(3x)Ni(3y)M(3-3x-3y)]O6. Examples of 3d transition metals include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn. Examples of 4d transition metals include Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, and Cd. In some examples, M is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Al, Sn, Sb, Te, or a combination thereof. In some examples, M is Te, Bi, Sb, or a combination thereof. In some examples, M is Te. In some examples, the composition comprises a sodium excess layered oxide. In some examples, the composition comprises a P2 layered system. In some examples, sodium ions within the transition metal-layer reversibly diffuse to the sodium layer during electrochemical cycling. In some examples, sodium ions occupy sites within the transition-metal layer of the layered oxide. In some examples, the sodium layer is disordered. In some examples, the method comprises a full sol-gel synthesis (e.g., the method consists essentially of or consists of a sol-gel synthesis). For example, the method can comprise: solvating a sodium containing precursor, a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the pres acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel to form a ground mixture; and sintering the ground mixture to form the composition. In some examples, the sodium containing precursor is water-soluble. Examples of water- soluble sodium compounds include, but are not limited to, sodium halides, sodium sulfates, sodium nitrates, sodium carboxylates, and sodium hydroxides. In some examples, the sodium containing precursor is water-soluble and comprises sodium acetate, sodium hydroxide, sodium oxalate, or a combination thereof. In some examples, the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble. In some examples, the method comprises a partial sol-gel synthesis. For example, the method can comprise: solvating a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent (e.g., citric acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried-sol gel in the presence of a sodium containing precursor, to form a ground mixture; and sintering the dried sol-gel to form the composition. In some examples, the sodium containing precursor comprises sodium carbonate. In some examples, the nickel containing precursor comprises an oxide, and the method further comprises contacting the nickel containing precursor with an acid (e.g., nitric acid) to digest the nickel containing precursor. In some examples, the nickel containing precursor is water-soluble. Examples of water soluble nickel compounds include, but are not limited to, nickel acetate, nickel bromide, nickel chloride, nickel iodide, nickel nitrate, and nickel sulfate. In some examples, the nickel containing precursor is water-soluble and comprises nickel nitrate. In some examples, the M containing precursor comprises an oxide, and the method further comprises contacting the M containing precursor with an acid (e.g., nitric acid) to digest the M containing precursor. In some examples, the M containing precursor is water-soluble. In some examples, the M containing precursor is water-soluble and comprises a nitrate, an acetate, a sulfate, a chloride, or a combination thereof. In some examples, the M containing precursor is water-soluble and comprises a nitrate. In some examples, the M containing precursor is water-soluble, M is Te, and the M containing precursor is tellurium nitrate. In some examples, the nickel containing precursor each water-soluble. In some examples, the chelating agent is present. In some examples, the chelating agent comprises citric acid. In some examples, the chelating agent is used to form the gel and ensure intermixing of all of the metal ions. The solvent can comprise any suitable solvent. The solvent can, for example, comprise ethylene glycol, polyethylene glycol, glycerol, alkane diol, ethanol, methanol, propanol, isopropanol, water, acetonitrile, acetone, tetraglyme, propylene carbonate, diglyme, dimethyl sulfoxide (DMSO), dimethoxyethane, dimethylacetamide, hexafluoro-2-propanol, or combinations thereof. In some examples, the solvent comprises water. In some examples, the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble and the solvent comprises water. In some examples, the method further comprises agitating (e.g., stirring) the solution. In some examples, sintering comprises heating the ground mixture at a temperature for an amount of time, and subsequently cooling to room temperature at a rate. In some examples, sintering comprises heating the ground mixture at a temperature of 700°C or more (e.g., 725°C or more, 750°C or more, 775°C or more, 800°C or more, 825°C or more, 850°C or more, 875°C or more, 900°C or more, 925°C or more, 950°C or more, 975°C or more, 1000°C or more, 1025°C or more, 1050°C or more, 1075°C or more, 1100°C or more, 1125°C or more, or 1150°C or more). In some examples, sintering comprises heating the ground mixture at a temperature of 1200°C or less (e.g., 1175°C or less, 1150°C or less, 1125°C or less, 1100°C or less, 1075°C or less, 1050°C or less, 1025°C or less, 1000°C or less, 975°C or less, 950°C or less, 925°C or less, 900°C or less, 875°C or less, 850°C or less, 825°C or less, 800°C or less, 775°C or less, or 750°C or less). The temperature can range from any of the minimum values described above to any of the maximum values described above. For example, sintering can comprise heating the ground mixture at a temperature of from 700 to 1200°C (e.g., from 700 to 950°C, from 950 to 1200°C, from 700 to 800°C, from 800 to 900°C, from 900 to 1000°C, from 1000 to 1100°C, from 1100 to 1200°C, from 700 to 1000°C, from 700 to 900°C, from 800 to 1200°C, from 725 to 1000°C, from 750 to 900°C, or from 800 to 850°C). In some examples, sintering can comprise heating the ground mixture at a temperature of from 800 to 850°C. In some examples, sintering comprises heating the ground mixture at a temperature for an amount of time of 6 hours or more (e.g., 8 hours or more, 10 hours or more, 12 hours or more, 14 hours or more, 16 hours or more, 18 hours or more, 20 hours or more, 22 hours or more, 24 hours or more, 30 hours or more, 36 hours or more, 42 hours or more, 48 hours or more, 54 hours or more, 60 hours or more, or 66 hours or more). In heating the ground mixture at a temperature for an amount of time of 72 hours or less (e.g., 66 hours or less, 60 hours or less, 54 hours or less, 48 hours or less, 42 hours or less, 36 hours or less, 30 hours or less, 24 hours or less, 22 hours or less, 20 hours or less, 18 hours or less, 16 hours or less, 14 hours or less, 12 hours or less, 10 hours or less, or 8 hours or less). The amount of time can range from any of the minimum values described above to any of the maximum values described above. For example, sintering can comprise heating the ground mixture at a temperature for an amount of time of from 6 to 72 hours (e.g., from 6 to 36 hours, from 36 to 72 hours, from 6 to 24 hours, from 24 to 48 hours, from 48 to 72 hours, from 6 to 60 hours, from 6 to 48 hours, from 6 to 36 hours, or from 12 to 24 hours). In some examples, sintering can comprise heating the ground mixture at a temperature for an amount of time of from 12 to 24 hours. In some examples, sintering comprises heating the ground mixture at a temperature for an amount of time, and subsequently cooling to room temperature at a rate of 0.5°C per minute or more (e.g., 0.75°C per minute or more, 1°C per minute or more, 1.25°C per minute or more, 1.5°C per minute or more, 1.75°C per minute or more, 2°C per minute or more, 2.25°C per minute or more, 2.5°C per minute or more, 2.75°C per minute or more, 3°C per minute or more, 3.25°C per minute or more, 3.5°C per minute or more, 3.75°C per minute or more, 4°C per minute or more, 4.25°C per minute or more, 4.5°C per minute or more, 4.75°C per minute or more, 5°C per minute or more, 5.5 °C per minute or more, 6°C per minute or more, 6.5°C per minute or more, 7°C per minute or more, 7.5°C per minute or more, 8°C per minute or more, 8.5°C per minute or more, 9°C per minute or more, 9.5°C per minute or more, 10°C per minute or more, 11°C per minute or more, 12°C per minute or more, 13°C per minute or more, 14°C per minute or more, 15°C per minute or more, 16°C per minute or more, 17°C per minute or more, or 18°C per minute or more). In some examples, sintering comprises heating the ground mixture at a temperature for an amount of time, and subsequently cooling to room temperature at a rate of 20°C per minute or less (e.g., 19°C per minute or less, 18°C per minute or less, 17°C per minute or less, 16°C per minute or less, 15°C per minute or less, 14°C per minute or less, 13°C per minute or less, 12°C per minute or less, 11°C per minute or less, 10°C per minute or less, 9.5°C per minute or less, 9°C per minute or less, 8.5°C per minute or less, 8°C per minute or less, 7.5°C per minute or less, 7°C per minute or less, 6.5°C per minute or less, 6°C per minute or less, 5.5°C per minute or less, 5°C per minute or less, 4.75°C per minute or less, 4.5 °C per minute or less, 4.25°C per minute or less, 4°C per minute or less, 3.75°C per minute or less, 3.5°C per minute or less, 3.25°C per minute or less, 3°C per minute or less, 2.75°C per minute or less, 2.5°C per minute or less, 2.25°C per minute or less, 2 minute or less, 1.5°C per minute or less, 1.25°C per minute or less, 1 C per minute or less, or 0.75°C per minute or less). The rate of cooling to room temperature can range from any of the minimum values described above to any of the maximum values described above. For example, sintering can comprise heating the ground mixture at a temperature for an amount of time, and subsequently cooling to room temperature at a rate of from 0.5 to 20°C per minute (e.g., from 0.5 to 10°C per minute, from 10 to 20°C per minute, from 0.5 to 4°C per minute, from 4 to 8°C per minute, from 8 to 12°C per minute, from 12 to 16°C per minute, from 16 to 20°C per minute, from 0.5 to 15°C per minute, from 0.5 to 10°C per minute, or from 1 to 5°C per minute). In some examples, sintering can comprise heating the ground mixture at a temperature for an amount of time, and subsequently cooling to room temperature at a rate of from 1 to 5°C per minute. In some examples, sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 6-72 hours, and subsequently cooling at a rate of from 0.5 to 20°C per minute to room temperature. In some examples, sintering comprises heating the ground mixture at a temperature of 800 to 850°C for an amount of time of from 6-72 hours, and subsequently cooling at a rate of from 0.5 to 20°C per minute to room temperature. In some examples, sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 12-24 hours, and subsequently cooling at a rate of from 0.5 to 20°C per minute to room temperature. In some examples, sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 6-72 hours, and subsequently cooling too room temperature at a rate of from 1 to 5°C per minute. In some examples, sintering comprises heating the ground mixture at a temperature of 800 to 850°C for an amount of time of from 12-24 hours, and subsequently cooling at a rate of from 0.5 to 20°C per minute to room temperature. In some examples, sintering comprises heating the ground mixture at a temperature of 800 to 850°C for an amount of time of from 6-72 hours, and subsequently cooling too room temperature at a rate of from 1 to 5°C per minute. In some examples, sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 12-24 hours, and subsequently cooling to room temperature at a rate of from 1 to 5°C per minute. In some examples, sintering comprises heating the from 800 to 850°C (e.g., 810°C) for an amount of time of from 1224 hours, and subsequently cooling at a rate of from 1 to 5°C per minute (e.g., 2°C per minute) to room temperature. In some examples, the method results in a more homogenous particle composition, morphology and size distribution relative to traditional solid state methods. In some examples, an electrochemical cell comprising the composition exhibits a smooth voltage curve. In some examples, the composition exhibits a Na-ion conductivity of 1 × 10-5S / cm or more at 297 K (e.g., 5 × 10-5S / cm or more, 1 × 10-4S / cm or more, 5 × 10-4S / cm or more, 1 × 10-3S / cm or more, or 5 × 10-3S / cm or more). In some examples, the composition exhibits a Na- ion conductivity of 1 × 10-2S / cm or less at 297 K (e.g., 5 × 10-3S / cm or less, 1 × 10-3S / cm or less, 5 × 10-4S / cm or less, 1 × 10-4S / cm or less, or 5 × 10-5S / cm or less). The Na-ion conductivity of the composition at 397 K can range from any of the minimum values described above to any of the maximum values described above. For example, the composition can exhibit a Na-ion conductivity of from 1 × 10-5to 1 × 10-2S / cm at 297 K (e.g., from 1 × 10-5to 5 × 10-4S / cm, from 5 × 10-4to 1 × 10-2S / cm, from 1 × 10-5to 1 × 10-4S / cm, from 1 × 10-4to 1 × 10-3, from 1 × 10-3to 1 × 10-2S / cm, from 1 × 10-4to 1 × 10-2S / cm, or from 5 × 10-4to 1 × 10-2S / cm). In some examples, the composition has a mitigated structural transition when cycled in an electrochemical cell, for example as compared to a composition without excess sodium. Also disclosed herein are any of the compositions made by any of the methods disclosed herein. Systems, Devices, Articles, and Methods of Use Also disclosed herein are systems comprising any of the compositions made by any of the methods disclosed herein. Also disclosed herein are articles and / or devices comprising any of the compositions made by any of the methods disclosed herein. In some examples, the article or device comprises an electrode, such as a cathode. In some examples, the article or device comprises an electrochemical cell, such as an electrochemical cell comprising an electrode comprising the composition. In some examples, the article or device comprises an energy storage device, such as a battery, for example an energy storage device comprising an electrode comprising the composition. In some examples, the article or device comprises a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising an electrode comprising the composition. In some examples, the article or device comprises a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechar electrode comprising the composition. In some examples, the composition has a mitigated structural transition when cycled, for example as compared to a composition without excess sodium. In some examples, the article or device exhibits extended cycle life, for example as compared to an article or device comprising a composition without excess sodium. Also disclosed herein are methods of use of any of the compositions made by any of the methods described herein. For example, the method can comprise using the composition in an electrode, such as a cathode. In some examples, the method comprises using the composition in an electrochemical cell, such as an electrochemical cell using the electrode using the composition. In some examples, the method comprises using the composition in an energy storage device, such as battery, for example an energy storage device using the electrode using the composition. In some examples, the method comprises using the composition in a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising the electrode using the composition. In some examples, the method comprises using the composition in a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechargeable battery comprising the electrode using the composition. Also disclosed herein are batteries comprising any of the compositions made by any of the methods described herein. In some examples, the battery is a sodium ion battery and / or a rechargeable battery. Also disclosed herein are systems and / or articles comprising one or more of the batteries described herein. For example, the system and / or article can comprise an electronic device, such as a portable electronic device, a laptop, a watch, or a cell phone. In some examples, the system and / or article can comprise a short range electric vehicle, such as an e-bike or scooter. In some examples, the system and / or article can comprise a large-scale energy storage system. A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. The examples below are intended to further illustrate certain aspects of the systems and methods described herein, and are not intended to limit the scope of the claims. EXAMPLES The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to results. These examples are not intended to exclude equivalents and variations of the present invention which are apparent to one skilled in the art. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. There are numerous variations and combinations of measurement conditions, e.g., component concentrations, temperatures, pressures and other measurement ranges and conditions that can be used to optimize the described process. Example 1 Described herein are compositions and methods of making and use thereof. For example, described herein are methods of making compositions comprising: Na(z)[Na(x)Ni(y)M(1-x-y)]O2where 0.5 ≤ z ≤ 0.8; 0 ≤ x ≤ 1; 0 ≤ y ≤ 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced. 3d transition metals include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn. 4d transition metals include Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, and Cd. Any composition having the above empirical formula are disclosed herein. For example, also disclosed herein are compositions comprising Na(3z)[Na(3x)Ni(3y)M(3-3x-3y)]O6. In some examples, the compositions comprise a P2 layered system. The methods can, for example, comprise sol-gel synthesis, such as a full sol-gel synthesis or a partial sol-gel synthesis. Full sol-gel synthesis: The methods can use a water-soluble sodium starting material, such as sodium acetate or sodium hydroxide. The remaining components (e.g., nickel and M, such as tellurium) can either be used in their oxide form if an acid is used (e.g., nitric acid) to digest them, or a water-soluble form (such as Nickel Nitrate and Tellurium Nitrate) can be used. Additionally, a chelating agent, such as citric acid, is used to form the gel and ensure intermixing of all of the metal-ions. Each constituent precursor is solvated and stirred in been dissolved, the solution can then be heated to evaporate the water and form a gel . This gel is then taken to slightly higher elevated temperature to “burn off” or remove and residual nitrates and other compounds not critical to the final synthesis. The final dried sol-gel is then ground and heated to a final sintering temperature, in this case 810°C for 12-24 hours and slow cooled at 2°C per minute to room-temperature. This method results in a more homogenous particle composition, morphology and size distribution relative to traditional solid state methods. Partial sol-gel synthesis (e.g., Sol-gel and solid-state synthesis): This method is similar to the above method with the exception that the sodium starting material does not need to be added to the solution when forming the sol-gel. Therefore, a Nickel-Tellurium sol-gel can be formed and ground, whereupon the sodium precursor, such as sodium carbonate can be ground or ball- milled with the sol-gel to provide a sodium source for the final sintering step. Similar to above, the final sintering step can be 810°C for 12-24 hours and slow cooled at 2°C per minute to room- temperature. This route may be preferred to limit water usage as sodium carbonate has a lower solubility in water that sodium hydroxide. Also, sodium carbonate is less expensive and far safer to handle than sodium hydroxide. Also described herein are compositions made by any of the methods described herein. In some examples, a wet chemical method can produce lower particle size distribution and a more uniform morphology than a traditional solid-state method. The electrochemical performance of a cell comprising the compositions can be an indication of this. Example 2 - Sodium excess layered oxide cathodes for rechargeable batteries Described herein is an unconventional doping strategy for compositional control of sodium cathode materials. Specifically, in layered sodium-ion cathode materials, it is largely thought that sodium-ions cannot occupy sites within the transition-metal layer. The compositions described herein have disproven this convention, as confirmed by extensive material characterization. Additionally, the incorporation of sodium within the transition-metal layer of the material has been shown to drastically improve electrochemical performance of the cathode materials by causing disorder in the adjacent sodium layer. Sodium layered oxide cathodes typically show a series of curves in their electrochemical voltage profile that are induced by gliding of the transition metal layers as well as ordering of the sodium ions within the sodium layer. By doping even a small amount of sodium into the transition metal layer, it has been shown that superior electrochemical performance can be obtained with a smooth voltage curve that is reminiscent of commercial lithium transition-metal is Na doped P2-layered Na2Ni2TeO6system with sodium swapped for nickel in the form of Na2+xNi2-x / 2TeO6. This material doping strategy can be applied to any sodium transition-metal layered oxide material. This strategy incorporates sodium doping for a transition-metal ion in a layered oxide, which was previously thought to be impossible within the layered oxide structural motif for rechargeable sodium-ion battery cathode materials. This doping strategy improves electrochemical performance by removing the “electrochemical devil’s staircase” and allowing the sodium layered oxide cathode material to have a smooth voltage curve that is similar to the lithium layered oxides that have been commercialized in lithium-ion batteries. Additionally, the smooth voltage curve is easier to design a commercial secondary battery around from a battery management system perspective. The excess Na in the structure also provides an additional source of electrode capacity, unlike in conventional doping strategies using inert cation species. Uses include, but are not limited to, rechargeable sodium-ion batteries. Example 3 - Enhanced Electrochemical Performance of P2-Na2+xNi2-(x / 2)TeO6 (0 ≤ x ≤ 0.5) through Sodium Substitution in the Transition-Metal Layer Although secondary lithium batteries have emerged as the near-term solution for electrification of mobility and transitioning society towards a sustainable existence, there remain applications where secondary lithium batteries are not the most attractive energy storage solution. Secondary sodium batteries maintain an attractive value proposition for large-scale grid applications and portable electronics that prioritize low-cost over energy and power density. However, secondary sodium batteries have yet to achieve the critical performance metrics required to serve as a viable alternative for these applications. Layered NaxMO2 oxides remain the prime candidate for enabling a commercial Na-ion battery that has a reasonable energy density and rate performance, but most investigated materials suffer from sodium ordering and layered-layered phase transitions that induce numerous voltage plateaus in their electrochemical curve. The presence of numerous plateaus in the voltage curve for these materials upon sodium intercalation / deintercalation hinders their practicality. Layered NaxMO2oxides that present honeycomb ordering within the MO2layer have developed increasing interest owing to their crystal and electronic structural nuances that play a role in seemingly superior electrochemical performance. These materials require a high valent ion, such as Sb5+or Te6+, or a large size discrepancy betwe their honeycomb ordering. In a previous study, a O’3-Na3Ni1.5TeO6composition was studied, with the intent of substituting a small amount of Na+for Ni2+within the transition-metal layer of the material. This substitution resulted in a suppression of MO2layer gliding during cycling that led to superior electrochemical performance of the material. The material demonstrated a singular phase transition from O’3 to P’3 once a small amount of sodium was extracted without the presence of sodium ordering in the interlayer space and a potentiostatic hold was required to reinsert enough Na+to form the original O’3 structural. The singular phase transition and lack of sodium ordering in the material during cycling resulted in a single sloping plateau voltage curve that is promising towards developing practical layered NaxMO2cathode for sodium batteries. Additionally, the P’3-layered structure allowed for superior Na+diffusion in the interlayer space leading to good rate capability. From the results from the O’3-Na3Ni1.5TeO6phase, the next step became to assess whether a similar substitution strategy could be applied to a material that started with trigonal prismatic sites in the interlayer space to take advantage of the fast Na+diffusion in the interlayer space from the start of cycling. For this purpose, the P2-Na2Ni2TeO6 material of the same compositional family, which had previously been electrochemically evaluated, was chosen. After considering the charge balance of substituting Na+for Ni2+in this system, the final formula for evaluation is Na2+xNi2-x / 2TeO6(or Na2 / 3+x / 6[Nax / 6Ni2 / 3-x / 6Te1 / 3]O2). Of particular interest for this material was to observe how much sodium can be substituted while maintaining a purely P2 layer stacking as well as if substituting sodium in the MO2layer would induce a shift in the interlayer stacking. This system turns out to be extremely sensitive to the total sodium content in the material; the structure and the electrochemical properties are profoundly impacted by the composition of the pristine material. Elucidating the relationship between starting composition, structure, and electrochemical properties for these materials can guide further efforts of tailoring the performance of NaxMO2layered oxide materials towards enabling a truly competitive low- cost rechargeable sodium battery. Results are shown in Table 1 and Figure 1A - Figure 6F.

[0015] Table 1. Unit cell information obtained from Le Bail Fittin patterns of Na2+xNi2-x / 2TeO6(0 ≤ x ≤ 3). Composition Na2Ni2TeO6Na2.1Ni1.95TeO6Na2.2Ni1.9TeO6Na2.3Ni1.85TeO6Space Group P63 / mcm P63 / mcm P6322 P6322 P6322 Synthesis. The series of P2-layered Na2+xNi2-x / 2TeO6 (0 ≤ x ≤ 0.5) was prepared with a traditional solid-state synthesis. Na2CO3 (Acros Organics, 99.8%), NiO (Alfa Aesar, 99%), and TeO2 (Alfa Aesar, 99.99%) were used as received without further purification as the starting materials. Stochiometric amounts of each precursor were ground in a mortar and pestle until a homogenous powder was obtained. No excess sodium was used at any point in the synthesis of each composition and careful attention was paid to the Na / Ni ratio of the precursor materials. An initial firing of the powder was performed in an alumina boat at 650°C for 12 hours with a 10°C per minute heating and cooling rate. This powder was then reground, pressed into a pellet, and fired at 810°C for 24 hours with a 10°C per minute heating rate and 2°C per minute cooling rate to obtain the final material. All furnace firings were performed in air. X-Ray Diffraction and Refinement. All powder X-ray diffraction measurements were performed with a Rigaku Miniflex diffractometer (Cu Kα radiation). Powder diffraction patterns of all pure phases used for Le Bail refinement were obtained from 10 to 100° 2θ in stepping mode at 0.02° increments with a 2 second pause at each step. Powder diffraction patterns for phase verification that were not refined in any manner were obtained from 10° to 80° 2θ in continuous scanning mode at a scan rate of 5° per minute. Le Bail fitting of each pure phase material was performed with the FullProf software suite to obtain unit cell parameters and ensure proper identification of the space group for each material. All structural depictions were developed with the VESTA 3D structure visualization program. Solid-state Nuclear Magnetic Resonance Spectroscopy.23Na solid-state nuclear magnetic resonance spectroscopy (NMR) spectra were acquired with the pj-MATPASS pulse sequence on a 400 MHz Bruker Avance III HD spectrometer with a Bruker 4 mm HXY probe at a magic angle spinning (MAS) frequency of 8 kHz.32 slices in the F2 dimension and 400 scans per slice were used in the pj-MATPASS pulse sequence. A sequence was used to acquire an initial spectrum with π / 2 pulse length of 2.2 μs optimized on solid NaCl at a power of 80 W. NaCl was used as a secondary shift reference at 7.21 ppm (relative to 1 M NaCl(aq)). These NMR measurements were obtained with a recycle delay of 0.5 s. Hahn echo23Na MAS NMR spectra were recorded with a Bruker 300 Avance spectrometer at 79.47 MHz at spinning frequencies of 28 kHz and 30 kHz. Each material was loaded into a zirconia rotor in an Ar-filled glove box before being loaded into the spectrometer for measurement. A Hahn-echo pulse sequence with a pulse length of 2 µs and a recycle time of D1 = 0.2 s was used for spectrum acquisition. The external reference was a 0.1 M NaCl aqueous solution. Electrode Preparation. Electrodes for galvanostatic cycling were prepared with 70 wt% active material, 20 wt% Denka black as the electronically conductive additive, and 10 wt% polytetrafluoroethylene (PTFE) as the binder. For each electrode, the active material and Denka black were thoroughly ground together in a mortar and pestle before adding in the PTFE to the mixture. The mixture was then ground until a homogenous film was obtained and rolled into a free-standing electrode film. This film was dried at 80°C for at least 12 hours before electrode discs ¼ inch in diameter were punched, weighed, and transferred into an Ar-filled glove box (MBraun) with H2O and O2levels below 0.1 ppm for electrochemical cell assembly. Coin Cell Assembly.2032-coin cells were fabricated with a P2-layered Na2+xNi2-x / 2TeO6 (0 ≤ x ≤ 0.5) electrode composite disc as the cathode, glass-fiber (Whitman) as the separator, and a sodium metal anode.1 M NaClO4 in propylene carbonate (PC): fluoroethylene carbonate (FEC) in a volume ratio of 9:1 was used as the electrolyte for these cells. Galvanostatic cycling measurements were performed with LANHE battery testing units. All electrochemical cycling of the P2-layered Na2+xNi2-x / 2TeO6 (0 ≤ x ≤ 0.5) materials were performed at a C / 20 cycling rate with different voltage cutoffs between 2.5 ≤ V ≤ 4.4 V versus Na+ / Na. Example 4 Computational methodology. Density functional theory (DFT) calculations were performed using the projector augmented wave (PAW) approach in the VASP code. The Perdew-Burke-Ernzerhof (PBE) functional was used for all calculations and a Hubbard U parameter (DFT+U) was applied to Ni to correct for issues associated with electron. Results and Discussion Calculations Pristine Na2Ni2TeO6: The relative energies of the p were studied with DFT calculations of Na2Ni2TeO6supercells containing 8 formula units (Na16Ni16Te8O48). Possible low energy Na / Na vacancy orderings at room temperature of both phases were investigated via Monte Carlo basin hopping swapping in which the position of Na vacancies (VNa) was located using Voronoi polyhedra. For the pristine Na2Ni2TeO6 structures, a multistep procedure was used in which 100 Na / VNaswaps were carried out sequentially at 2000 K, 1000 K and finally, 300 K. After each temperature, the lowest energy structure found was fully optimized and used as the starting input for the next temperature range. The results for the pristine P63 / mcm and P6322 Na2Ni2TeO6 structures is show in Figure 7A-Figure 7C. For the pristine Na2Ni2TeO6structure, at 300 K, the energies of the P63mcm and P6322 structures from the MC swapping process reached a plateau (Figure 7A), with the P63mcm structure resulting in a lower in energy than the P6322 structure. The lowest energy configurations found for both structures were selected and fully optimized to a tighter tolerance with DFT. The lowest energy P6322 structure was found to be 32 meV / formula unit higher in energy than the lowest energy P63 / mcm structure (Figure 7B), which is in good agreement with the experimental XRD result in which the P63 / mcm structure is observed for pristine Na2Ni2TeO6at room temperature, in the absence of Na substitution. The lowest energy P63 / mcm structure contained a 3:1 ratio Na1 to Na2 sites (Figure 7B), whilst the ratio of Na1, Na2 and Na3’ sites in the lowest energy P6322 structure was 2:1:1. The Na1 trigonal prismatic sites are low energy positions in both structures, which share edges with 4 NiO6and 2 TeO6octahedra, minimizing their electrostatic repulsion. The Na2 sites in both structures share a common face with two NiO6 sites. The Na3 sites, which share faces with two TeO6 octahedra, were not present in the lowest energy P63 / mcm structure. This is consistent with the high electrostatic repulsion between Na+and Te6+cations in these configurations. For the P6322 structure, the Na were present in Na3’ sites, which are face sharing with one NiO6 in the layer above (below) and one TeO6in the layer below (above). The electrostatic repulsion of these sites is therefore expected to be intermediate between the Na2 (2 face sharing NiO6) and Na3 (2 face sharing TeO6) sites in the P63mcm structure. Na substituted Na2+xNi2-x / 2TeO6: The impact of Na substitution into the Ni sites of the lowest energy P63 / mcm and P6322 structures was further studied using the MC swapping approach. Two Ni sites in the lowest energy P63 / mcm and P6322 pristine structures were substituted for Na, 1 in each layer.2 additional Na atoms were then randomly added to vacant sites in both structures for charge balance to create a Na-excess Na2.5Ni1.75TeO6 (Na18[Na2Ni14Te8]O48) composition.100 MC swapping steps were performed at 1000 K followed by 100 MC at 300 K. Analogous to the pristine m from the first 100 MC steps at 1000 K was fully optimized and used as the input for the 300 K runs. The results for the Na substituted P63 / mcm and P6322 structures is shown in Figure 8A. At 300 K, the P6322 structure of Na2.5Ni1.75TeO6was found to be lower in energy than the P63 / mcm structure (Figure 8A) from MC swapping, opposite to what was previously found for the pristine Na2Ni2TeO6phase (Figure 7A). The lowest energy P63 / mcm and P6322 phases were fully optimized with tighter DFT settings, and the former phase was found to be 24 meV / formula unit higher than the latter phase (Figure 8B). The change in the phase stability from the P63 / mcm to the P6322 structure is in excellent agreement with experiment, where Na substitution was found to progressively lead to the P6322 phase. There is a tendency for the Na sites in the Ni / Te layer to be coordinated by Na1 sites in the adjacent Na layers, from analysis of the Na positions in the lowest energy Na substituted P63 / mcm to the P6322 structures (Figure 8B),. This ordering creates islands of Na1 sites that help disrupt the long-range Na ordering. The presence of Na in the Ni-Te layer (Na4) also alters the of some of the face sharing Na2 and Na3’ (P6322) sites. To distinguish between when one of the Ni sites in the NiO6-Na-NiO6 or NiO6-Na-TeO6 face sharing configurations is substituted with Na, it is given the symbol ‘b’ (Na2b or Na3’b), whereas the original unsubstituted site is designated as ‘a’ (Na2a or Na3’a) in Figure 8B. The lower electrostatic repulsion between face sharing Na+-Na+configurations compared to Na+-Ni2+configurations is expected to further stabilize these sites. For the lowest energy P6322 structure, all types of sites are present (Na1, Na2a, Na2b, Na3’a and Na3’b) with a preference for Na1 sites. For the P63 / mcm structure all types of sites (Na1, Na2a, Na2b and Na3) are also observed, including the Na3 site. The Na3 TeO6-Na-TeO6 configuration is not altered by Na substitution on the Ni site, and is expected to remain as a high energy site. The preferential lowering in energy of the Na3’b sites in the P6322 structure may further help to disrupt Na ordering, leading to fast Na conduction. Solid-State NMR. The local arrangement of Na sites as a function of Na-excess in Na2+xNi2-x / 2TeO6 was further studied with23Na solid state nuclear magnetic resonance (NMR) (Figure 9A-Figure 9B). For the Na2Ni2TeO6 end member, three isotropic resonances (circles) are observed in Figure 9A at 1125, 552 and –3 ppm. To confirm that the remaining peaks in the spectrum were due to spinning sidebands, spectra were acquired at slower spinning speeds. As the Na-excess concentration increased to Na2.1Ni1.95TeO6, additional peaks (stars) are observed in Figure 9A at 701 and ~ –320 ppm. The 3 peaks previously observed in Na2Ni2TeO6 are still present with decreased intensity. At Na2.2Ni1.9TeO6, the original peaks are absent, leaving a single, intense resonance at 678 ppm, with 2 smaller peaks at –307 and –1 Na2.3Ni1.85TeO6results in a small shift in the dominant peak to 661 ppm. The reduction in the shift is due to the reduction in the number of paramagnetic Ni2+centers in the first and second coordination spheres of Na. The peaks at –300 and –184 ppm are still present with increased intensity Figure 9B. A small peak at 0 ppm is also observed, which is tentatively assigned to diamagnetic impurities on the surface of the cathode particles. First principles NMR parameters of stoichiometric Na2Ni2TeO6: In order to assign the peaks in Figure 9A-Figure 9B to environments within the P63 / mcm and P6322 phases observed via diffraction, first principles calculations were used. The dominant interaction in solid-state23Na NMR spectra containing paramagnetic transition metals is typically the Fermi contact interaction. As demonstrated in previous studies, the Fermi contact interaction of Na and Li transition metal oxide cathodes can be well approximated using DFT calculations. The23Na Fermi contact shifts for the lowest energy stoichiometric and Na substituted P63 / mcm and P6322 structures predicted in the previous section were calculated as shown in Figure 10. Large positive23Na Fermi contact shifts are observed for the edge sharing Na1 sites in both the P63 / mcm (705, 976 and 1232 ppm) and P6322 (1041 ppm) structures in Figure 10 (blue squares). Three distinct shifts are seen for the Na1 sites in the P63 / mcm structure as these sites experience different local displacements and bond lengths in the optimized low energy supercell structure. The Na1 sites with shifts of 705 and 1232 ppm are displaced towards neighboring Na2 and Na3 sites, respectively, whilst the Na1 site with a shift of 976 ppm is located at the center of the site. The Na2 sites, which share faces with two Ni, lead to the lowest shifts in both the P63 / mcm (192 ppm) and P6322 (282 ppm) structures. The Na3’ site in the P6322 structure has an intermediate shift of 695 ppm. With the aid of DFT calculated shifts and the previous XRD refinements, the peak at 1125 ppm in the experimental Na2Ni2TeO6NMR spectrum is assigned to a Na1 site in the P63 / mcm structure. Only a single broad resonance is observed in this region suggesting that the shifts of the distinct Na1 sites present in the static, nominally 0 K DFT calculations are averaged on the NMR timescale. The peak at –3 ppm is tentatively assigned to Na in an Na2 site of P63 / mcm structure. The lower shift observed experimentally compared to DFT (192 ppm) may result from the impact of additional 2nd order quadrupole shifts not included in the current DFT treatment and to the choice of DFT functional. The experimentally observed resonance at 552 ppm does not directly match an observed resonance in the of P63 / mcm structure computed with DFT. The shift of 552 ppm is, however, very close to the average of the shifts of the Na1 (1125 ppm) and Na2 (–3 ppm) where 1125+3 / 2 = 564 ppm. This to Na that is exchanging between neighboring Na1 and Na2 sites at a frequency more rapid than the frequency separation between the peaks. This rapid exchange has been shown to be a common phenomenon in other Na-cathode materials. This result suggests that in the stoichiometric Na2Ni2TeO6 system, there are two subsets of Na ions with different mobilities: Na ions rapidly exchanging between Na1 / Na2 sites on the NMR timescale and static Na1 and Na2 sites. First principles NMR parameters of Na-excess Na2+xNi2-x / 2TeO6: The23Na NMR shifts of the lowest energy Na excess supercells (Figure 8A and Figure 8B) were calculated as shown in Figure 11A. The inclusion of Na into the Ni / Te layer of the Na20Ni14Te8O48 (Na2.5Ni1.75TeO6) P63 / mcm and P6322 structures results in a broad distribution of shifts, particularly for the Na1 (blue square) sites in Figure 11A. This is due to different numbers of Ni2+-O-Na+bond pathway contributions in the first and second coordination spheres of Na to the total Fermi shift. The introduction of Ni / Te layer Na (Na4 sites) leads to new, diamagnetic Na+(4)-O-Na+bond pathway, which do not contribute to the overall Fermi contact shift. Na2 sites still lead to the lowest shifts in the P63 / mcm and P6322 structures, whereas Na3 sites in the P63 / mcm structure (1167 ppm) have larger shifts than Na3a’ (598 – 610 ppm) and Na3b’ (624 ppm) due to different neighboring configurations of Ni2+. Regardless of the site type, Figure 11A shows that all sites in the Na layer (Na1, Na2a, Na2b, Na3, Na3a’ and Na3b’) P63 / mcm and P6322 structures have positive23Na NMR shifts. In the experimental spectrum of Na2.3Ni1.85TeO6, only a single intense resonance is observed at 661 ppm. A average of the shifts for Na layer sites was taken for the P63 / mcm and P6322 structures, resulting in shifts of 684 and 659 ppm. The shifts of both structures are in excellent agreement with the experimental value suggesting that all of the Na sites within the Na layer are being rapidly averaged. An exact assignment of the P63 / mcm or P6322 structures is not possible based solely on the NMR, but as the P6322 phase is the only phase observed by XRD at a composition of Na2.3Ni1.85TeO6, we can assign these Na sites to the Na layer of the P6322 phase. From the DFT computed shifts in Figure 11B, the Na4 sites in the Ni / Te layer are the only environments that result in a negative shift for both the P63 / mcm (–233 ppm) and P6322 (– 222 ppm) structures. This is consistent with previously observed23Na NMR shifts in the Na3Ni1.5TeO6structure (this is also the case for anti-sites in LiNiO2). These sites only contain 3 Ni2+neighbors along 90° Ni2+-O-Na bond pathways. The experimentally observed shift at –300 ppm is therefore assigned to the Na4 site in the Ni / Te layer of the P6322 structure. Each 90° Ni2+-O-Na bond pathway contribution is therefore expecte The experimental shift of –184 ppm is assigned to a Na4 site with 2 Ni2+ neighbors and 1 diamagnetic Na+neighbor. Na-Na first nearest neighbor connections were also observed previously in the Na3Ni1.5TeO6structure This result gives unambiguous evidence of the introduction of Na into the Ni / Te layer of the system which is accompanied by a disordering of the Na layer sites, leading to fast motion. EXEMPLARY ASPECTS In view of the described compositions, devices, systems, and methods, herein below are described certain more particularly described aspects of the inventions. The particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein. Example 1: A method of making a composition, the method comprising sol-gel synthesis, the composition comprising: Na(z)[Na(x)Ni(y)M(1-x-y)]O2 where 0.5 ≤ z ≤ 0.8; 0 ≤ x ≤ 1 / 3; 0 ≤ y ≤ 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced. Example 2: The method of any examples herein, particularly example 1, wherein the composition has an empirical formula Na(z)[Na(x)Ni(y)M(1-x-y)]O2. Example 3: The method of any examples herein, particularly example 1 or example 2, wherein the composition comprises Na(3z)[Na(3x)Ni(3y)M(3-3x-3y)]O6. Example 4: The method of any examples herein, particularly examples 1-3, wherein M is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Al, Sn, Sb, Te, or any combination thereof. Example 5: The method of any examples herein, particularly examples 1-4, wherein M is Te, Bi, Sb, or a combination thereof. Example 6: The method of any examples herein, particularly examples 1-5, wherein M is Te. Example 7: The method of any examples herein, particularly examples 1-6, wherein the composition comprises a sodium excess layered oxide. Example 8: The method of any examples herein, particularly examples 1-7, wherein the composition comprises a P2 layered system. Example 9: The method of any examples herein, pa sodium ions within the transition metal-layer reversibly diffuse to the sodium layer during electrochemical cycling. Example 10: The method of any examples herein, particularly examples 7-8, wherein sodium ions occupy sites within the transition-metal layer of the layered oxide. Example 11: The method of any examples herein, particularly example 10, wherein the sodium layer is disordered. Example 12: The method of any examples herein, particularly examples 1-11, wherein the method comprises a full sol-gel synthesis. Example 13: The method of any examples herein, particularly example 12, wherein the method comprises: solvating a sodium containing precursor, a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent (e.g., citric acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel to form a ground mixture; and sintering the ground mixture to form the composition. Example 14: The method of any examples herein, particularly example 13, wherein the sodium containing precursor is water-soluble. Example 15: The method of any examples herein, particularly examples 13-14, wherein the sodium containing precursor is water-soluble and comprises sodium acetate, sodium hydroxide, sodium oxalate, or a combination thereof. Example 16: The method of any examples herein, particularly examples 13-15, wherein the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble. Example 17: The method of any examples herein, particularly examples 1-11, wherein the method comprises a partial sol-gel synthesis. Example 18: The method of any examples herein, particularly example 17, wherein the method comprises: solvating a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent (e.g., citric acid), in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel in the presence of a sodium containing precursor, to form a ground mixture; and sintering the dried sol-gel to form the composition. Example 19: The method of any examples herein, particularly example 18, wherein the sodium containing precursor comprises sodium carbonate. Example 20: The method of any examples herein, p the nickel containing precursor comprises an oxide, and the method further comprises contacting the nickel containing precursor with an acid (e.g., nitric acid) to digest the nickel containing precursor. Example 21: The method of any examples herein, particularly examples 13-19, wherein the nickel containing precursor is water-soluble. Example 22: The method of any examples herein, particularly example 21, wherein the nickel containing precursor is water-soluble and comprises nickel nitrate. Example 23: The method of any examples herein, particularly examples 13-22, wherein the M containing precursor comprises an oxide, and the method further comprises contacting the M containing precursor with an acid (e.g., nitric acid) to digest the M containing precursor. Example 24: The method of any examples herein, particularly examples 13-22, wherein the M containing precursor is water-soluble. Example 25: The method of any examples herein, particularly example 24, wherein the M containing precursor is water-soluble and comprises a nitrate, an acetate, a sulfate, a chloride, or a combination thereof. Example 26: The method of any examples herein, particularly example 24 or example 25, wherein the M containing precursor is water-soluble and comprises a nitrate. Example 27: The method of any examples herein, particularly examples 24-26, wherein the M containing precursor is water-soluble, M is Te, and the M containing precursor is tellurium nitrate. Example 28: The method of any examples herein, particularly examples 13-27, wherein the nickel containing precursor and the M containing precursor are each water-soluble. Example 29: The method of any examples herein, particularly examples 13-28, wherein the chelating agent is present. Example 30: The method of any examples herein, particularly example 29, wherein the chelating agent comprises citric acid. Example 31: The method of any examples herein, particularly example 29 or example 30, wherein the chelating agent is used to form the gel and ensure intermixing of all of the metal ions. Example 32: The method of any examples herein, particularly examples 13-31, wherein the solvent comprises water. Example 33: The method of any examples herein, p the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble and the solvent comprises water. Example 34: The method of any examples herein, particularly examples 13-33, wherein the method further comprises agitating (e.g., stirring) the solution. Example 35: The method of any examples herein, particularly examples 13-34, wherein sintering comprises heating the ground mixture at a temperature of from 700 to 1200°C for an amount of time of from 6-72 hours, and subsequently cooling to room temperature at a rate of from 0.5 to 20°C per minute. Example 36: The method of any examples herein, particularly example 35, wherein sintering comprises heating the ground mixture at a temperature of from 800 to 850°C. Example 37: The method of any examples herein, particularly example 35 or example 36, wherein sintering comprises heating the ground mixture at the temperature for an amount of time of from 12-24 hours. Example 38: The method of any examples herein, particularly examples 35-37, wherein sintering comprises heating the ground mixture at the temperature for the amount of time, and subsequently cooling at a rate of from 1 to 5°C per minute. Example 39: The method of any examples herein, particularly examples 13-38, wherein sintering comprises heating the ground mixture at a temperature of from 800 to 850°C (e.g., 810°C) for an amount of time of from 12-24 hours, and subsequently cooling at a rate of from 1 to 5°C per minute (e.g., 2°C per minute) to room temperature. Example 40: The method of any examples herein, particularly examples 1-39, wherein the method results in a more homogenous particle composition, morphology and size distribution relative to traditional solid state methods. Example 41: The method of any examples herein, particularly examples 1-40, wherein an electrochemical cell comprising the composition exhibits a smooth voltage curve. Example 42: The method of any examples herein, particularly examples 1-41, wherein the composition exhibits a Na-ion conductivity of 10-5S / cm or more at 297 K. Example 43: The method of any examples herein, particularly examples 1-42, wherein the composition has a mitigated structural transition when cycled in an electrochemical cell, for example as compared to a composition without excess sodium. Example 44: A composition made by the methods of any examples herein, particularly examples 1-43. Example 45: A system comprising the composition examples herein, particularly examples 1-43. Example 46: An article or device comprising the composition made by the methods of any examples herein, particularly examples 1-43. Example 47: The article or device of any examples herein, particularly example 46, wherein the article or device comprises an electrode, such as a cathode. Example 48: The article or device of any examples herein, particularly example 46 or example 47, wherein the article or device comprises an electrochemical cell, such as an electrochemical cell comprising the electrode of any examples herein, particularly example 46. Example 49: The article or device of any examples herein, particularly examples 46-48, wherein the article or device comprises an energy storage device, such as a battery, for example an energy storage device comprising the electrode of any examples herein, particularly example 47. Example 50: The article or device of any examples herein, particularly examples 46-49, wherein the article or device comprises a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising the electrode of any examples herein, particularly example 47. Example 51: The article or device of any examples herein, particularly examples 46-50, wherein the article or device comprises a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechargeable battery comprising the electrode of any examples herein, particularly example 47. Example 52: The article or device of any examples herein, particularly examples 48-51, wherein the composition has a mitigated structural transition when cycled, for example as compared to a composition without excess sodium. Example 53: The article or device of any examples herein, particularly examples 48-52, wherein the article or device exhibits extended cycle life, for example as compared to an article or device comprising a composition without excess sodium. Example 54: A method of use of the composition made by the methods of any examples herein, particularly examples 1-43. Example 55: The method of any examples herein, particularly example 54, wherein the method comprises using the composition in an electrode, such as a cathode. Example 56: The method of any examples herein, particularly example 54 or example 55, wherein the method comprises using the composition in an electrochemical cell, such as an electrochemical cell using the electrode of any examples herein, particularly example 55. Example 57: The method of any examples herein, p the method comprises using the composition in an energy storage device, such as battery, for example an energy storage device using the electrode of any examples herein, particularly example 55. Example 58: The method of any examples herein, particularly examples 54-57, wherein the method comprises using the composition in a battery, such as a sodium ion battery and / or a rechargeable battery, for example a battery comprising the electrode of any examples herein, particularly example 55. Example 59: The method of any examples herein, particularly examples 54-58, wherein the method comprises using the composition in a rechargeable battery, such as a rechargeable sodium ion battery, for example a rechargeable battery comprising the electrode of any examples herein, particularly example 55. Example 60: A battery comprising the composition made by the methods of any examples herein, particularly examples 1-43. Example 61: The battery of any examples herein, particularly example 60, wherein the battery is a sodium ion battery and / or a rechargeable battery. Example 62: A system or article comprising one or more of the batteries of any examples herein, particularly example 60 or example 61. Example 63: The system or article of any examples herein, particularly example 62, wherein the system or article comprises an electronic device, such as a portable electronic device, a laptop, a watch, or a cell phone. Example 64: The system or article of any examples herein, particularly example 62 or example 63, the system or article comprises a short range electric vehicle, such as an e-bike or scooter. Example 65: The system or article of any examples herein, particularly examples 62-64, wherein the system or article comprises a large-scale energy storage system. Other advantages which are obvious and which are inherent to the invention will be evident to one skilled in the art. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. The methods of the appended claims are not limited described herein, which are intended as illustrations of a few aspects of the claims and any methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative method steps disclosed herein are specifically described, other combinations of the method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein or less, however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated.

Claims

CLAIMS What is claimed is:

1. A method of making a composition, the method comprising sol-gel synthesis, the composition having an empirical formula comprising: Na(z)[Na(x)Ni(y)M(1-x-y)]O2where 0.5 ≤ z ≤ 0.8; 0 ≤ x ≤ 1 / 3; 0 ≤ y ≤ 1; and M is a 3d or 4d transition-metal, Al, Sn, Sb, Te, or a combination thereof; where z, x, y, and M are selected such that the composition is charge balanced.

2. The method of claim 1, wherein the composition comprises Na(3z)[Na(3x)Ni(3y)M(3-3x-3y)]O6.

3. The method of claim 1, wherein M is Te, Bi, Sb, or a combination thereof.

4. The method of claim 1, wherein M is Te.

5. The method of claim 1, wherein the composition comprises a sodium excess layered oxide.

6. The method of claim 1, wherein the composition comprises a P2 layered system.

7. The method of claim 1, wherein the method comprises a full sol-gel synthesis, wherein the method comprises: solvating a sodium containing precursor, a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent, in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel to form a ground mixture; and sintering the ground mixture to form the composition.

8. The method of claim 7, wherein the sodium containing precursor is water-soluble.

9. The method of claim 7, wherein the sodium contain comprises sodium acetate, sodium hydroxide, sodium oxalate, or a combination thereof.

10. The method of claim 7, wherein the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble.

11. The method of claim 1, wherein the method comprises a partial sol-gel synthesis, wherein the method comprises: solvating a nickel containing precursor (when y is > 0), and a M containing precursor (when y is < 1), optionally in the presence of a chelating agent, in a solvent to form a solution; heating the solution to evaporate the solvent and form a gel; heating the gel to form a dried sol-gel; grinding the dried sol-gel in the presence of a sodium containing precursor, to form a ground mixture; and sintering the dried sol-gel to form the composition.

12. The method of claim 11, wherein the sodium containing precursor comprises sodium carbonate.

13. The method of claim 7 or claim 11, wherein the nickel containing precursor comprises an oxide, and the method further comprises contacting the nickel containing precursor with an acid (e.g., nitric acid) to digest the nickel containing precursor; or wherein the nickel containing precursor is water-soluble.

14. The method of claim 7 or claim 11, wherein the M containing precursor comprises an oxide, and the method further comprises contacting the M containing precursor with an acid (e.g., nitric acid) to digest the M containing precursor; or wherein the M containing precursor is water-soluble.

15. The method of claim 7 or claim 11, wherein the chelating agent is present.

16. The method of claim 7 or claim 11, wherein the solvent comprises water.

17. The method of claim 7 or claim 11, wherein the sodium containing precursor, the nickel containing precursor, and the M containing precursor are each water-soluble and the solvent comprises water.

18. The method of claim 7 or claim 11, wherein sinteri mixture at a temperature of from 700 to 1200°C for an amount of time of from 672 hours, and subsequently cooling to room temperature at a rate of from 0.5 to 20°C per minute.

19. A composition made by the methods of any one of claims 1-18.

20. A battery comprising the composition made by the methods of any one of claims 1-18.

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