compositions

Abstract

Disclosed herein are layered transition metal oxide materials. Also disclosed herein are electrodes comprising layered transition metal oxide materials. In addition, also disclosed herein is the use of such layered transition metal oxide materials in the manufacture of electrodes and electrochemical cells, and processes for making such layered transition metal oxide materials and electrodes.

Description

COMPOSITIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority from Australian Provisional Patent Application No 2024901585 filed on 28 May 2024, and Australian Provisional Patent Application No 2025901023 filed on 28 March 2025, the contents of which are incorporated herein by reference in their entirety.TECHNICAL FIELD

[0002] The present disclosure relates to layered transition metal oxide materials. The present disclosure also relates to electrodes comprising layered transition metal oxide materials. In addition, the present disclosure relates to the use of such layered transition metal oxide materials in the manufacture of electrodes and electrochemical cells. The present disclose also relates to processes for making such layered transition metal oxide materials and electrodes.BACKGROUND

[0003] Despite rapid advancements in the metal-ion battery (Li ion battery (LIB) and sodium ion battery (SIB)) industries, technological constraints have limited progress in the fabrication of existing cathodes. SIBs recently have attracted attention owing to their low-cost, high-energy densities, and sustainability. Further advantages include reduction or elimination of toxicity (from Li, Co) and overcoming geographical distribution issues (Li).

[0004] Layered transition metal oxides (TMOs) incorporating alkali metals represent a class of cathode materials with the potential to increase energy densities and lifetime, reduce costs, and improve safety for electric vehicles and grid storage. The fabrication processes for layered TMOs as cathodes in LIBs and SIBs typically are multiple-stage and involve the use of high temperatures (>700°C) over extended times (>24 hours); grinding; addition of liquid medium, binding, and conductive agents; and slurry casting (100-200 pm thickness) on a current collector. These result in high costs, significant environmental impact, safety issues, quality control issues, and diminished performance. Further, there are several main shortcomings of the existing generation of batteries that reduce performance and these are related to the fabrication of the TMO and the use of a slurry:(a) inhomogeneous TMO stoichiometry owing to variable Na intercalation capacity and consequent inconsistent valence ratio (or metal vacancy concentration);(b) inhomogeneous TMO mineralogy owing to phase transformation from the layered structure to a spinel structure;(c) inhomogeneous TMO microstructure owing to inconsistent distribution of the TMO (the active material) in the slurry;(d) blockage of the TMO surface (the active sites) and consequent Na redox during charge and discharge by the non-conductive binding agent;(e) blockage of charge transfer between the TMO and the current collector by the binding agent; or(f) blockage of charge transfer between the conductive agent and the current collector by the binding agent.

[0005] Elimination of two slurry deposition by replacement using direct deposition on a substrate (without binder or conductive agent) reduces the shortcomings to the preceding (1) and (2). The most recent such alternative approach to fabricate TMOs involves multiple- stage molten salt electrodeposition of Na-ion cathodes, which requires a highly corrosive Na / transition metal ratio in the range of -300; heating at 350°C for 2 hours under air, argon, or nitrogen; and annealing at 900°C for 6 hours.

[0006] The other two alternatives are pulsed laser deposition and radio frequency magnetron sputtering to deposit polytypes (different stacking sequences of the same structures) of LixTMCh and NaxTMCh and analogue polyanion compounds (typically oxysulphates and oxyphosphates). These methods have the disadvantages of requiring heating (>750°C), limitations in cathode thicknesses (<750 nm), and slow growth rates (tens of nm per hour). These limitations are associate with increased production costs, hindrance to scale-up, reduced cathode structural stability, and performance shortcomings.

[0007] It would be beneficial to develop a process for forming TMOs and electrodes comprising cathode materials based on TMOs which provides an alternative to the above process and avoid one or more of the aforementioned limitations. The present inventors have surprisingly discovered a new cathode material and developed a superior cathode fabrication process which provides for an improved cathode designs, and lower-cost materials and processes.

[0008] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.SUMMARY

[0009] The present disclosure relates to cathode materials and cathodes comprising said cathode material. In some embodiments, at least a portion of the cathode material is a metal oxide. In some embodiments, at least a portion of the cathode material is a metal oxide incorporating an alkali metal cation. In some embodiments, at least a portion of the cathode material is a transition metal oxide. In some embodiments, at least a portion of the cathode material is a transition metal oxide incorporating an alkali metal cation. In some embodiments, at least a portion of the cathode material is a layered transition metal oxide. In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation. In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of birnessite. In some embodiments, at least a portion of the cathode material has a crystal structure that is isomorphous with that of birnessite. In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation with a crystal structure that is substantially isomorphous with that of birnessite. In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation with a crystal structure that is isomorphous with that of birnessite. In some embodiments, the cathode material is substantially anhydrous. In some embodiments, the cathode material is anhydrous. In some embodiments, the cathode material is anhydrous. In some embodiments, the cathode material comprises less than 1 %w / w water.

[0010] In a first of the preset disclosure, there is provided a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0011] In some embodiments, there is provided a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein: at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.

[0012] In some embodiments, there is provided a cathode material comprising a layered transition metal oxide, wherein: the layered transition metal oxide is of formula (I):CcM1zM2yM3xM4wO2,C is one or more alkali metal cations;0 < c < 1.30;M1, M2, M3, and M4are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0 < z < 1.0;0 < y < 1.0;0 < x < 1.0;0 < w < 1.0; and z+y+x+w < 1.0.

[0013] In a second aspect of the present disclosure, there is provided a cathode comprising: a cathode material as described herein; and a current collector.

[0014] In a third aspect of the present disclosure, there is provided a cathode comprising: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; anda current collector, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0015] In a fourth aspect of the present disclosure, there is provided a cathode for a rechargeable battery comprising: a cathode material as described herein; and a current collector.

[0016] In a fifth aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode material as described herein.

[0017] In some embodiments, there is provided an electrochemical cell comprising a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0018] In a sixth aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode material powder as described herein.

[0019] In a seventh aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode as described herein.

[0020] In an eighth aspect of the present disclosure, there is provided the use of the cathode material as described herein in the manufacture of a cathode.

[0021] In a ninth aspect of the present disclosure, there is provided the use of the cathode material as described herein in the manufacture of an electrochemical cell.

[0022] In an tenth aspect of the present disclosure, there is provided the use of the cathode as described in the manufacture of an electrochemical cell.

[0023] Cathodes or cathodes comprising the cathode material described herein may offer improvements in terms of capacity, energy density, power density, and / or cycling stability. The inventors have surprisingly and discovered that, in some aspects or embodiments described herein, the cathode material described herein can have a high alkali metal cation content. Beneficially, the higher alkali metal content increases the number of available charge carriers, leading to improved capacity and higher energy density, which is key performance metric for next-generation batteries.

[0024] Further, in some aspects or embodiments described herein, the inventors have surprisingly discovered the cathode material described herein has a low water content and / or hydroxide ion content thereby reducing the detrimental impact that the presence of water has on cathode materials during electrochemical operation.

[0025] Furthermore, the cathode material described herein is compatible with a wide variety of current collector and / or substrates, for example nickel foam, aluminium foil, carbon foam. In addition, in some aspects or embodiments described herein, the cathode film thickness and / or the mass loading of the cathode material can be may be controlled. This may provide for improvements in electrode conductivity, capacity, gravimetric energy density, and cycling stability (Coulombic efficiency).BRIEF DESCRIPTION OF DRAWINGS

[0026] Whilst it will be appreciated that a variety of embodiments disclosed herein may be used, described herein are a number of examples with reference to the following drawings:Figure 1 : Calculated ternary Na-Mn-EEO Pourbaix diagram, highlighting pH-voltage pathway as a pathway to obtain the stoichiometric NaMnO2.Figure 2: Calculated quaternary Mn-Fe-Na-EEO Pourbaix diagram, highlighting pH- voltage pathway as a pathway to achieve Na-rich Nai.2Fe2+o.4Mn4+o.502.Figure 3: Photographs of the single TMOs with different Na stoichiometries deposited on fluoride-tin oxide, carbon foam, ferrous alloy, and aluminium foil current collectors.Figure 4: Left: SEM, Top Right: TEM, HRTEM, and Bottom Right: STEM images ofpowder of 2D nanosheet architecture.Figure 5: Summary of electrochemical performances of sodium-ion battery cathode materials, operating voltages, capacities, and energy densities (03 and P2 are polytypes) known in the art and of cathode material as described herein.Figure 6: Galvanostatic diagram showing charge / discharge capacities of Na-rich cathodes (Nai.iMn02) in a half-coin cell configuration with Na metal as anode at 0.1 C charge / discharge rates (10 hours charge and 10 hours discharge times).Figure 7: Galvanostatic diagram showing charge / discharge capacities of Na-rich cathodes (Nai.iMnO2) in a half-coin cell configuration with Na metal as anode at 0.1 C charge / discharge rates (10 hours charge and 10 hours discharge times).Figure 8: Galvanostatic diagram showing charge / discharge capacities of Na-rich cathodes (Nai.iMnCh) in a half-coin cell configuration with Na metal as anode at 1 C charge / discharge rates (1 h charge and 1 h discharge times)Figure 9: Charge / discharge capacity retention of Na-rich cathodes in a half-coin cell configuration with Na metal as anode at 1 C charge / discharge rates (1 h charge and 1 h discharge times) and potential window ranging from 1.5 V to 4.5 V vs Na / Na+(black line shows result for Nai.iMnCh; red line shows result for NaojvMnCh).Figure 10: Aberration-corrected (AC) and high-resolution (HR) transmission electron microscopy (TEM) images of the layered structure of nanocrystalline NaxMnCh cathode material deposited on a current collector.Figure 11 : First-cycle galvanostatic charge / discharge capacities of the single TMO (NaojvMnCh) and binary TMO (Na1.2Feo.4Mno.5O2) at 0.1 C rates (10 hours charge and 10 hours discharge times) which again show significantly increased charge and discharge capacities.Figure 12: First- and second-cycle galvanostatic charge / discharge capacities of the binary TMO (Na1.2Feo.4Mno.5O2) at 0.1 C (10 hours charge and 10 hours discharge times).Figure 13: Second- and third-cycle galvanostatic charge / discharge capacities of the Mo-containing binary TMO NaxMoo.1Mno.9O2 at 0.1 C (10 hours charge and 10 hours discharge times).Figure 14: left: ICP-MS and EDS results showing concentrations of Na in Nao.3?Mn02 and Nai.iMnO2 electrodes; right: Corresponding XRD patterns (middle images) and laser Raman microspectra patterns (right images) of as-synthesised cathode materials. Figure 15: Electrochemical performances of Na0.37MnO2 at slow and high performance rates and potential window ranging from 2.0 V to 4.2 V vs Na / Na+.Figure 16: Electrochemical performances of Nal.lMnO2 at slow and high performance rates and potential window ranging from 2.0 V to 4.2 V vs Na / Na+. Figure 17: Electrochemical performances of Nai+xFexMm-xCh at slow and high performance rates and potential window ranging from 2.0 V to 4.2 V vs Na / Na+. Figure 18: X-ray diffraction patterns for experimental high-Na Nai.iMnCb after a single charge / discharge cycle (top) and reference pattern for NaxMnCh P / 2H2O, where 0 < x < 1 (bottom).Figure 19: X-ray diffraction patterns for experimental low-Na NatuvMnCh after a single charge / discharge cycle (top) and reference pattern for P2-type monoclinic NaxMnCh, where 0 < x < 1 (bottom).Figure 20: Fourier transform infrared photospectrometry (FTIR) spectra for P2-type monoclinic NatuvMnCh and Nai.iMnCh; the key observation is the absence of the large and broad H2O stretching vibration for H-0 at -3000 nm, confirming the absence of water in both experimental structuresFigure 21 : XRD patterns of the Fe-containing binary TMO synthesised according to the relevant high-Na salt indicated on the Pourbaix diagram (Na1.2Feo.4Mno.5O2 (black line)) and Mo-containing TMO NaxMoo.1Mno.9O2 (red line).Figure 22: Thermogravimetric and derivative thermogravimetric (DTG) results showing respective changes in mass and rate of changes in mass, as a function of temperature in air atmosphere for Nai.iMnCb deposited on a carbon foam. The negligible mass loss in the TGA curve confirms the minimal structural water loss of -0.7 wt% = 6.33 X 10-5mol.Figure 23: Solid-state nuclear magnetic resonance (ssNMR) results of low-Na Nao.3?Mn02 and high-Na Nai.iMnCb in different charge state (OCV = open circuit voltage; C4.2 = charge up to 4.2 V v Na / Na+; C4.5 = charge up to 4.5 V vs Na / Na+; D2.0 = charge up to 4.2 V vs Na / Na+and then discharge to 2.0 V vs Na / Na+; DI.5 = charge up to 4.2 V vs Na / Na+and then discharge to 1.5 V vs Na / Na+).Figure 24: Rate capability (at different C rates), Nyquist plot, and cyclic voltammogram of binary NaxMnyMozO2 batteries.Figure 25: Cyclic galvanostatic charge / discharge, capacity retention for 140 cycles, cyclic voltammograms, and Nyquist plot of the NaxMnyFexMo / Cb batteries.Figure 26: Na (Mn'f) Mn2+)O2 electrodes: Galvanostatic charge / discharge curves of low (Left: 2-4 mg cm2) and high (Right: 16-20 mg cm'2) mass loadings.DESCRIPTION OF EMBODIMENTSGeneral Terms

[0027] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments. It is understood that other embodiments may be utilised and structural changes may be made without departing from the scope of the present disclosure.

[0028] With regards to the definitions provided herein, unless stated otherwise, or implicit from context, the defined terms and phrases include the provided meanings. Unless explicitly stated otherwise, or apparent from context, the terms and phrases below do not exclude the meaning that the term or phrase has acquired by a person skilled in the relevant art. The definitions are provided to aid in describing particular embodiments, and are not intended to limit the claimed invention, because the scope of the invention is limited only by the claims. Furthermore, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0029] All publications discussed and / or referenced herein are incorporated herein in their entirety.

[0030] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

[0031] Throughout this disclosure, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group of compositions of matter shall be taken to encompass one and a plurality (i.e., one or more) of those steps, compositions of matter, groups of steps or groups of compositions of matter. Thus, as used herein, the singular forms “a”, “an” and “the” include plural aspects unless the context clearly dictates otherwise. For example, reference to “a” includes a single as well as two or more; reference to “an” includes a single as well as two or more; reference to “the” includes a single as well as two or more and so forth.

[0032] Those skilled in the art will appreciate that the disclosure herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the disclosure includes all such variations and modifications. The disclosure also includes all of the examples, steps, features, methods, compositions, coatings, processes, and coated substrates, referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features.

[0033] The term “and / or”, e.g., “X and / or Y” shall be understood to mean either “X and Y” or “X or Y” and shall be taken to provide explicit support for both meanings or for either meaning.

[0034] As used herein, the phrase “at least one of’, when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, “at least one of’ means any combination of items or number of items may be used from the list, but not all of the items in the list may be required. In some cases, “at least one of item A, item B, and item C” may mean, for example and without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0035] As used herein, the term “about”, unless stated to the contrary, typically refers to + / - 10%, for example + / - 5%, of the designated value.

[0036] It is to be appreciated that certain features that are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination.

[0037] Throughout the present specification, various aspects and components of the invention can be presented in a range format. The range format is included for convenience and should not be interpreted 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, unless specifically indicated. For example, description of a range such as from 1 to 5 should be considered to have specificallydisclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 5, from 3 to 5 etc., as well as individual and partial numbers within the recited range, for example, 1, 1.5, 2, 2.2, 3, 4, 4.75, and 5, unless where integers are required or implicit from context. This applies regardless of the breadth of the disclosed range. Where specific values are required, these will be indicated in the specification.

[0038] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0039] The reference to “substantially free” generally refers to the absence of that compound or component in the composition other than any trace amounts or impurities that may be present, for example this may be an amount by weight % in the total composition of less than about 3%, 2% 1%, 0.1%, 0.01%, 0.001%, or 0.0001%.

[0040] Herein “weight %” may be abbreviated to “wt%” or “%w / w”.

[0041] In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments. It is understood that other embodiments may be used and structural changes or adaptions to one or more methods or processes, may be made without departing from the scope of the present disclosure.Cathode material

[0042] The present disclosure relates to cathode materials and cathodes comprising said cathode material.

[0043] In some embodiments, the cathode material comprises one or more transition metal cations of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the cathode material comprises one or more transition metal cations of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the cathode material comprises one or more transition metal cations of elements selected from Mn, Fe, Ni, and Mo.

[0044] In some embodiments, at least a portion of the cathode material is a metal oxide. In some embodiments, the metal oxide comprises one or more transition metal cations of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the metal oxide comprises one or more transition metal cations of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the metal oxide comprises one or more transition metal cations of elements selected from Mn, Fe, Ni, and Mo.

[0045] In some embodiments, at least a portion of the cathode material is a metal oxide incorporating an alkali metal cation. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Li+, Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Li+, Na+, K+and combinations thereof. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, K+and combinations thereof. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, Li+and combinations thereof. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Nat In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Lit In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Kt

[0046] In some embodiments, at least a portion of the cathode material is a transition metal oxide. In some embodiments, the transition metal oxide comprises one or more transition metal cations of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the transition metal oxide comprises one or more transition metal cations of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the transition metal oxide comprises one or more transition metal cations of elements selected from Mn, Fe, Ni, and Mo.

[0047] In some embodiments, at least a portion of the cathode material is a transition metal oxide incorporating an alkali metal cation. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Li+, Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the transition metaloxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Li+, Na+, K+and combinations thereof. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, K+and combinations thereof. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, Li+and combinations thereof. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Na+. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Li+. In some embodiments, the transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is K+.

[0048] In some embodiments, at least a portion of the cathode material is a layered transition metal oxide. In some embodiments, the layered transition metal oxide comprises one or more transition metal cations of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the layered transition metal oxide comprises one or more transition metal cations of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the layered transition metal oxide comprises one or more transition metal cations of elements selected from Mn, Fe, Ni, and Mo.

[0049] In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Li+, Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is selected from Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Li+, Na+, K+and combinations thereof. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, K+and combinations thereof. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations selected from Na+, Li+and combinations thereof. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprisesone or more alkali metal cations is Nat In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Lit In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Kt

[0050] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of birnessite.

[0051] In some embodiments, at least a portion of the cathode material has a crystal structure that is isomorphous with that of birnessite.

[0052] In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation with a crystal structure that is substantially isomorphous with that of birnessite.

[0053] In some embodiments, at least a portion of the cathode material is a layered transition metal oxide incorporating an alkali metal cation with a crystal structure that is isomorphous with that of birnessite.

[0054] In some embodiments, the cathode material is substantially anhydrous.

[0055] In some embodiments, the cathode material is anhydrous.

[0056] In some embodiments, the cathode material comprises less than 1 %w / w water.

[0057] In a first aspect of the preset disclosure, there is provided a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0058] In some embodiments, there is provided a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein: at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.Birnessite crystal structure

[0059] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of birnessite. A person skilled in the art would understand that isomorphous solids are solids that have substantially the same crystal structure but different chemical compositions. Further, in the context of the present application, a person skilled in the art will appreciate that the term “substantially isomorphous” means that the crystal structure is substantially the same, but the structural dimensions may vary. A person skilled in the art would also appreciate that birnessite is nominally defined as NaMnCh.nffcO, and with a stoichiometry defined as (Nao vCao 3)Mn?Oi42.8H2O. In one or more embodiments, it will be further understood that layered transition metals of the present application are substantially isomorphous with the crystal structure that is found in birnessite compound of manganese oxide but that the layered transition metals of the present application do not necessarily contain birnessite.

[0060] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-birnessite.

[0061] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 12.5° ± 0.2°.

[0062] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 25° ± 0.2°.

[0063] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 37° ± 0.2°.

[0064] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° and at about 25° ± 0.2°.

[0065] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° and at about 37° ± 0.2°.

[0066] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 25° ± 0.2° and at about 37° ± 0.2°.

[0067] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-bimessite characterised by an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2°, at about 25° ± 0.2°, and at about 37° ± 0.2°.

[0068] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of 5-birnessite, wherein 5-bimessite has lattice parameters of about: a = 0.517 nm | b = 0.285 nm,| c = 0.733 nm, an angle of about 103.18°, and an interlaying spacing of about 0.733 nm.Bimessite in layered transition metal oxide

[0069] In some embodiments, the portion of the layered transition metal oxide that is substantially isomorphous with that of birnessite (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999. In some embodiments, the portion of the layered transition metal oxide that is substantially isomorphous with that of birnessite (% w / w based on the total weight of the layered transition metal oxide) is less than about: 99.999, 99.995, 99.99, 99.95, 99.9, 99.5, 99,98, 97, 96, 95, 94, 93, 92, 91, or 90, 85, 80, 75, 70, 65 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5. In some embodiments, the portion of the layered transition metal oxide that is substantially isomorphous with that of bimessite (% w / w based on the total weight of the layered transition metal oxide) may be in a range provided by any two of these upper and / or lower values, for example between about 20 and about 99.999. In some embodiments, at least 5 %w / w of the layered transition metal oxide is isomorphous with bimessite. In some embodiments, at least 20 %w / w of the layered transition metal oxide is isomorphous with bimessite. In some embodiments, at least 50 %w / w of the layered transition metal oxide is isomorphous with bimessite. In some embodiments, at least 70 %w / w of the layered transition metal oxide is isomorphous with bimessite. In some embodiments, at least 80 %w / w of the layered transition metal oxide is isomorphous with bimessite.

[0070] In some embodiments, at least a portion of the layered transition metal oxide has an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 12.5° ± 0.2° 29. In some embodiments, the portion of the layered transition metal oxide that has an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° 29 (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 29, 25, 39, 35, 49, 45, 59, 55, 69, 65, 79, 75, 89, 85, 99, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999.

[0071] In some embodiments, at least a portion of the layered transition metal oxide has an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 25° ± 0.2° 29. In some embodiments, the portion of the layered transition metal oxide that has an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 25° ± 0.2° 29 (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 29, 25, 39, 35, 49, 45, 59, 55, 69, 65, 79, 75, 89, 85, 99, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999.

[0072] In some embodiments, at least a portion of the layered transition metal oxide has an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 37° ± 0.2° 29. In some embodiments, the portion of the layered transition metal oxide that has an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 37° ± 0.2° 29 (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 29, 25,30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999.

[0073] In some embodiments, at least a portion of the layered transition metal oxide has an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° and 25° ± 0.2°. In some embodiments, the portion of the layered transition metal oxide that has an X- ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° and 25° ± 0.2° (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999.

[0074] In some embodiments, at least a portion of the layered transition metal oxide has an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2°, 25° ± 0.2°, and 37° ± 0.2° 29. In some embodiments, the portion of the layered transition metal oxide that has an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2°, 25° ± 0.2°, and 37° ± 0.2° 29 (% w / w based on the total weight of the layered transition metal oxide) is about, or greater than about: 29, 25, 39, 35, 49, 45, 59, 55, 69, 65, 79, 75, 89, 85, 99, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999.Layered transition metal oxide in cathode material

[0075] In some embodiments, the layered transition metal oxide content in the cathode material (% w / w based on the total weight of the cathode) is about, or greater than about: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 50, 55, 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999. In some embodiments, the layered transition metal oxide content in the cathode material (% w / w based on the total weight of the cathode) is less than about: 99.999, 99.995, 99.99, 99.95, 99.9, 99.5, 99, 98, 97, 96, 95, 94, 93, 92, 91, or 90, 85, 80, 75, 70, 65 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5. In some embodiments, the layered transition metal oxide content in the cathode material (% w / w based on the total weight of the cathode) may be in a range provided by any two of these upper and / or lower values, for example between about 5 and about 99.999, between about 50 and about 99.999. In some embodiments, at least 5 %w / w of the cathode material is the layered transition metal oxide. In some embodiments, at least 50 %w / w of the cathode material is the layered transition metal oxide. In some embodiments, at least 70 %w / w of the cathode material is the layered transitionmetal oxide. In some embodiments, at least 50 %w / w of the cathode material is the layered transition metal oxide. In some embodiments, at least 80 %w / w of the cathode material is the layered transition metal oxide.

[0076] In some embodiments, at least 5 %w / w of the cathode material is the layered transition metal oxide and at least 5 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 50 %w / w of the cathode material is the layered transition metal oxide and at least 20 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 50 %w / w of the cathode material is the layered transition metal oxide and at least 50 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 75 %w / w of the cathode material is the layered transition metal oxide and at least 75 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 90 %w / w of the cathode material is the layered transition metal oxide and at least 90 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 95 %w / w of the cathode material is the layered transition metal oxide and at least 95 %w / w of the layered transition metal oxide is isomorphous with birnessite.Anhydrous

[0077] In some embodiments, the layered transition metal oxide is substantially anhydrous. In some embodiments, the layered transition metal oxide is anhydrous. In the context of the present application, anhydrous is defined to mean less than 1.5 %w / w loss of mass at 400 °C.

[0078] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002, 0.001, 0.0009, 0.0008, 0.0007, 0.0006, 0.0005, 0.0004, 0.0003, 0.0002, or 0.0001. In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 1.

[0079] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 5. In some embodiments, the water content in the layered transition metal oxide (% w / w based on the totalweight of the layered transition metal oxide) is less than about 4. In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 3. In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 2.

[0080] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 1.5.

[0081] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 1.

[0082] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 0.5.

[0083] In some embodiments, the water content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 0.1.Dehydroxylated

[0084] In some embodiments, the layered transition metal oxide is substantially dehydroxylated. In some embodiments, the layered transition metal oxide is dehydroxylated. In the context of the present application, dehydroxylated is defined to mean less than 1 %w / w loss of mass at 400 °C.

[0085] In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002, 0.001, 0.0009, 0.0008, 0.0007, 0.0006, 0.0005, 0.0004, 0.0003, 0.0002, or 0.0001. In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 5. In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 4. In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 3. In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less thanabout 2. In some embodiments, the hydroxide ion content in the layered transition metal oxide (% w / w based on the total weight of the layered transition metal oxide) is less than about 1.Alkali metal cations

[0086] In some embodiments, the one or more alkali metal cations is selected from Li+, Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the one or more alkali metal cations is selected from Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, the one or more alkali metal cations is selected from Na+, K+, Li+, and combinations thereof. In some embodiments, the one or more alkali metal cations is selected from K+.

[0087] In some embodiments, the one or more alkali metal cations are selected from Li+, Na+, and combinations thereof. In some embodiments, the one or more alkali metal cations is Li+.

[0088] In some embodiments, the one or more alkali metal cations is selected from Na+.Transition metals

[0089] In some embodiments, the one or more transition metal cations are of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the one or more transition metal cations are of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the one or more transition metal cations are of elements selected from Mn, Fe, Ni, and Mo.

[0090] In some embodiments, the layered transition metal oxide comprises two or more transition metal cations. In some embodiments, the two or more transition metal cations are of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the two or more transition metal cations are of elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the two or more transition metal cations are of elements selected from Mn, Fe, Ni, and Mo.

[0091] In some embodiments, the layered transition metal oxide comprises three or more transition metal cations. In some embodiments, the two or more transition metal cations are of elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the three or more transition metal cations are of elements selected fromTi, Mn, V, Fe, Ni, and Mo. In some embodiments, the three or more transition metal cations are of elements selected from Mn, Fe, Ni, and Mo.

[0092] In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of one transition metal element. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of one element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of one element selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of one element selected from Mn, Fe, Ni, and Mo. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of Mn. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of Fe. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of Ni. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of Mo. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of V. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of Ti.

[0093] In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of two transition metal elements. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of two elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of two elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of two elements selected from Mn, Fe, Ni, and Mo.

[0094] In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of three transition metal elements. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of three elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of three elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, thelayered transition metal oxide comprises of one or more transition metal cations of three elements selected from Mn, Fe, Ni, and Mo.

[0095] In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of four transition metal elements. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of four elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of four elements selected from Ti, Mn, V, Fe, Ni, and Mo. In some embodiments, the layered transition metal oxide comprises of one or more transition metal cations of four elements selected from Mn, Fe, Ni, and Mo.Stoichiometric ratio of the alkali metal cation to the transition metal cations

[0096] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is about, or greater than about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, or 1.30. In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is less than about: 1.30, 1.29, 1.28, 1.27, 1.26, 1.25, 1.24, 1.23, 1.22, 1.21, 1.20, 1.19, 1.18, 1.17, 1.16, 1.15, 1.14, 1.13, 1.12, 1.11, 1.10, 1.09, 1.08, 1.07, 1.06, 1.05, 1.04, 1.03, 1.02, 1.01, 1.00, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations may be in a range provided by any two or more of the upper and / or lower amounts.

[0097] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 0.01 to about 1.30.

[0098] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 0.01 to about 1.29.

[0099] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 1.00 to about 1.30.

[0100] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 1.01 to about 1.30.

[0101] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 1.00 to about 1.29.

[0102] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 1.01 to about 1.29.

[0103] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 0.01 to about 1.2.

[0104] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal in the layered transition metal oxide cations is between about 1.01 to about 1.25.

[0105] In some embodiments, the stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is greater than 1.Layered transition metal oxide stoichiometry

[0106] In some embodiments, the layered transition metal oxide is of formula (I): CcM1zM2yM3xM4wO2, wherein:C is one or more alkali metal cations;0 < c < 1.30;M1, M2, M3, and M4are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0<z< 1.0;0<y < 1.0;0<x< 1.0;0 < w < 1.0; and z+y+x+w <1.0.

[0107] In some embodiments, there is provided a cathode material comprising a layered transition metal oxide, wherein: the layered transition metal oxide is of formula (I):CcM1zM2yM3xM4wO2,C is one or more alkali metal cations;0<c< 1.30;M1, M2, M3, and M4are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0<z< 1.0;0<y < 1.0;0<x< 1.0;0 < w < 1.0 z+y+x+w < 1.0; and at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0108] In some embodiments, there is provided a cathode material comprising a layered transition metal oxide, wherein: the layered transition metal oxide is of formula (I):CcM1zM2yM3xM4wO2,C is one or more alkali metal cations;0<c< 1.30;M1, M2, M3, and M4are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0<z< 1.0;0<y < 1.0;0 < x < 1.0;0 < w < 1.0 z+y+x+w < 1.0; at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.

[0109] It will be appreciated that when:M1and M2have different oxidation states, M1and M2may be the same transition metal element or M1and M2may be different transition metal elements; and / or M1and M3have different oxidation states, M1and M3may be the same transition metal element or M1and M3may be different transition metal elements; and / or M1and M4have different oxidation states, M1and M4may be the same transition metal element or M1and M4may be different transition metal elements; and / or M2and M3have different oxidation states, M2and M3may be the same transition metal element or M2and M3may be different transition metal elements; and / or M2and M4have different oxidation states, M2and M4may be the same transition metal element or M2and M4may be different transition metal elements; and / or M3and M4have different oxidation states, M3and M4may be the same transition metal element or M3and M4may be different transition metal elements.

[0110] In some embodiments, the layered transition metal oxide is of formula (II): CcM1zM2yM3xO2, wherein:C is one or more alkali metal cations;1.00 < c < 1.30;M1, M2, and M3, are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0 < z < 1.0;0 < y < 1.0;0 < x < 1.0; and z+y+x < 1.0.

[0111] In some embodiments, the layered transition metal oxide is of formula (III):CcM1zM2yO2, wherein:C is one or more alkali metal cations;1.00 < c < 1.30;M1and M2are independently one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os;0 < z < 1.0;0 < y < 1.0; z+y < 1.0.

[0112] In some embodiments, the layered transition metal oxide is of formula (IV): CCM1ZO2, wherein:C is one or more alkali metal cations;1.00 < c < 1.30;M1is one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu,Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os; and0 < z < 1.0.

[0113] In some embodiments, the layered transition metal oxide is of formula (V): NacMnzM2yO2, wherein:1.00 < c < 1.30;M2is one or more cations of an element selected from Fe, Ni, and Mo;0 < z < 1.0;0 < y < 1.0; and z+y < 1.0.

[0114] In some embodiments, C is selected from Li+, Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, C is selected from Na+, K+, Rb+, Cs+, and combinations thereof. In some embodiments, C is selected from Li+, Na+, K+, and combinations thereof. In some embodiments, C is selected from Li+, Na+, and combinations thereof. In some embodiments, C is Li+. In some embodiments, C is Nat

[0115] In some embodiments, the layered transition metal oxide is of formula (I) of formula (VI):NacMmCb, wherein:1.00 < c < 1.30; and0.7 < z < 1.0.

[0116] In some embodiments, M1, M2, M3and M4are independently selected from one or more cations of an element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, and Os. It will be understood that while M1, M2, M3and M4are selected such that they are different elements, M1, M2, M3and M4individually may be in one or more oxidation states for a selected element.

[0117] In some embodiments, M1, M2, M3and M4are independently selected from Ti2+, Ti3+,Ti4+,V2+,V3+V4+V5+,Cr2+Cr3+Cr4+Cj.5+Cl-6+,MR2+MR3+MR4+MR5+MR6+MR7+Fg2+ Fe3+, Fe4+, Fe5+, Fe6+, Co2+, Co3+, Co4+, Ni2+, Ni3+, Ni4+, Cu1+, Cu2+, Cu3+, Ge2+, Ge3+, Ge4+, Nd3+, Nd4+, Nd5+, MO3+, MO4+, MO5+, MO6+, RU3+, RU4+, RU5+, RU6+, RU7+, Rh3+, Rh4+, Rh5+, Ta3+, Ta4+, Ta5+, W4+, W5+, W6+, Re4+, Re5+, Re6+, Re7+, Os4+, Os5+, Os6+, and Os7+.

[0118] In some embodiments, M1is selected from Ti2+, Ti3+, Ti4+, V2+, V3+, V4+, V5+, Cr2+, Cr3+, Cr4+, Cr5+, Cr6+, Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+, Fe2+, Fe3+, Fe4+, Fe5+, Fe6+, Co2+, Co3+, Co4+, Ni2+, Ni3+, Ni4+, Cu1+, Cu2+, Cu3+, Ge2+, Ge3+, Ge4+, Nd3+, Nd4+, Nd5+, Mo3+, Mo4+, MO5+, MO6+, RU3+, RU4+, RU5+, RU6+, RU7+, Rh3+, Rh4+, Rh5+, Ta3+, Ta4+, Ta5+, W4+, W5+, W6+, Re4+, Re5+, Re6+, Re7+, Os4+, Os5+, Os6+, and Os7+.

[0119] In some embodiments, M1, M2, M3and M4are independently one or more cations of an element selected from Ti, V, Mn, Fe, Ni, and Mo.

[0120] In some embodiments, M1is selected from Ti2+, Ti3+, Ti4+, V2+, V3+, V4+, V5+, Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+, Fe2+, Fe3+, Fe4+, Fe5+, Fe6+, Ni2+, Ni3+, Ni4+, Mo3+, Mo4+, Mo5+, and MO6+.

[0121] In some embodiments, M1is selected from Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, and Mn7+. In some embodiments, M1is selected from Mn3+and Mn4 +. In some embodiments, M1is Mn2+. In some embodiments, M1is Mn3+. In some embodiments, M1is Mn4+.

[0122] In some embodiments, M1is selected from Fe2+, Fe3+, Fe4+, Fe5+, and Fe6+. In some embodiments, M1is selected from Fe2+, Fe3+, and Fe4+. In some embodiments, M1is selected from Fe3+and Fe4+. In some embodiments, M1is Fe2+. In some embodiments, M1is Fe3+. In some embodiments, M1is Fe4+.

[0123] In some embodiments, M1is selected from Ti2+, Ti3+, and Ti4. In some embodiments, M1is selected from Ti3+and Ti4+. In some embodiments, M1is Ti2+. In some embodiments, M1is Ti3+. In some embodiments, M1is Ti4+.

[0124] In some embodiments, M1is selected from V2+, V3+, V4+, and V5+. In some embodiments, M1is selected from V2+, V3+, and V4+. In some embodiments, M1is selected from V3+and V4+. In some embodiments, M1is V2+. In some embodiments, M1is V3+. In some embodiments, M1is V4+.

[0125] In some embodiments, M1is selected from Ni2+, Ni3+, and Ni4+. In some embodiments, M1is selected from Ni3+and Ni4+. In some embodiments, M1is Ni2+. In some embodiments, M1is Ni3+. In some embodiments, M1is Ni4+.

[0126] In some embodiments, M1is selected from Mo3+, Mo4+, Mo5+, and Mo6+. In some embodiments, M1is selected from Mo3+and Mo4+. In some embodiments, M1is Mo3+. In some embodiments, M1is Mo4+.

[0127] In some embodiments, M2is selected from Ti2+, Ti3+, Ti4+, V2+, V3+, V4+, V5+, Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+, Fe2+, Fe3+, Fe4+, Fe5+, Fe6+, Ni2+, Ni3+, Ni4+, Mo3+, Mo4+, Mo5+, and MO6+.

[0128] In some embodiments, M2is selected from Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+. In some embodiments, M2is selected from Mn3+and Mn4 +. In some embodiments, M2is Mn4+.

[0129] In some embodiments, M2is selected from Fe2+, Fe3+, Fe4+, Fe5+, and Fe6+. In some embodiments, M2is selected from Fe2+, Fe3+, and Fe4+. In some embodiments, M2is selectedfrom Fe3+and Fe4+. In some embodiments, M2is Fe2+. In some embodiments, M2is Fe3+. In some embodiments, M2is Fe4+.

[0130] In some embodiments, M2is selected from Ti2+, Ti3+, and Ti4. In some embodiments, M2is selected from Ni3+and Ni4+. In some embodiments, M2is selected from Ti3+and Ti4+. In some embodiments, M2is Ti2+. In some embodiments, M2is Ti3+. In some embodiments, M2is Ti4+.

[0131] In some embodiments, M2is selected from V2+, V3+, V4+, and V5+. In some embodiments, M2is selected from V2+, V3+, and V4+. In some embodiments, M2is selected from V3+and V4+. In some embodiments, M2is V2+. In some embodiments, M2is V3+. In some embodiments, M2is V4+.

[0132] In some embodiments, M2is selected from Ni2+, Ni3+, and Ni4+. In some embodiments, M2is Ni2+. In some embodiments, M2is Ni3+. In some embodiments, M2is Ni4+.In some embodiments, M2is selected from Mo3+, Mo4+, Mo5+, and Mo6+. In some embodiments, M2is selected from Mo3+and Mo4+. In some embodiments, M2is Mo3+. In some embodiments, M2is MO4+.

[0133] In some embodiments, M3is selected from Ti2+, Ti3+, Ti4+, V2+, V3+, V4+, V5+, Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+, Fe2+, Fe3+, Fe4+, Fe5+, Fe6+, Ni2+, Ni3+, Ni4+, Mo3+, Mo4+, Mo5+, and MO6+.

[0134] In some embodiments, M3is selected from Fe2+, Fe3+, Fe4+, Fe5+, and Fe6+. In some embodiments, M3is selected from Fe2+, Fe3+, and Fe4+. In some embodiments, M3is selected from Fe3+and Fe4+. In some embodiments, M3is Fe2+. In some embodiments, M3is Fe3+. In some embodiments, M3is Fe4+.

[0135] In some embodiments, M3is selected from Ti2+, Ti3+, and Ti4. In some embodiments, M3is selected from Ti3+and Ti4+. In some embodiments, M3is Ti2+. In some embodiments, M3is Ti3+. In some embodiments, M3is Ti4+.

[0136] In some embodiments, M3is selected from V2+, V3+, V4+, and V5+. In some embodiments, M3is selected from V2+, V3+, and V4+. In some embodiments, M3is selectedfrom V3+and V4+. In some embodiments, M3is V2+. In some embodiments, M3is V3+. In some embodiments, M3is V4+.

[0137] In some embodiments, M3is selected from Ni2+, Ni3+, and Ni4+. In some embodiments, M3is selected from Ni3+and Ni4+. In some embodiments, M3is Ni2+. In some embodiments, M3is Ni3+. In some embodiments, M3is Ni4+.

[0138] In some embodiments, M3is selected from Mo3+, Mo4+, Mo5+, and Mo6+. In some embodiments, M3is selected from Mo3+and Mo4+. In some embodiments, M3is Mo3+. In some embodiments, M3is Mo4+.

[0139] In some embodiments, M4is selected from Ti2+, Ti3+, Ti4+, V2+, V3+, V4+, V5+, Mn2+, Mn3+, Mn4+, Mn5+, Mn6+, Mn7+, Fe2+, Fe3+, Fe4+, Fe5+, Fe6+, Ni2+, Ni3+, Ni4+, Mo3+, Mo4+, Mo5+, and MO6+.

[0140] In some embodiments, M4is selected from Fe2+, Fe3+, Fe4+, Fe5+, and Fe6+. In some embodiments, M4is selected from Fe2+, Fe3+, and Fe4+. In some embodiments, M4is selected from Fe3+and Fe4+. In some embodiments, M4is Fe2+. In some embodiments, M4is Fe3+. In some embodiments, M4is Fe4+.

[0141] In some embodiments, M4is selected from Ti2+, Ti3+, and Ti4. In some embodiments, M4is selected from Ti3+and Ti4+. In some embodiments, M4is Ti2+. In some embodiments, M4is Ti3+. In some embodiments, M4is Ti4+.

[0142] In some embodiments, M4is selected from V2+, V3+, V4+, and V5+. In some embodiments, M4is selected from V2+, V3+, and V4+. In some embodiments, M4is selected from V3+and V4+. In some embodiments, M4is V2+. In some embodiments, M4is V3+. In some embodiments, M4is V4+.

[0143] In some embodiments, M4is selected from Ni2+, Ni3+, and Ni4+. In some embodiments, M4is selected from Ni3+and Ni4+. In some embodiments, M4is Ni2+. In some embodiments, M4is Ni3+. In some embodiments, M4is Ni4+.

[0144] In some embodiments, M4is selected from Mo3+, Mo4+, Mo5+, and Mo6+. In some embodiments, M4is selected from Mo3+and Mo4+. In some embodiments, M4is Mo3+. In some embodiments, M4is Mo4+.

[0145] In some embodiments, c is about, or greater than about: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05,1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22,1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, or 1.30. In some embodiments, c is less than about: 1.30,1.29, 1.28, 1.27, 1.26, 1.25, 1.24, 1.23, 1.22, 1.21, 1.20, 1.19, 1.18, 1.17, 1.16, 1.15, 1.14, 1.13,1.12, 1.11, 1.10, 1.09, 1.08, 1.07, 1.06, 1.05, 1.04, 1.03, 1.02, 1.01, 1.00, 0.9, 0.8, 0.7, 0.6, 0.5,0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, c may be in a range provided by any two or more of the upper and / or lower amounts, for example, 1.00 < c < 1.30, 1.01 < c < 1.30, 1.00 < c < 1.10, 1.00 < c < 1.15, 1.00 < c < 1.20, 1.00< c < 1.25, 1.00 < c < 1.29, 1.01 < c < 1.10, , 1.01 < c < 1.15, 1.01 < c < 1.20, 1.01 < c < 1.25, 1.01 < c < 1.29, 1.05 < c < 1.10, 1.05 < c < 1.15, 1.05 < c < 1.20, 1.05 < c < 1.25, 1.05 < c <1.29.

[0146] In some embodiments, 0.01 < c < 1.30. In some embodiments, 1.00 < c < 1.30. In some embodiments, 1.01 < c < 1.30. In some embodiments, 1.00 < c < 1.29. In some embodiments, 1.01 < c < 1.29.

[0147] In some embodiments, z is about, or greater than about: 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50. In some embodiments, z is less than about: 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, 1.20, 1.15, 1.10, 1.05, 1.00, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, or 0.00.

[0148] In some embodiments, z may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.00 < z < 1.00, 0.05 < z < 1.00, 0.10 < z < 1.00, 0.15 < z< 1.00, 0.20 < z < 1.00, 0.25 < z < 1.00, 0.30 < z < 1.00, 0.35 < z < 1.00, 0.40 < z < 1.00, 0.45< z < 1.00, 0.50 < z < 1.00, 0.55 < z < 1.00, 0.60 < z < 1.00, 0.65 < z < 1.00, 0.70 < z < 1.00, 0.75 < z < 1.00, 0.80 < z < 1.00, 0.85 < z < 1.00, 0.90 < z < 1.00, 0.95 < z < 1.00.

[0149] In some embodiments, z may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.00 < z < 1.50, 0.05 < z < 1.50, 0.10 < z < 1.50, 0.15 < z< 1.50, 0.20 < z < 1.50, 0.25 < z < 1.50, 0.30 < z < 1.50, 0.35 < z < 1.50, 0.40 < z < 1.50, 0.45< z < 1.50, 0.50 < z < 1.50, 0.55 < z < 1.50, 0.60 < z < 1.50, 0.65 < z < 1.50, 0.70 < z < 1.50, 0.75 < z < 1.50, 0.80 < z < 1.50, 0.85 < z < 1.50, 0.90 < z < 1.50, 0.95 < z < 1.50, 1.00 < z < 1.50, 1.05 < z < 1.50, 1.10 < z < 1.50, 1.15 < z < 1.50, 1.20 < z < 1.50, 1.25 < z < 1.50, 1.30 < z < 1.50, 1.35 < z < 1.50, 1.40 < z < 1.50, or 1.45 < z < 1.50

[0150] In some embodiments, 0.4 < z < 1.0.

[0151] In some embodiments, 0.9 < z < 1.0.

[0152] In some embodiments, y is about, or greater than about: 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50. In some embodiments, y is less than about: 1.50, 1.45, 1.40, 1.35, 1.30, 1.25, 1.20, 1.15, 1.10, 1.05, 1.00, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, 0.00.

[0153] In some embodiments, y may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.00 < y < 1.00, 0.05 < y < 1.00, 0.10 < y < 1.00, 0.15 < y< 1.00, 0.20 < y < 1.00, 0.25 < y < 1.00, 0.30 < y < 1.00, 0.35 < y < 1.00, 0.40 < y < 1.00, 0.45< y < 1.00, 0.50 < y < 1.00, 0.55 < y < 1.00, 0.60 < y < 1.00, 0.65 < y < 1.00, 0.70 < y < 1.00, 0.75 < y < 1.00, 0.80 < y < 1.00, 0.85 < y < 1.00, 0.90 < y < 1.00, 0.95 < y < 1.00.

[0154] In some embodiments, 0.1 < y < 0.6.

[0155] In some embodiments, x is about, or greater than about: 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00. In some embodiments, x is less than about: 1.00, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, 0.00. In some embodiments, x may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.00 < x < 1.00, 0.05 < x < 1.00, 0.10 < x < 1.00, 0.15 < x < 1.00, 0.20 < x < 1.00, 0.25 < x < 1.00, 0.30 < x < 1.00, 0.35 < x < 1.00, 0.40 < x < 1.00, 0.45 < x < 1.00, 0.50 < x < 1.00, 0.55 <X < 1.00, 0.60 < X < 1.00, 0.65 < x < 1.00, 0.70 < x < 1.00, 0.75 < x < 1.00, 0.80 < x < 1.00, 0.85 < x < 1.00, 0.90 < x < 1.00, 0.95 < x < 1.00.

[0156] In some embodiments, w is about, or greater than about: 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00. In some embodiments, w is less than about: 1.00, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.05, 0.00. In some embodiments, w may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.00 < w < 1.00, 0.05 < w < 1.00, 0.10 < w < 1.00, 0.15 < w < 1.00, 0.20 < w < 1.00, 0.25 < w< 1.00, 0.30 < w < 1.00, 0.35 < w < 1.00, 0.40 < w < 1.00, 0.45 < w < 1.00, 0.50 < w < 1.00, 0.55 < w < 1.00, 0.60 < w < 1.00, 0.65 < w < 1.00, 0.70 < w < 1.00, 0.75 < w < 1.00, 0.80 < w< 1.00, 0.85 < w < 1.00, 0.90 < w < 1.00, 0.95 < w < 1.00.

[0157] In some embodiments, y is 0.

[0158] In some embodiments, x is 0.

[0159] In some embodiments, w is 0.

[0160] In some embodiments, x is 0 and w is 0.

[0161] In some embodiments, y is 0, x is 0 and w is 0.

[0162] In some embodiments, w+x+y+z is about, or greater than about: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.00. In some embodiments, c is less than about: 1.00, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, c may be in a range provided by any two or more of the upper and / or lower amounts, for example, 1.00 < c < 1.30, 1.01 < c < 1.30, 1.00 < c < 1.10, 1.00 < c < 1.15, 1.00 < c < 1.20, 1.00 < c < 1.25, 1.00 < c < 1.29, 1.01 < c < 1.10, , 1.01 < c < 1.15, 1.01 < c < 1.20, 1.01 < c < 1.25, 1.01 < c < 1.29, 1.05 < c < 1.10, 1.05 < c < 1.15, 1.05 < c < 1.20, 1.05 < c < 1.25, 1.05 < c < 1.29.

[0163] In some embodiments, w+x+y+z is about, or greater than about: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.00. In some embodiments, c is less than about: 1.00, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07,0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, c may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.01 < w+x+y+z < 1, 0.1 < w+x+y+z < 1, , 0.2 < w+x+y+z < 1, , 0.3 < w+x+y+z < 1, , 0.4 < w+x+y+z < 1, , 0.5 < w+x+y+z< 1, , 0.6 < w+x+y+z < 1, , 0.7 < w+x+y+z < 1, , 0.8 < w+x+y+z < 1, , or 0.9 < w+x+y+z < 1.

[0164] In some embodiments, x+y+z is about, or greater than about: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.00. In some embodiments, c is less than about: 1.00, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, c may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.01 < x+y+z < 1, 0.1 < x+y+z < 1, , 0.2 < x+y+z < 1, , 0.3 < x+y+z < 1, , 0.4 < x+y+z < 1, , 0.5 < x+y+z < 1, , 0.6< x+y+z < 1, , 0.7 < x+y+z < 1, , 0.8 < x+y+z < 1, , or 0.9 < x+y+z < 1.

[0165] In some embodiments, y+z is about, or greater than about: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.00. In some embodiments, c is less than about: 1.00, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01. In some embodiments, c may be in a range provided by any two or more of the upper and / or lower amounts, for example, 0.01 < y+z < 1, 0.1 < y+z < 1, , 0.2 < y+z < 1, , 0.3 < y+z < 1, , 0.4 < y+z < 1, , 0.5 < y+z < 1, , 0.6 < y+z < 1, , 0.7 < y+z < 1, , 0.8 < y+z < 1, , or 0.9 < y+z < 1.Cathode material powder

[0166] In some embodiments, the cathode material is a cathode material powder.

[0167] The particle size of the cathode material powder is measured by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and / or Dynamic Light Scattering (DLS).

[0168] In some embodiments, the cathode material powder has a particle size (in nm) of about, or greater than about: 1, 2, 5, 10, 15, 20, 25, 50, 75, 100, 150, 200, 300, 400, 500, 750, 1000, 1250, 1500, 1750, or 2000. In some embodiments, the cathode material powder has a particle size (in nm) of less than about: 2000, 1750, 1500, 1250, 1000, 750 500, 400, 300, 200, 150, 100, 75, 50, 25, 20, 15, 10, 5, 2 or 1. In some embodiments, the cathode material powder particle size (nm) may be a range provided by any two of these upper and / or lower values, for example between about 1 to about 2000, between about 5 to about 1000, between about 50 to about 500.

[0169] In some embodiments, the cathode material powder particle size (nm) is between about 1 to about 2000.

[0170] In some embodiments, the cathode material powder particle size (nm) is between about 5 to about 1000.

[0171] In some embodiments, the cathode material powder particle size (nm) is between about 50 to about 500.Cathode

[0172] In a second aspect of the present disclosure, there is provided a cathode comprising: a cathode material as described herein; and a current collector.

[0173] In a third aspect of the present disclosure, there is provided a cathode comprising: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0174] In some embodiments, there is provided a cathode comprising: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector. wherein: at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.

[0175] In a fourth aspect of the present disclosure, there is provided a cathode for a rechargeable battery comprising: a cathode material as described herein; and a current collector.

[0176] In some embodiments, there is provided a cathode for a rechargeable battery comprising: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0177] In some embodiments, there is provided a cathode for a rechargeable battery comprising: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector. wherein: at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.

[0178] In some embodiments, the cathode does not contain a binder.

[0179] In some embodiments, the cathode does not contain a conductive agent.

[0180] In some embodiments, the cathode does not contain a binder; and / or the cathode does not contain a conductive agent.

[0181] In some embodiments, the cathode substantially consists of: the cathode material as described herein; and a current collector.

[0182] In another aspect of the present disclosure, there is provided a cathode comprising: the cathode material as described herein; a current collector; a binder; and a conductive agent.

[0183] In some embodiments, the cathode is for a rechargeable battery.Current collector

[0184] The current collector may be any suitable current collector used to prepare electrodes. The current collector may have a morphology and / or properties effective to support the cathode material. In some embodiments, the current collector is selected from a metal, carbon-based, or oxide-based current collector.

[0185] In some embodiments, the current collector is a foil, mesh, foam, or plate current collector.

[0186] In some embodiments, the current collector comprises aluminium, copper, or combinations thereof.

[0187] In some embodiments, the current collector comprises aluminium, FTO, ITO, ferrous alloy, or carbon.

[0188] In some embodiments, the current collector is an aluminium based current collector.

[0189] The current collector may have any suitable thickness. In some embodiments, the thickness of the current collector (in pm) is about, or greater than about: 10, 20, 50, 70, 100, 120, 150, 200, 250, 300, 350, 400, 500, 600, 800 or 1000. The thickness of the current collector (in pm) is less than about: 1000, 800, 600, 500, 400, 350, 300, 250, 200, 150, 120, 100, 70, 50, 20 or 10. In some embodiments, the thickness of the current collector (in pm) may be a rangeprovided by any two of these upper and / or lower values, for example, between about 10 pm to about 1000 pm, or between about 50 to about 200.Cathode material film

[0190] In some embodiments, the cathode material is a film on one or more surfaces of the current collector.

[0191] In some embodiments, the cathode comprises a film on one or more surfaces of the current collector, wherein the film comprises the cathode material as described herein.

[0192] The thickness of the film is measured by Transmission Electron Microscopy (TEM), and / or Scanning Electron Microscopy (SEM) imaging.

[0193] In some embodiments, the thickness of the film (in pm) is about, or greater than about:I, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 300, 400, or 500. In some embodiments, the thickness of the film (in pm) is less than about 500, 400, 300, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 5, 4, 3, 2, or 1. In some embodiments, the thickness of the film (in pm) may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 1 and about 500, or between about 100 to about 300.

[0194] In some embodiments, the thickness of the film (pm) is between about 1 to about 500.

[0195] In some embodiments, the thickness of the film (pm) is between about 100 to about 300.

[0196] In some embodiments, the thickness of the film (pm) is about 200.

[0197] In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is about, or greater than about: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75. In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is less than about: 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12,I I, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.1. In some embodiments,the mass loading of the cathode material on the current collector (mg / cm2) may be in an amount range provided by any two of these upper and / or lower values, for example between about 0.1 and about 75, or between about 1 and about 50, or between about 10 to about 40.

[0198] In some embodiments, the amount of cathode material in the cathode (% w / w) based on the total weight of the cathode is about, or greater than about: 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99, 99.5, 99.9, 99.95, 99.99, 99.995, or 99.999. In some embodiments, the amount of cathode material in the cathode (% w / w) based on the total weight of the cathode is less than about: 99.999, 99.995, 99.99, 99.95, 99.9, 99.5, 99, 98, 97, 96, 95, 94, 93, 92, 91, or 90, 85, 80, or 75. The amount of cathode material in the cathode (% w / w) based on the total weight of the cathode may be in a range provided by any two of these upper and / or lower values, for example between about 75 and about 99.999, between about 95 and about 99.99, or between about 95 and about 99.9.

[0199] In some embodiments, the cathode comprises between about 70 to about 95 (% w / w) of the cathode material based on the total weight of the cathode.

[0200] In some embodiments, the thickness of the cathode (in pm) is about, or greater than about: 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 300, 400, 500, 600, 700, 800, 900, or 1000. In some embodiments, the thickness of the cathode (in pm) is less than about 1000, 900, 800, 700, 600, 500, 400, 300, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, or 5. In some embodiments, the thickness of the cathode (in pm) may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 5 and about 1000, or between about 200 to about 600. In some embodiments, the thickness of the cathode (in pm) is about 400.Electrochemical cell

[0201] In a fifth aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode material as described herein.

[0202] In some embodiments, there is provided an electrochemical cell comprising a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0203] In some embodiments, there is provided an electrochemical cell comprising a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, wherein: at least a portion of the layered transition metal oxide is isomorphous with birnessite, and the layered transition metal oxide is substantially anhydrous.

[0204] In a sixth aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode material powder as described herein.

[0205] In a seventh aspect of the present disclosure, there is provided an electrochemical cell comprising the cathode as described herein.

[0206] In some embodiments, there is provided an electrochemical cell comprising a cathode, wherein the cathode comprises: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

[0207] In some embodiments, there is provided an electrochemical cell comprising a cathode, wherein the cathode comprises: a cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations;(b) one or more transition metal cations; and a current collector, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite; and the layered transition metal oxide is substantially anhydrous.Use

[0208] In an eighth aspect of the present disclosure, there is provided the use of the cathode material as described herein in the manufacture of a cathode.

[0209] In a ninth aspect of the present disclosure, there is provided the use of the cathode material as described herein in the manufacture of an electrochemical cell.

[0210] In some embodiments, there is provided the use of the cathode material as described herein in the manufacture of a cathode and / or in the manufacture of an electrochemical cell.

[0211] In some embodiments, there is provided the use of the cathode material powder as described herein in the manufacture of a cathode and / or in the manufacture of an electrochemical cell.

[0212] In an tenth aspect of the present disclosure, there is provided the use of the cathode as described in the manufacture of an electrochemical cell.EXAMPLE EMBODIMENTS

[0213] The present disclosure may be described by one or more of the following example embodiments:1. A cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, and wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.2. The cathode material according to example embodiment 1, wherein the stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is greater than about 1.00.3. The cathode material of any one of the preceding example embodiments, wherein the layered transition metal oxide is of formula (I):CcM1zM2yM3xM4wO2, wherein:C is the one or more alkali metal cations;1.00 < c < 1.30;M1, M2, M3, and M4are the one or more transition metal cations;0 < z < 1.0;0 < y < 1.0;0 < x < 1.0;0 < w < 1.0; and0.7 < z+y+x+w < 1.0.4. The cathode material according to example embodiment 3, wherein 0.4 < z < 1.0.5. The cathode material according to example embodiment 3 or example embodiment 4, wherein 0.1 < y < 0.6.6. The cathode material according to any one of example embodiments 3 to 5, wherein M1is a cation of Mn.7. The cathode material according to any preceding example embodiment, wherein a stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is between about 1.01 to about 1.25.8. The cathode material according to any preceding example embodiment, wherein the layered transition metal oxide the layered transition metal oxide is substantially anhydrous.9. The cathode material according to any preceding example embodiment, wherein the one or more transition metal cations are of elements selected from Mn, Fe, Ni, V, Ti, and Mo.10. The cathode material according to any preceding example embodiment, wherein the one or more transition metal cations are of elements selected from Mn, Fe, Ni, and Mo.11. The cathode material according to any preceding example embodiment, wherein the layered transition metal oxide consists of two transition metal elements.12. The cathode material according to example embodiment 11, wherein: the two elements are Mn and Fe; or the two elements are Mn and Mo; or the two elements are Mn and Ni.13. The cathode material according to any preceding example embodiment, wherein the layered transition metal oxide consists of three transition metal elements.14. The cathode material according to example embodiment 13, wherein: the three elements are Mn, Fe and Mo; or the three elements are Mn, Fe and Ni; or the three elements are Mn, Mo and Ni.15. The cathode material according to any preceding example embodiment, wherein the one or more alkali metal cations is Na+.16. The cathode material according to any one of example embodiments 1 to 14, wherein the layered transition metal oxide comprises two alkali metal cations, optionally wherein the two alkali metal cations are Li+and Na+.17. The cathode material according to any preceding example embodiment, wherein at least 50 %w / w of the cathode material is the layered transition metal oxide.18. The cathode material according to any preceding example embodiment, wherein at least 20 %w / w of the layered transition metal oxide is isomorphous with birnessite.19. The cathode material according to any preceding example embodiment, wherein: at least 90 %w / w of the cathode material is the layered transition metal oxide; and / or at least 90 %w / w of the layered transition metal oxide is isomorphous with birnessite.20. A cathode comprising: the cathode material of any one of example embodiments 1 to 19; and a current collector.21. The cathode according to 20, wherein:the cathode does not contain a binder; and / or the cathode does not contain a conductive agent.22. The cathode according to example embodiment 20 or example embodiment 21, wherein the cathode substantially consists of: the cathode material according to any one of example embodiments 1 to 19; and a current collector.23. A cathode comprising: the cathode material according to any one of example embodiments 1 to 19; a current collector; a binder; and a conductive agent.24. The cathode according to any one of example embodiments 19 to 23, wherein the current collector is selected from current collector comprises aluminium, ferrous alloy, or carbon, optionally wherein the current collector is an aluminium based current collector.25. The cathode according to any one of example embodiments 19 to 24, wherein the cathode comprises a film on one or more surfaces of the current collector and the film comprises the cathode material.26. The cathode according to example embodiment 25, wherein the thickness of the film (in pm) is between about 1 to about 500, optionally wherein the thickness of the film (in pm) is between about 100 to about 300.27. An electrochemical cell comprising the cathode according to any one of example embodiments 19 to 25.28. Use of the cathode material according to any one of example embodiments 1 to 19 in the manufacture of a cathode and / or in the manufacture of an electrochemical cell.29. Use of the cathode according to any one of example embodiments 20 to 26 in the manufacture of an electrochemical cell.EXAMPLESPotential cathode materials

[0214] Table 1 shows layered transition metal oxides within the scope of the present disclosure.Table 1 : Layered transition metal oxides

[0215] It will be appreciated where M1and M2have different oxidation states M1and M2may be the same transition metal element or M1and M2may be different transition metal elements. It will be appreciated where M1and M3have different oxidation states M1and M3may be the same transition metal element or M1and M3may be different transition metal elements. It will be appreciated where M2and M3have different oxidation states M2and M3may be the same transition metal element or M2and M3may be different transition metal elements.Process conditions and cathode materials obtained

[0216] Table 2 shows the experimental conditions for fabrication of single, binary, and ternary transition metal oxides of the present disclosure.Table 2: Process conditions and cathode materials obtainedPourbaix diagrams

[0217] Pourbaix diagrams may be used to identify relevant process condition changes that can facilitate deposition of the cathode material. Pourbaix diagrams may include: the ordinate is E or the applied electric bias; the abscissa is the pH; the conditions for the stability of the soluble salts (aq) and solid precipitates (5) are shown. the lines between the stability regions represent 50 / 50 atomic percents of the two relevant phases; and the conditions for which water is stable are shown, where going outside of these result in the generation of H2 or O2.

[0218] Pourbaix diagrams show the (a) relevant TMOs that must be prepared and (b) the experimental conditions that must be applied to fabricate the TMOs.

[0219] Figure 1 illustrates a Pourbaix diagram generated for the ternary Na-Mn-H20 system. The Pourbaix diagram highlights the pathway (red solid line) as the only pathway to obtain the stoichiometric NaMnO2. The red solid line pathway yields Na intercalation capacity >1 (z.e., Nai.iMnO2), while the Pourbaix diagram is limited to stoichiometric NaMnO2. The probable reason for this is suggested by the design of the Pourbaix diagram, where Mn4+of MnO(OH) is to the left of the NaMnO2 stability region, Mn3+is present in the NaMnO2 stability region, and Mn2+of MnO ‘ is to the right of the NaMnCh stability region. Consequently, it is likely that the NaMnCb stability region effectively consists of a gradient of Mn redox conditions, wherethe presence of H2 gas causes progressive reduction of the Mn of NaMnCb. Consequently, it is likely that pH values >14.5 will result in progressively higher Na+intercalation capacities (x > 1.1).

[0220] In contrast, Path 1 results in the preliminary precipitation of MnO(OH), which then is retained as an undesirable secondary phase. Similarly, Path 2 results in the preliminary precipitation of MnCb, which can be intercalated ex situ with Nat The inventors have discovered that, compositions on the left side of the NaMnCb stability region require exiting the water-stability region while compositions on the right side of the NaMnCb stability region (thus avoiding H2 generation) result in phase assemblages with only slightly more than 50 at% NaMnCb, which is intercalated in situ with Na+. The in situ intercalation capacity of Na+is significantly greater than the ex situ intercalation capacity of Na+.

[0221] The Pourbaix diagram for a quaternary variant with two TMOs is shown in Figure 2. The relevant quaternary phase that was calculated to exhibit the lowest Gibbs free energy and hence would be the most stable was NaJ^Feo^Mno^C^. In effect, this calculation sets a starting Na+intercalation capacity of x = 1.2; with potentially significant further increase in x through reduction by H2 gas, with charge compensation from increasing Mn4+reduction to Mn3+ / Mn2+. The same effect could be achieved by increasing the initial Fe^ level. Thus, the pathway was strategised by manually increasing the pH, applying a negative bias, holding the bias to allow H2 gas to increase the pH even higher, and increasing the negative bias to enter the (vertical) centre of the Na1.2Feo.4Mno.5O2 stability region.General procedure

[0222] A general procedure for the process of deposition the cathode material deposits on the current collector and / or forming an electrode comprising the cathode material is as follows:• obtaining an aqueous solution comprising at least one alkali metal cation and a soluble ion of at least one transition metal which is obtained by o dissolving at least one alkali metal in an aqueous solution, o dissolving at least one transition metal salt the aqueous solution, o the pH pf the aqueous solution may be any suitable pH to ensure solubility of the at least one alkali metal cation and the ion of the at least one transition metal, o it will be understood by the person skilled in the art that the ion of the at least one transition metal may be a cation, an anion, and combinations thereof,o it will be understood by the person skilled in the art that the order of addition of the at least one alkali metal salt and the at least one transition metal salt is not particularly important to the process;• immersing at least a portion of the current collector and a counter electrode in the aqueous solution,• changing the conditions of the aqueous solution by: o adding a base to increase the pH of the aqueous solution, particularly in the vicinity of the current collector, and / or o applying a voltage between the current collector and the counter electrode, o it will be understood by the person skilled in the art that the addition of the base may be performed in one or more stages, such that the pH is increased in one or more stages, o it will be understood by the person skilled in the art that the voltage applied may be changed throughout the process such that different voltages are applied at the same and / or different pH values, o it will be understood that the addition of a base may be performed in conjunction with the application of a voltage such that the pH of the aqueous solution is changed while a voltage is applied between the current collector and the counter electrode.

[0223] By systematically changing the pH of the solution and the applied voltage such that along the reaction pathway only the desired final cathode material is a stable solid throughout the process, with the initial salts selected and all intermediaries along the path being stable as aqueous salts, the inventors have surprisingly discovered that it is possible to obtain high purity cathode materials with elevated levels of intercalated alkali metals, particularly sodium relative to processes currently known in the art.

[0224] Advantageously, compared to conventional direct deposition strategies such as molten salt process, in which the alkali cation to transition metal cation ratio generally exceeds 300, making the system super corrosive and limited to be scaled up, in the process of forming the cathodes and cathode material as described herein, the alkali cation to transition metal cation ratio can be as low as 1, preferably between 1 to 100 or between 10 and 60, which is safe, green, and scalable. To provide the required ration of alkali cation to transition metal cation ratio, for example, the concentration (in M) of the cations of alkali metals in the aqueous solution isbetween about 0.01 to about 60, between about 5 to about 60, or between about 10 to about 20 and the concentration (in M) of the one or more transition metals cations in the aqueous solution can be between about 0.01 and about 30.

[0225] Further, the process of forming the cathodes and cathode material as described herein, the inventors have discovered a cost-effective electrodeposition process which may require a relatively low power input and may allow for at least a portion of the precursor materials to be recycled reducing waste during cathode and cathode material fabrication. For example, the voltage applied to the current collector or substrate in the deposition stage is between about - 0.1 V to about -4.0 V relative to a standard hydrogen electrode, or between about -0.1 V to about -2.5 V relative to a standard hydrogen electrode. The voltage may be applied such that the current to the current collector or substrate per unit area (mA / cm2) is between about 0.01 to about 50.Unary system

[0226] Sodium salt was dissolved in water to provide and aqueous solution with a sodium cation concentration of between 0.01 M up to the solubility limit of the sodium salt (typically 0.5 M). Mn salt was dissolved in said aqueous solution to provide and aqueous solution with a manganese cation concentration of between 0.01 M up to the solubility limit of the manganese salt (typically 0.125 M). The pH of the aqueous solution was between 7-12 (typically ~ 11.5). A current collector was washed in a 1 : 1 v / v mixture of ethanol, followed by washing in water, followed by soaking in the above aqueous solution for > 1 h (typically 24 hours). This is done to ensure the current collector is fully wetted by the aqueous solution to enable homogenous deposition on the entire current collector surface, which is essential for achieving high mass loading. The washed current collector was connected to a counter electrode and immersed in the aqueous solution. Sodium hydroxide was added to the solution to change the pH to between 12-14 (typically 13.1). Subsequently a voltage of-l.3-2.5 vs SHE (typically 1.4 V) was applied at the current collector (working electrode) such that NaxMny02 was deposited on the current collector. Vigorous stirring of the aqueous stirring was maintained during the application of the voltage. Hydrogen was observed to evolve at the current collector during deposition. The voltage was applied for the time required to pass between 1 and 40 mAhcm'2(typically 10 mAhcm'2) of the current collector. The magnitude of the applied capacity is proportional to the deposition mass loading, such that ~1 mAhcm'2will give 1 mgcm'2of the deposition. Following the deposition, the current collector and deposited NaxMny02 was washed with water, dried,and annealed by maintaining a temperature between 100 and 400 °C for 1 to 20 hours, under a nitrogen, air, argon, or vacuum atmosphere.Binary system

[0227] All of the above steps for the unary system were applied, with the addition of the following step. A second transition metal salt e.g. an iron salt, was dissolved in the aqueous solution, following the addition of the manganese salt, to achieve a concentration of said transition metal of between 0.01 up to the solubility limit of the transition metal salt. Typically, the concentration of the second metal in the solution is relative to the concentration of the manganese, to achieve a specific ratio of Mn:TM, e.g., 98:2. In the case of a binary system containing Mn and Fe, an Mn:Fe ratio of up to 91 :9 has been achieved, as indicated by ICP-MS results.Ternary system

[0228] All of the above steps for the binary system were applied, with the addition of the following step. A third transition metal salt e.g. a vanadium salt, was dissolved in the aqueous solution, following the addition of the manganese salt, to achieve a concentration of said transition metal of between 0.01 up to the solubility limit of the transition metal salt. Typically, the concentration of the third metal in the solution is relative to the concentration of the manganese, to achieve a specific ratio of Mn:Fe:Mo, e.g., 99.200:0.199:0.681.Performance characteristics of cathode material

[0229] Figure 11 shows the electrochemical performance of coin half-cells incorporating the Nao.37Mn02 and Na1.1Mm.xO2 cathodes fabricated using the process described herein. These results represent the first time that Na-rich TMO cathodes have been deposited directly on fluoride-tin oxide, carbon foam, and aluminium foil also, see Figure 3. Despite the thickness of the films (-100 pm), they remain flexible.

[0230] The reason for this is the unique ability of electrochemical deposition to form Na-rich foliate nanostructures of units of <4 pm diameter, each of which is comprised of 2D nanosheet arrays of sheet thickness <10 nm, as shown in Figure 4. These images show aspects of the structural, morphological, and chemical characteristics of the cathode materials produced by the method described herein.

[0231] When cycled in the range 2.0-4.3 V vs Na / Na+, NatuvMnCh produced typical charge and discharge capacities of 150 and 145 mAh g'1, respectively. However, when the technique was adapted to form Na1.1Mn1.xO2 and cycled over the same range, there were significant improvements in the charge and discharge capacities to 212 and 189 mAh g'1, respectively, which are significantly increased charge and discharge capacities.

[0232] Figure 6 shows the galvanostatic diagram showing charge / discharge capacities of Na- rich cathodes (Nai.iMnO2) in a half-coin cell configuration with Na metal as anode at 0.1 C charge / discharge rates (10 hours charge and 10 hours discharge times).

[0233] Figure 11 shows the first-cycle galvanostatic charge / discharge capacities of the single TMO (NaojvMnCh) and binary TMO (Na1.2Feo.4Mno.5O2) at 0.1 C rates (10 hours charge and 10 hours discharge times) which again show significantly increased charge and discharge capacities.Crystal structure stability comparison

[0234] NaxMnO2, where x > 1.0 and a (001) interlayer lattice spacing of ~7 A without interlayer H2O have been synthesised for the first time (although a tentative value of x = 1.3 has been achieved). Previous disclosures of this compound always have x < 1 and the (001) interlayer lattice spacing of <~7 A is occupied by water such that the actual composition and structure is NaxMnCh- HHLO (x < 1). The experimental data of cathode materials obtained from the process described herein confirm that the NaxMnCh (where x > 1.0) exhibits a (001) interlayer lattice spacing of ~7 A but without any H2O, which potentially allows for the increased Na content. In addition, the inventors opine that at least a portion of the excess Na may be located in the MnCb layers which may explain the near-constancy of the layer thickness upon charge / discharge. This has been shown to apply to structures containing both one and two TMs.

[0235] Figure 14 shows the X-ray diffraction patterns for experimental high-Na Nai.iMnCh after a single charge / discharge cycle (top) and reference pattern for NaxMnCh I’ / MLO, where 0 < x < 1 (bottom); the key observation is that the lattice spacings (including the (001) plane spacing of ~7 A) of the structure shifts only to slightly smaller values (z.e., lattice expansion) after a charge / discharge cycle (discharging of the cathode normally results in expansion owing to the greater repulsion of the oxygen ions upon removal of the Na ions), without change to thepattern (z.e., without structural change), which indicates that the remaining intercalated Na ions are structurally ordered, thereby retaining the structure during cycling, thus suggesting high capacity retention, cycling stability, and long lifetime.

[0236] In contrast, X-ray diffraction patterns for experimental low-Na NatuvMnCh after a single charge / discharge cycle (top) and reference pattern for P2-type monoclinic NaxMnCh, where 0 < x < 1 (bottom); the key observation is that the (001) plane spacing of the as- synthesised Nao.37Mn02, which is ~7.0 A (Figure 14) is reduced to 5.3 A after a single charge / discharge cycle and the XRD pattern becomes effectively identical with the known P2- type monoclinic NaxMnCh structure.

[0237] XRD patterns of the Fe-containing binary TMO synthesised according to the relevant high-Na salt indicated on the Pourbaix diagram (Na1.2Feo.4Mno.5O2 (black line)) and Mo- containing TMO NaxMoo.1Mno.9O2 (red line); the key observation is that the pattern is effectively identical to that of Nai.iMnOi, thus indicating that the mechanism for the formation of high-Na NaxMnO2 applies to both cases of a single TM (Mn) and two TMs (Mn-Fe and Mn-Mo).

[0238] Figure 26 shows galvanostatic charge / discharge curves of Nax / Mn]^ Mn^+)Cb electrodes at different mass loadings synthesised by the process described herein. The data indicates that the performance remains relatively constant despite different mass loadings. This confirms that the mass loading can be increased without deteriorating the capacity.Structural Disorder

[0239] The inventors have also observed that, in some circumstances, the material undergoes structural distortion such that the Mn-O-Na bond between the structural layer (Mn-0) and the interlayer (Na) alters from the typical 120° to 180°. This structural disorder affects the structural dynamics during charge and discharge, resulting in alteration of the electrochemical behaviour.

[0240] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS1. A cathode material comprising a layered transition metal oxide, wherein the layered transition metal oxide comprises:(a) one or more alkali metal cations; and(b) one or more transition metal cations, and wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite.

2. The cathode material according to claim 1, wherein the stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is greater than about 1.00.

3. The cathode material of any one of the preceding claims, wherein the layered transition metal oxide is of formula (I):CcM1zM2yM3xM4wO2, wherein:C is the one or more alkali metal cations;1.00 < c < 1.30;M1, M2, M3, and M4are the one or more transition metal cations;0 < z < 1.0;0 < y < 1.0;0 < x < 1.0;0 < w < 1.0; and0.7 < z+y+x+w < 1.0.

4. The cathode material according to claim 3, wherein 0.4 < z < 1.0.

5. The cathode material according to claim 3 or claim 4, wherein 0.1 < y < 0.6.

6. The cathode material according to any one of claims 3 to 5, wherein M1is a cation ofMn.

7. The cathode material according to any preceding claim, wherein a stoichiometric ratio of the alkali metal cations to the transition metal cations in the layered transition metal oxide is between about 1.01 to about 1.25.

8. The cathode material according to any preceding claim, wherein the layered transition metal oxide the layered transition metal oxide is substantially anhydrous.

9. The cathode material according to any preceding claim, wherein the one or more transition metal cations are of elements selected from Mn, Fe, Ni, V, Ti, and Mo.

10. The cathode material according to any preceding claim, wherein the one or more transition metal cations are of elements selected from Mn, Fe, Ni, and Mo.

11. The cathode material according to any preceding claim, wherein the layered transition metal oxide consists of two transition metal elements.

12. The cathode material according to claim 11, wherein: the two elements are Mn and Fe; or the two elements are Mn and Mo; or the two elements are Mn and Ni.

13. The cathode material according to any preceding claim, wherein the layered transition metal oxide consists of three transition metal elements.

14. The cathode material according to claim 13, wherein: the three elements are Mn, Fe and Mo; or the three elements are Mn, Fe and Ni; or the three elements are Mn, Mo and Ni.

15. The cathode material according to any preceding claim, wherein the one or more alkali metal cations is Na+.

16. The cathode material according to any one of claims 1 to 14, wherein the layered transition metal oxide comprises two alkali metal cations, optionally wherein the two alkali metal cations are Li+and Na+.

17. The cathode material according to any preceding claim, wherein at least 50 %w / w of the cathode material is the layered transition metal oxide.

18. The cathode material according to any preceding claim, wherein at least 20 %w / w of the layered transition metal oxide is isomorphous with birnessite.

19. The cathode material according to any preceding claim, wherein: at least 90 %w / w of the cathode material is the layered transition metal oxide; and / or at least 90 %w / w of the layered transition metal oxide is isomorphous with birnessite.

20. A cathode comprising: the cathode material of any one of claims 1 to 19; and a current collector.

21. The cathode according to 20, wherein: the cathode does not contain a binder; and / or the cathode does not contain a conductive agent.

22. The cathode according to claim 20 or claim 21, wherein the cathode substantially consists of: the cathode material according to any one of claims 1 to 19; and a current collector.

23. A cathode comprising: the cathode material according to any one of claims 1 to 19; a current collector; a binder; and a conductive agent.

24. The cathode according to any one of claims 19 to 23, wherein the current collector is selected from current collector comprises aluminium, ferrous alloy, or carbon, optionally wherein the current collector is an aluminium based current collector.

25. The cathode according to any one of claims 19 to 24, wherein the cathode comprises a film on one or more surfaces of the current collector and the film comprises the cathode material.

26. The cathode according to claim 25, wherein the thickness of the film (in pm) is between about 1 to about 500, optionally wherein the thickness of the film (in pm) is between about 100 to about 300.

27. An electrochemical cell comprising the cathode according to any one of claims 19 to 25.

28. Use of the cathode material according to any one of claims 1 to 19 in the manufacture of a cathode and / or in the manufacture of an electrochemical cell.

29. Use of the cathode according to any one of claims 20 to 26 in the manufacture of an electrochemical cell.

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