Methods of manufacture

Abstract

The present disclose relates to processes for producing layered transition metal oxide materials and electrodes comprising the same. In particular, the present application relates to processes for producing layered transition metal oxide materials comprising alkali metals and electrodes comprising the same.

Description

METHODS OF MANUFACTURE CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority from Australian Provisional Patent Application No 2024901585 filed on 28 May 2024, 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 μm 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 LixTMO2 and NaxTMO2 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 ofthese 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] In part, the present disclosure provides a process for the electrodeposition of a cathode material on a substrate. In some embodiments, the process comprises providing an aqueous solution comprising one or more salts comprising a cation of an alkali metal and one or more salts comprising a transition metal cation and changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate. In some embodiments, the cathode material deposited on the substrate may be a metal oxide. In some embodiments, the cathode material deposited on the substrate may be a metal oxide incorporating the cations of the alkali metal. In some embodiments, the cathode material deposited on the substrate may be a transition metal oxide. In some embodiments, the cathode material deposited on the substrate may be a transition metal oxide incorporating the cations of the alkali metal. In some embodiments, the cathode material deposited on the substrate may be a layered transition metal oxide. In some embodiments, the cathode material deposited on the substrate may be a layered transition metal oxide incorporating the cations of the alkali metal.

[0010] In first aspect of the present disclosure, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising cations of alkali metals, one or more salts comprising transition metal cations of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein the cathode material is a layered transition metal oxide incorporating the cations of the alkali metal.

[0011] In second aspect of the present disclosure, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising:one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: hydrogen is evolved at and / or near the current collector in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0012] In part, the present disclosure provides a process for the electrodeposition of a cathode material on a substrate. In some embodiments, the process comprises providing an aqueous solution comprising one or more salts comprising a cation of an alkali metal and one or more salts comprising a transition metal cation and changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate. The cathode material deposited on the substrate may be a layered transition metal oxide incorporating the cations of the alkali metal.

[0013] In third aspect of the present disclosure, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0014] In fourth aspect of the present disclosure, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising:one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein: hydrogen is evolved at and / or near the substrate in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0015] Various aspects and embodiments of the present disclosure may advantageously provide for one or more of the following: - the direct electrochemical deposition of cathode material onto a substrate and / or current collector using aqueous solutions without the need for binder and / or conductive agent; - room-temperature processing without the need for high-temperature annealing; - low-power fabrication; - simple and rapid processing technique of thin- to thick-layer cathodes involving only a single stage of electrodeposition; - cost-effectiveness from the preceding as well as unlimited areal deposition capacity owing the nature of electrodeposition; - high-yield process from scalability deriving from dimensional flexibility of electrodeposition; and / or - combined energy storage (battery cathode) and energy transformation (hydrogen generation as a by-product of the process).

[0016] Cathodes or cathodes comprising the cathode material obtained from the process described herein may offer improvements in terms of capacity, energy density, power density, and / or cycling stability. The inventors have surprisingly discovered that, in some aspects or embodiments, by using the process described herein it may be possible to produce an alkali metal cation-rich cathode layered transition metal oxide material with reduced water content. Beneficially, higher alkali metal concentration can increase the number of available charge carriers, which can lead to improved capacity and higher energy density, which is a key performance metric for next-generation batteries. Further, the inventors have surprisinglydiscovered that, in some aspects or embodiments, using the process described herein it may be possible to produce a layered transition metal oxide material with reduced water content thereby reducing the detrimental impact that the presence of water has on cathode materials during electrochemical operation.

[0017] Furthermore, in some aspects or embodiments described herein, the process described herein provides for a direct electrodeposition which can be undertaken directly on a wide variety of current collector and / or substrates. Non-limiting examples may include nickel foam, aluminium foil, carbon foam. In addition, in some aspects or embodiments described herein, the cathode film thickness may be controlled. This may provide for improvements in electrode conductivity, capacity, gravimetric energy density, and / or cycling stability (Coulombic efficiency).

[0018] In some aspects or embodiments described herein, due to the nature of the electrodeposition. the process may provide for good scalability and / or may be applied using substrates and / or current collectors of a wide variety of sizes, for example in terms of surface area, allowing the production of cathodes for a range of applications.

[0019] In addition, the inventors have discovered that by the stepwise or continuous alteration of the voltage applied to the current collector / substrate and / or the pH of the aqueous solution it may be possible to deposit desired layered transition metal oxide without the precipitation of undesired secondary phases, thereby potentially improving the quality of the cathode material. Thus, in some aspects or embodiments as described herein, the process described herein may provide for effective control over the transition metal oxide stoichiometry and / or mineralogy.

[0020] Through the process 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. BRIEF DESCRIPTION OF DRAWINGS

[0021] 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-H2O Pourbaix diagram, highlighting pH-voltage pathway as a pathway to obtain the stoichiometric NaMnO2.Figure 2: Calculated quaternary Mn-Fe-Na-H2O Pourbaix diagram, highlighting pH- voltage pathway as a pathway to achieve Na-rich Na1.2Fe2+0.4Mn4+0.5O2. 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 of 4 powder of 2D nanosheet architecture.of electrochemical performances of sodium-ion battery cathode materials, operating voltages, capacities, and energy densities (O3 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 (Na1.1MnO2) 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 (Na1.1MnO2) 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 (Na1.1MnO2) 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 Na1.1MnO2; red line shows result for Na0.37MnO2). Figure 10: Aberration-corrected (AC) and high-resolution (HR) transmission electron microscopy (TEM) images of the layered structure of nanocrystalline NaxMnO2 cathode material deposited on a current collector. Figure 11: First-cycle galvanostatic charge / discharge capacities of the single TMO (Na0.37MnO2) and binary TMO (Na1.2Fe0.4Mn0.5O2) 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 (Na1.2Fe0.4Mn0.5O2) 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 NaxMo0.1Mn0.9O2at 0.1 C (10 hours charge and 10 hours discharge times). Figure 14: left: ICP-MS and EDS results showing concentrations of Na in Na0.37MnO2 and Na1.1MnO2 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 Na1.1MnO2 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 Na1+xFexMn1-xO2 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 Na1.1MnO2after a single charge / discharge cycle (top) and reference pattern for NaxMnO2^1½H2O, where 0 ≤ x ≤ 1 (bottom). Figure 19: X-ray diffraction patterns for experimental low-Na Na0.37MnO2after a single charge / discharge cycle (top) and reference pattern for P2-type monoclinic NaxMnO2, where 0 ≤ x ≤ 1 (bottom). Figure 20: Fourier transform infrared photospectrometry (FTIR) spectra for P2-type monoclinic Na0.37MnO2 and Na1.1MnO2; the key observation is the absence of the large and broad H2O stretching vibration for H-O at ~3000 nm, confirming the absence of water in both experimental structures Figure 21: XRD patterns of the Fe-containing binary TMO synthesised according to the relevant high-Na salt indicated on the Pourbaix diagram (Na1.2Fe0.4Mn0.5O2 (black line)) and Mo-containing TMO NaxMo0.1Mn0.9O2 (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 Na1.1MnO2 deposited on a carbon foam. The negligible mass loss inthe TGA curve confirms the minimal structural water loss of ~0.7 wt% = 6.33 10mol. Figure 23: Solid-state nuclear magnetic resonance (ssNMR) results of low-Na Na0.37MnO2and high-Na Na1.1MnO2in different charge state (OCV = open circuit voltage; C4.2 = charge up to 4.2 V vs 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+; D1.5 = 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 NaxMnyFexMozO2batteries. Figure 26: Nax(Mn41+-xMn3x+)O2electrodes: Galvanostatic charge / discharge curves of low (Left: 2-4 mg^cm2) and high (Right: 16-20 mg^cm-2) mass loadings. DESCRIPTION OF EMBODIMENTS

[0022] The present disclosure describes the following various non-limiting embodiments, processes, methods compositions and / or articles. General Terms

[0023] 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.

[0024] 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.

[0025] All publications discussed and / or referenced herein are incorporated herein in their entirety.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] As used herein, the term “about”, unless stated to the contrary, typically refers to + / - 10%, for example + / - 5%, of the designated value.

[0032] 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.

[0033] 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 sub- ranges 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 specifically disclosed 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.

[0034] 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.

[0035] 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%.

[0036] Herein “weight %” may be abbreviated to “wt%” or “%w / w”.

[0037] 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. Processes Cathode formation

[0038] In a first aspect of the present disclosure, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising cations of alkali metals,one or more salts comprising transition metal cations of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein the cathode material is a layered transition metal oxide incorporating the cations of the alkali metal.

[0039] In some embodiments, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising cations of alkali metals, one or more salts comprising transition metal cations of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: the cathode material is a layered transition metal oxide incorporating the cations of the alkali metal; and the changing the pH and / or the changing the voltage defines a pH-voltage pathway between the first stage and the deposition stage.

[0040] In a second aspect of the present disclosure, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: hydrogen is evolved at and / or near the current collector in the deposition stage; andthe cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0041] In some embodiments, there is provided a process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising cations of alkali metals, one or more salts comprising transition metal cations of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: hydrogen is evolved at and / or near the current collector in the deposition stage; the cathode material is a layered transition metal oxide incorporating the cations of the alkali metal; and the changing the pH and / or the changing the voltage defines a pH-voltage pathway between the first stage and the deposition stage. Cathode material deposition

[0042] In a third aspect of the present disclosure, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0043] In some embodiments, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal,one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein: the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal; and the changing the pH and / or the changing the voltage defines a pH-voltage pathway between the first stage and the deposition stage.

[0044] In a fourth aspect of the present disclosure, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein: hydrogen is evolved at and / or near the or substrate in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

[0045] In some embodiments, there is provided a process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein:hydrogen is evolved at and / or near the substrate in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal; and the changing the pH and / or the changing the voltage defines a pH-voltage pathway between the first stage and the deposition stage.

[0046] The various embodiments described herein may apply to the first, second, third, and / or fourth aspects of the present disclosure. Hydrogen evolution

[0047] In some embodiments, the pH and voltage at the deposition stage is outside the water stability range. In some embodiments, at the deposition stage water is unstable.

[0048] In some embodiments, hydrogen is evolved at and / or near the current collector in the deposition stage.

[0049] In some embodiments, hydrogen is evolved at and / or near the current collector from the aqueous solution in the deposition stage.

[0050] In some embodiments, hydrogen is evolved at and / or near the current collector or substrate from the aqueous solution in the deposition stage.

[0051] In some embodiments, hydrogen is evolved at and / or near the substrate in the deposition stage.

[0052] In some embodiments, hydrogen is evolved at and / or near the substrate from the aqueous solution in the deposition stage.

[0053] It is generally considered that the generation of one or more gases at, or around, the site of electrodeposition is disruptive to the deposition of material on a substrate or current collector. However, the inventors of the present application have surprisingly discovered that performing the electrodeposition at conditions where water is unstable, such that hydrogen gas is generated, provides an advantage wherein the hydrogen gas can act as a reducing agent and may contribute to an increase in alkali metal cation incorporation into a deposited layered transition metal oxide.

[0054] Further, the inventors have discovered that locally generated hydrogen can also potentially facilitate the removal of water molecules from the interlayer spacing of the deposited material. Thus, by operating outside the water-stability region, the inventors have surprisingly discovered that it is possible to produce an alkali metal cation-rich cathode layered transitionmetal oxide material with reduced water content. Water is known to be detrimental to electrochemical performance and, for example, can introduce volatility, facilitate undesirable side reactions with electrolytes, and / or compromise cycling stability. Thus, the inventors have discovered that hydrogen evolution at or near the substrate / current collector can potentially reduce the water content of the deposited cathode material obtained from a process described herein and potentially reduce the detrimental impact that the presence of water has on cathode materials during electrochemical operation. Deposition

[0055] In some embodiments, the cathode material may be deposited on one side of the current collector. In some embodiments, the cathode material may be deposited on both sides of the current collector.

[0056] In some embodiments, the process involves a single stage of electrodeposition of the cathode material on the current collector. Voltage

[0057] It will be understood that throughout, unless otherwise specified, the voltages described herein are voltages relative to a standard hydrogen electrode.

[0058] In some embodiments, the voltage applied to the current collector in the deposition stage is about or less than about: -0.1, -0.2, -0.3, -0.4, -0.5, 0.6, -0.7, -0.8, -0.9, -1.0, -1.1, -1.2, -1.3, -1.4, -1.5, -1.6, -1.7, -1.8, -1.9, -2.0, -2.1, -2.2, -2.3, -2.4, -2.5, -2.6, -2.7, -2.8, -2.9, -3.0, - 3.1, -3.2, -3.3, -3.4, -3.5, -3.6, -3.7, -3.8, -3.9, or -4.0. In some embodiments, the voltage applied to the current collector in the deposition stage is greater than about: -4.0, -3.9, -3.8, -3.7, -3.6, - 3.5, -3.4, -3.3, -3.2, -3.1, -3.0, -2.9, -2.8, -2.7, -2.6, -2.5, -2.4, -2.3, -2.2, -2.1, -2.0, -1.9, -1.8, - 1.7, -1.6, -1.5, -1.4, -1.3, -1.2, -1.1, -1.0, -0.9, -0.8, -0.7. -0.6. -0.5. -0.4, -0.3. -0.2, -0.1. In some embodiments, the voltage applied to the current collector in the deposition stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about -0.7 to about -4.0.

[0059] In some embodiments, the voltage applied to the current collector in the deposition stage is less than -0.1 V relative to a standard hydrogen electrode.

[0060] In some embodiments, the voltage applied to the current collector in the deposition stage is between about -0.1 V to about -4.0 V relative to a standard hydrogen electrode.

[0061] In some embodiments, the voltage applied to the current collector in the deposition stage is less than about -2.5 V relative to a standard hydrogen electrode.

[0062] In some embodiments, the voltage applied to the current collector in the deposition stage is between about -0.1 V to about -2.5 V relative to a standard hydrogen electrode.

[0063] In some embodiments, the voltage applied to the current collector in the deposition stage is less than -0.7 V relative to a standard hydrogen electrode.

[0064] In some embodiments, the voltage applied to the current collector in the deposition stage is between about -0.7 V to about -4.0 V relative to a standard hydrogen electrode.

[0065] In some embodiments, the voltage applied to the current collector is more negative in the deposition stage compared to the first stage.

[0066] In some embodiments, wherein the voltage applied to the current collector in the first stage is about 0.0 V relative to a standard hydrogen electrode. Current

[0067] In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) 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, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13,3, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) is less than about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01. In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) may be in a range provided by any two or more of the upper and / or lower amounts. In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) is between about 0.01 to about 20. In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) is between about 0.05 to about 10. In some embodiments, the voltage applied is such that the current to the current collector per unit area (mA / cm2) is between about 0.1 to about 2.

[0068] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) 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, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13,3, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, or 50. In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is less than about 50, 45, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01. In some embodiments, the voltageapplied is such that the current to the substrate per unit area (mA / cm2) may be in a range provided by any two or more of the upper and / or lower amounts.

[0069] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is between about 0.01 to about 50.

[0070] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is between about 0.1 to about 50.

[0071] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is between about 0.01 to about 20.

[0072] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is between about 0.05 to about 10.

[0073] In some embodiments, the voltage applied is such that the current to the substrate per unit area (mA / cm2) is between about 0.1 to about 2.

[0074] In some embodiments, the current applied to the current collector per unit area (mA / cm2) 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, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13,3, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, or 50. In some embodiments, the current applied to the current collector per unit area (mA / cm2) is less than about 50, 45, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01. In some embodiments, the current applied to the current collector per unit area (mA / cm2) may be in a range provided by any two or more of the upper and / or lower amounts, for example the current applied to the current collector per unit area (mA / cm2) is between about 0.01 to about 20, between about 0.05 to about 10, between about 0.1 to about 2.

[0075] In some embodiments, the current applied to the current collector per unit area (mA / cm2) is between about 0.01 to about 10.

[0076] In some embodiments, the current applied to the current collector per unit area (mA / cm2) is between about 0.1 to about 2.

[0077] In some embodiments, the current applied to the substrate per unit area (mA / cm2) 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, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13,3, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, the current applied to the substrate per unit area (mA / cm2) is less thanabout 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01. In some embodiments, the current applied to the substrate per unit area (mA / cm2) may be in a range provided by any two or more of the upper and / or lower amounts, for example the current applied to the substrate per unit area (mA / cm2) is between about 0.01 to about 20, between about 0.05 to about 10, between about 0.1 to about 2.

[0078] In some embodiments, the current applied to the substrate per unit area (mA / cm2) is between about 0.01 to about 10.

[0079] In some embodiments, the current applied to the substrate per unit area (mA / cm2) is between about 0.1 to about 2. Local pH ranges for processes

[0080] In some embodiments, the pH at the deposition stage is about or less than about: 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 0r 22.0. In some embodiments, the pH at the deposition stage is greater than about 22.0, 21.5, 21.0, 20.5, 20.0, 19.5, 19.0, 18.5, 18.0, 17.5, 17.0, 16.5, 16.0, 15.5, 15.0, 14.5, 14.0, 13.5, 13.0, 12.5, 12.0, 11.5, 11.0, 10.5, or 10. In some embodiments, the pH at the deposition stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 12.0 to about between about 12.0 to about 22.0, 16.5, between about 12.0 to about 14.0, about 12.5 to about 14.5.

[0081] In some embodiments, the pH at the deposition stage is greater than about 10. In some embodiments, the pH at the deposition stage is greater than about 11.

[0082] In some embodiments, the pH at the deposition stage is greater than about 10. In some embodiments, the pH at the deposition stage is between about 11 to about 16.5.

[0083] In some embodiments, the pH at the deposition stage is greater than about 12.

[0084] In some embodiments, the pH at the deposition stage is between about 10 to about 22.0. In some embodiments, the pH at the deposition stage is between about 12 to about 22.0. In some embodiments, the pH at the deposition stage is between about 14 to about 18.0.

[0085] In some embodiments, the pH at the deposition stage is between about 12 to about 16.5.

[0086] In some embodiments, the pH at the deposition stage is between about 14.5 to about 16.5.

[0087] In some embodiments, the local pH adjacent to the substrate at the deposition stage is about or less than about: 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, or 22.0. In some embodiments, the local pH adjacent to the substrate at the deposition stage is greater than about 22.0, 21.5, 21.0, 20.5, 20.0, 19.5, 19.0, 18.5, 18.0, 17.5, 17.0, 16.5, 16.0, 15.5, 15.0, 14.5, 14.0, 13.5, 13.0, 12.5, 12.0, 11.5, 11.0, 10.5, or 10.0. In some embodiments, the local pH adjacent to the substrate at the deposition stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 12.0 to about between about 12.0 to about 22.0, 16.5, between about 12.0 to about 14.0, about 12.5 to about 14.5.

[0088] In some embodiments, the pH adjacent to the substrate at the deposition stage is greater than about 10. In some embodiments, the pH adjacent to the substrate at the deposition stage is greater than about 11.

[0089] In some embodiments, the local pH adjacent to the substrate at the deposition stage is greater than about 12.

[0090] In some embodiments, the pH adjacent to the substrate at the deposition stage is between about 10 to about 22.0. In some embodiments, the pH adjacent to the substrate at the deposition stage is between about 12 to about 22.0. In some embodiments, the pH adjacent to the substrate at the deposition stage is between about 14 to about 18.0.

[0091] In some embodiments, the local pH adjacent to the substrate at the deposition stage is between about 12 to about 16.5.

[0092] In some embodiments, the pH adjacent to the substrate at the deposition stage is between about 14.5 to about 16.5.

[0093] In some embodiments, the local pH adjacent to the current collector at the deposition stage is about or less than about: 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, or 22.0. In some embodiments, the local pH adjacent to the current collector at the deposition stage is greater than about 22.0, 21.5, 21.0, 20.5, 20.0, 19.5, 19.0, 18.5, 18.0, 17.5, 17.0, 16.5, 16.0, 15.5, 15.0, 14.5, 14.0, 13.5, 13.0, 12.5, 12.0, 11.5, 11.0, 10.5, or 10.0. In some embodiments, the local pH adjacent to the current collector at the deposition stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 12.0 to about between about 12.0 to about 22.0, 16.5, between about 12.0 to about 14.0, about 12.5 to about 14.5.

[0094] In some embodiments, the pH adjacent to the current collector at the deposition stage is greater than about 10. In some embodiments, the pH adjacent to the substrate at the deposition stage is greater than about 11.

[0095] In some embodiments, the local pH adjacent to the current collector at the deposition stage is greater than about 12.

[0096] In some embodiments, the pH adjacent to the current collector at the deposition stage is between about 10 to about 22.0. In some embodiments, the pH adjacent to the current collector at the deposition stage is between about 12 to about 22.0. In some embodiments, the pH adjacent to the current collector at the deposition stage is between about 14 to about 18.0.

[0097] In some embodiments, the local pH adjacent to the current collector at the deposition stage is between about 12 to about 16.5.

[0098] In some embodiments, the pH adjacent to the current collector at the deposition stage is between about 14.5 to about 16.5.

[0099] In some embodiments, the local pH adjacent to the substrate at the first stage is about or less than about: 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, or 12.0. In some embodiments, the local pH adjacent to the substrate at the first stage is greater than about 12.0, 11.5, 11.0, 10.5, 10.0, 9.5, 9.0, 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, or 0.0. In some embodiments, the pH at the first stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 0.0 to about 12.0, between about 5.0 to about 9.0, or about 6.0 to about 8.0.

[0100] In some embodiments, the local pH adjacent to the current collector at the first stage is about or less than about: 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, or 12.0. In some embodiments, the local pH adjacent to the current collector at the first stage is greater than about 12.0, 11.5, 11.0, 10.5, 10.0, 9.5, 9.0, 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, or 0.0. In some embodiments, the pH at the first stage may be in a range provided by any two or more of the upper and / or lower amounts, for example, between about 0.0 to about 12.0, between about 5.0 to about 9.0, or about 6.0 to about 8.0. Temperature

[0101] In some embodiments, the electrodeposition is performed at a temperature (in ˚C) of about, or greater than about: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95. In some embodiments, the electrodeposition is performed at a temperature (in ˚C) of less than about: 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5. In some embodiments, the electrodeposition is performed at a temperature (in ˚C) which may be in a range provided by any two or more of the upper and / or lower amounts, for example, electrodeposition is performed at a temperature (in ˚C) of between about 5 to about 95, or between about 15 to about 35, or between about 20 to about 30.

[0102] In some embodiments, the electrodeposition is performed at a temperature (°C) of between about 5 to about 95.

[0103] In some embodiments, the electrodeposition is performed at a temperature (°C) of between about 15 and 35.

[0104] In some embodiments, the electrodeposition is performed at a temperature (°C) of about 25. Salts Alkali metal salts

[0105] In some embodiments, the one or more salts comprising cations of alkali metals may be selected from any suitable salt or combination of salts.

[0106] In some embodiments, the one or more salts comprising the cation of the alkali metal are one or more of sodium salts, lithium salts, potassium salts, and combinations thereof. In some embodiments, the one or more salts comprising the cation of the alkali metal are one or more of sodium salts, lithium salts, and combinations thereof. In some embodiments, the one or more salts comprising the cation of the alkali metal are sodium salts.

[0107] In some embodiments, the one or more salts comprising cations of alkali metals comprises anions of one or more of Cl-, SO42-, NO3-, CO32-, OH-, PO43-, C2H3O2-, CH3COO-, C6H5O73-, C2O42-, Br-, I-, F-, and combinations thereof.

[0108] In some embodiments, the one or more salts comprising cations of alkali metals are selected from salts comprising Na+, Li+, and combinations thereof. In some embodiments, the one or more salts comprising cations of alkali metals are selected from one or more of NaOH, Na2SO4, NaCl, NaNO3, and Na2C2O4, Na2CO3, Na3C6H5O7, LiOH, Li2SO4, LiCl, LiNO3, and Li2C2O4, Li2CO3, Li3C6H5O7, and combinations thereof.

[0109] In some embodiments, the one or more salts comprising cations of alkali metals are selected from salts comprising Na+. In some embodiments, the one or more salts comprising cations of alkali metals are selected from one or more of NaOH, Na2SO4, NaCl, NaNO3, and Na2C2O4, Na2CO3, Na3C6H5O7, and combinations thereof.

[0110] In some embodiments, the one or more salts comprising cations of alkali metals are selected from salts comprising Li+. In some embodiments, the one or more salts comprising cations of alkali metals are selected from one or more of LiOH, Li2SO4, LiCl, LiNO3, and Li2C2O4, Li2CO3, Li3C6H5O7, and combinations thereof. Transition metal salts

[0111] In some embodiments, the one or more salts comprising cations of comprising transition metal cations may be selected from any suitable salt or combination of salts.

[0112] It will be understood that the transition metal cations may present in the aqueous solution as one or more cations and / or one or more oxyanions comprising a transition metal cation.

[0113] In some embodiments, the one or more salts comprising transition metal cations comprises anions of one or more of Cl-, SO42-, NO3-, CO32-, OH-, PO43-, C2H3O2-, CH3COO-, C6H5O73-, C2O42-, Br-, I-, F-, oxyanion of a transition metal and combinations thereof.

[0114] In some embodiments, the one or more salts comprising transition metal cations are selected from salts comprising one or more of Mn, Fe, Ni, Mo, and combinations thereof.

[0115] In some embodiments, the one or more salts comprising transition metal cations further comprise cations of one or more alkali metals.

[0116] In some embodiments, the one or more salts comprising transition metal cations are selected from one or more of MoCl5, KMnO4, NaMoO4, NaFeO4, NiSO4, MnSO4, FeSO4, and combinations thereof. Salt concentration

[0117] In some embodiments, the concentration (in M) of the cations of alkali metals in the aqueous solution 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, 13,3, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, or 60. In some embodiments, the concentration (in M) of the cations of alkali metals in the aqueous solution is less than about: 60, 55, 50, 45, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 0.1. In some embodiments, theconcentration (in M) of the cations of alkali metals in the aqueous solution may be in a range provided by any two or more of the upper and / or lower amounts, for example the concentration (in M) of the cations of alkali metals in the aqueous solution is between about 0.1 to about 60, between about 5 to about 60, or between about 10 to about 20.

[0118] In some embodiments, the concentration (in M) of the cations of alkali metals in the aqueous solution is between about 5 to about 60.

[0119] In some embodiments, the concentration (in M) of the cations of alkali metals in the aqueous solution is between about 10 to about 20.

[0120] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is about, or greater than about 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 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, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is less than about 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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, 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 concentration (in M) of the one or more transition metals cations in the aqueous solution may be in a range provided by any two or more of the upper and / or lower amounts, for example the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.0001 to about 5, between about 0.0001 to about 1, or between about 0.005 to about 0.010.

[0121] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is greater than about 0.1.

[0122] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.1 and about 5.

[0123] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.1 and about 30.

[0124] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.0001 to about 1.

[0125] In some embodiments, the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.005 to about 0.010.

[0126] In some embodiments, the ratio of cations of alkali metals to cations of transition metals in the aqueous solution precludes corrosion. That is the ratio of cations of alkali metals to cations of transition metals in the aqueous solution is in the non-corrosive range.

[0127] In some embodiments, the stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution 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, 13,3, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100. In some embodiments, the stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution is less than about: 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 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 stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution may be in a range provided by any two or more of the upper and / or lower amounts, for example the stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution is between about 1 to about 100.

[0128] In some embodiments, the stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution is between about 1 to about 100.

[0129] In some embodiments, the stoichiometric ratio of cations of alkali metals to cations of transition metals in the aqueous solution is between about 10 to about 60.

[0130] 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 described herein the alkali cation to transition metal cation ratio can be as low as 1, which is safe, green, and scalable. Solid phase stability

[0131] In some embodiments, the one or more transition metal cations are in soluble form along the pH-voltage pathway until about the deposition stage.

[0132] In some embodiments, the layered transition metal oxide is the only solid phase stable on a pH-voltage pathway defined between the first stage and the deposition stage.

[0133] In some embodiments, no solid phase of the one or more transition metal cations is stable along the pH-voltage pathway except for the layered transition metal oxide at and / or about the deposition stage. pH-voltage pathway

[0134] In some embodiments, the pH-voltage pathway is determined by reference to a Pourbaix diagram.

[0135] In some embodiments, the process further comprises generating the Pourbaix diagram for the combination of alkali metal cations and transition metal cations.

[0136] In some embodiments, the changing the pH and / or the changing the voltage defines a pH-voltage pathway between the first stage and the deposition stage.

[0137] In some embodiments, the changing the pH from the first stage to the deposition stage occurs in one or more intervals.

[0138] In some embodiments, the changing of the pH is achieved by addition of one or more hydroxide salts to the aqueous solution. In some embodiments, the changing of the pH is achieved by addition of NaOH, NH4OH, and / or combinations thereof to the aqueous solution.

[0139] In some embodiments, the changing the voltage from the first stage to the deposition stage occurs in one or more intervals.

[0140] In some embodiments, the pH of the first stage is less than the pH in the deposition stage. Heat treatment

[0141] In some embodiments, the process further comprises heat treatment of the cathode material deposited on the current collector.

[0142] In some embodiments, the heat treatment is performed in an environment comprising air, oxygen, nitrogen, helium, argon, or a mixture thereof.

[0143] In some embodiments, the heat treatment is performed at a temperature (in ˚C) of about, or greater than about: 50, 100, 15, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, or 1000. In some embodiments, the heat treatment is performed at a temperature (in ˚C) of less than about: 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 150, 100, or 50. In some embodiments, the heat treatment is performed at a temperature (in ˚C) which may be in a range provided by any two or more of the upper and / or lower amounts, for example, electrodeposition is performed at a temperature (in˚C) of between about 50 to about 1000, or between about 100 to about 600, or between about 300 to about 400.

[0144] In some embodiments, the heat treatment is performed at a temperature (°C) of between about 100 to about 600.

[0145] In some embodiments, the heat treatment is performed at a temperature (°C) of between about 300 to about 400.

[0146] In some embodiments, the heat treatment is performed at a temperature (°C) of about 350.

[0147] In some embodiments, the heat treatment is performed is heated for a period of time (hours) of 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, 13,3, 14, 15, 16, 17, 18, 19, or 20, 24 or 48. In one embodiment, the heat treatment is performed for a period of time (hours) of less than about: 48, 24, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1. The heat treatment is performed may be performed for a period of time in a range provided by any two of these upper and / or lower values, for example between about 0.1 to about 48 hours, or between about 1 to about 24 hours.

[0148] In some embodiments, the heat treatment is performed for a period of time (hours) of between about 1 to about 10.

[0149] In some embodiments, the heat treatment is performed for a period of time (hours) of between about 3 to about 5.

[0150] In some embodiments, the heat treatment is performed for a period of time (hours) of about 4. Additional process steps

[0151] In some embodiments, a process as described herein comprises one or more additional process steps.

[0152] In some embodiments, the process further comprises stirring the aqueous solution. In some embodiments, the process further comprises stirring the aqueous solution during at least a portion of the deposition stage.

[0153] In some embodiments, the process further comprises pre-treating the current collect. In some embodiments, the process further comprises pre-treating the substrate. In some embodiments, the pre-treating the current collector comprises washing the current collector. In some embodiments, the pre-treating the substrate comprises washing the substrate. In someembodiments, the washing is performed in a wash solution. In some embodiments, the wash solution comprises water, an organic solvent, and combinations thereof. In some embodiments, the wash solution comprises water, a polar organic solvent, and combinations thereof. In some embodiments, the wash solution comprises water and a C1-C6 alcohol. In some embodiments, the wash solution comprises water and ethanol. Cathode material powder

[0154] In some embodiments, the process further comprises removing at least a portion of the cathode material from the substrate to obtain a cathode material. In some embodiments, the process further comprises removing the cathode material from the substrate to obtain a cathode material.

[0155] In some embodiments, the cathode material is a cathode material powder.

[0156] 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).

[0157] 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, 750500, 400, 300, 200, 150, 100, 75, 50, 25, 20, 15, 10, 5, 2 or 1. In some embodiments, the cathode material powder 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. Deposition

[0158] In some embodiments, the cathode material deposited on the current collector is a cathode material as described herein.

[0159] In some embodiments, the cathode material deposited on the substrate is a cathode material as described herein.

[0160] In some embodiments, the process involves a single stage of electrodeposition of the cathode material on the current collector.

[0161] In some embodiments, the process involves a single stage of electrodeposition of the cathode material on the substrate.Cathode material

[0162] The present disclosure relates process for producing cathode materials and cathodes comprising said cathode material.

[0163] 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.

[0164] 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.

[0165] 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 Na+. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Li+. In some embodiments, the metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is K+.

[0166] 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.

[0167] 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 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 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+.

[0168] 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.

[0169] 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 comprises one or more alkali metal cations is Na+. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is Li+. In some embodiments, the layered transition metal oxide incorporating an alkali metal cation comprises one or more alkali metal cations is K+.

[0170] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of birnessite.

[0171] In some embodiments, at least a portion of the cathode material has a crystal structure that is isomorphous with that of birnessite.

[0172] 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.

[0173] 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.

[0174] In some embodiments, the cathode material is substantially anhydrous.

[0175] In some embodiments, the cathode material is anhydrous.

[0176] In some embodiments, the cathode material comprises less than 1 %w / w water.

[0177] In an 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, and wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite. Birnessite crystal structure

[0178] 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 NaMnO2.nH2O, and with a stoichiometry defined as (Na0^7Ca0^3)Mn7O14^2.8H2O. 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.

[0179] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite.

[0180] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 12.5° ± 0.2°. In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 25° ± 0.2°. In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite characterised by an X-ray diffraction (XRD) pattern comprising a characteristic peak at about 37° ± 0.2°. In some embodiments, at least a portion of the cathode material has a crystalstructure that is substantially isomorphous with that of δ-birnessite characterised by an X-ray diffraction (XRD) pattern comprising characteristic peaks at about 12.5° ± 0.2° and at about 25° ± 0.2°. In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite 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°.

[0181] In some embodiments, at least a portion of the cathode material has a crystal structure that is substantially isomorphous with that of δ-birnessite, wherein δ-birnessite 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. Birnessite in layered transition metal oxide

[0182] 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, 6560, 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 birnessite (% 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 birnessite. In some embodiments, 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 layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 70 %w / w of the layered transition metal oxide is isomorphous with birnessite. In some embodiments, at least 80 %w / w of the layered transition metal oxide is isomorphous with birnessite.

[0183] 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° 2θ. 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° 2θ (% w / wbased 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.

[0184] 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° 2θ. 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° 2θ (% 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.

[0185] 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° 2θ. 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° 2θ (% 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.

[0186] 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.

[0187] 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° 2θ. 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° 2θ (% 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.Layered transition metal oxide in cathode material

[0188] 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, 6560, 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 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 80 %w / w of the cathode material is the layered transition metal oxide.

[0189] 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

[0190] 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.

[0191] 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, 10.95, 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.

[0192] 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 total weight 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.

[0193] 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.

[0194] 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. Alkali metal cations

[0195] 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+.

[0196] 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+.

[0197] In some embodiments, the one or more alkali metal cations is selected from Na+.Transition metals

[0198] 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.

[0199] 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.

[0200] 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 from Ti, 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.

[0201] 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.

[0202] 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.

[0203] 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, the layered transition metal oxide comprises of one or more transition metal cations of three elements selected from Mn, Fe, Ni, and Mo.

[0204] 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

[0205] 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. 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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. 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.

[0211] 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. Cathode

[0212] Disclosed herein is a cathode comprising: a cathode material as described herein; and a current collector.

[0213] Disclosed herein is 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, wherein at least a portion of the layered transition metal oxide is isomorphous with birnessite; and a current collector.

[0214] In some embodiments, the cathode is obtained from the process as described herein.

[0215] In some embodiments, the cathode is for a rechargeable battery. Current collector

[0216] 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.

[0217] In some embodiments, the current collector is a foil, mesh, foam, or plate current collector.

[0218] In some embodiments, the current collector comprises aluminium, copper, or combinations thereof.

[0219] In some embodiments, the current collector comprises aluminium, FTO, ITO, ferrous alloy, or carbon.

[0220] In some embodiments, the current collector is an aluminium based current collector.

[0221] The current collector may have any suitable thickness. In some embodiments, the thickness of the current collector (in µm) 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 µm) 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 µm) may be a range provided by any two of these upper and / or lower values, for example, between about 10 µm to about 1000 µm, or between about 50 to about 200. Substrate

[0222] The substrate may be any suitable current collector used to prepare electrodes. The current collector may have a morphology and / or properties effective to support the cathodematerial. In some embodiments, the current collector is selected from a metal, carbon-based, or oxide-based current collector.

[0223] In some embodiments, the substrate is a foil, mesh, foam, or plate current collector.

[0224] In some embodiments, the substrate comprises aluminium, copper, or combinations thereof.

[0225] In some embodiments, the substrate comprises aluminium, FTO, ITO, ferrous alloy, or carbon, or a mixture thereof.

[0226] In some embodiments, the substrate is an aluminium based current collector.

[0227] The substrate may have any suitable thickness. In some embodiments, the thickness of the substrate (in µm) 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 substrate (in µm) 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 substrate (in µm) may be a range provided by any two of these upper and / or lower values, for example, between about 10 µm to about 1000 µm, or between about 50 to about 200. Cathode material film

[0228] In some embodiments, the cathode material is a film on one or more surfaces of the current collector.

[0229] In some embodiments, the cathode material is a film on one or more surfaces of the substrate.

[0230] The thickness of the film is measured by Transmission Electron Microscopy (TEM), and / or Scanning Electron Microscopy (SEM) imaging.

[0231] In some embodiments, the thickness of the film (in µm) is about, or greater than about: 1, 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 µm) 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 µm) 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.

[0232] In some embodiments, the thickness of the film (μm) is between about 1 to about 500.

[0233] In some embodiments, the thickness of the film (μm) is between about 100 to about 300.

[0234] In some embodiments, the thickness of the film (μm) is about 200.

[0235] In some embodiments, the cathode does not contain a binder.

[0236] In some embodiments, the cathode does not contain a conductive agent.

[0237] In some embodiments, the cathode substantially consists of: a cathode material as described herein; and a current collector.

[0238] 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, 11, 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.

[0239] In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is between about 0.1 and about 75. In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is between about 1 and about 50. In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is between about 1 and about 40. In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is between about 1 and about 20. In some embodiments, the mass loading of the cathode material on the current collector (mg / cm2) is between about 10 and about 40.

[0240] 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 totalweight 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.

[0241] 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.

[0242] In some embodiments, the thickness of the electrode (in µm) 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 electrode (in µm) 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 electrode (in µm) 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 electrode (in µm) is about 400. Products

[0243] In a fifth aspect, there is provided a cathode obtained from the process described herein.

[0244] In a sixth aspect, there is provided a cathode material obtained from the process described herein.

[0245] In a seventh aspect, there is provided a cathode material powder obtained from the process described herein. Use

[0246] Disclosed herein is the use of the cathode material obtained from the process described herein in the manufacture of a cathode.

[0247] Disclosed herein is the use of the cathode material powder obtained from the process described herein in the manufacture of a cathode.

[0248] Disclosed herein is the use of the cathode obtained from the process described herein in the manufacture of an electrochemical cell.

[0249] Disclosed herein is the use of the cathode material obtained from the process described herein in the manufacture of an electrochemical cell.

[0250] Disclosed herein is the use of the cathode material powder obtained from the process described herein in the manufacture of an electrochemical cell. EXAMPLE EMBODIMENTS

[0251] The present disclosure may be described by one or more of the following example embodiments.1. A process for forming a cathode, the process comprising:providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: hydrogen is evolved at and / or near the current collector in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.2. A process for the electrodeposition of a cathode material on a substrate, the processcomprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein: hydrogen is evolved at and / or near the substrate in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.3. The process according to example embodiment 2, further comprising removing at least a portion of the cathode material from the substrate to obtain a cathode material, optionally wherein the cathode material is a cathode material powder. 4. The process according to any one of the preceding example embodiments, wherein the local pH adjacent the current collector or the substrate at the deposition stage is greater than about 11, optionally the pH is between about 11 to about 16.5. 5. The process according to any one of the preceding example embodiments, wherein the local pH adjacent the current collector or the substrate at the deposition stage is greater than about 12, optionally the pH is between about 12 to about 16.5. 6. The process according to any one of the preceding example embodiments, wherein the pH of the first stage is less than the pH in the deposition stage. 7. The process according to any one of preceding example embodiments, wherein the voltage applied to the current collector is more negative in the deposition stage compared to the first stage. 8. The process according to any one of the preceding claims, wherein the voltage applied to the current collector or the substrate in the deposition stage is less than -0.1 V relative to a standard hydrogen electrode, optionally between about -0.1 and about -2.5 V. 9. The process according to any one of the preceding example embodiments, wherein the layered transition metal oxide is the only solid phase stable on a pH-voltage pathway defined between the first stage and the deposition stage. 10. The process according to any one of the preceding example embodiments, wherein the current applied to the current collector or the substrate per unit area (mA / cm2) is between about 0.1 to 50. 11. The process according to any one of the preceding claims, wherein the concentration (in M) of the one or more transition metal cations in the aqueous solution is between about 0.1 to about 30. 12. The process according to any one of the preceding example embodiments, wherein the concentration (in M) of the cations of alkali metals in the aqueous solution is between about 5 to about 60, optionally between about 10 to about 20.13. The process according to any one of the preceding example embodiments, wherein the ratio of cations of alkali metals to cations of transition metals in the aqueous solution precludes corrosion. 14. The process according to any one of the preceding example embodiments, wherein the one or more salts comprising the cation of the alkali metal are sodium salts, lithium salts, potassium salts, and combinations thereof. 15. The process according to any one of the preceding example embodiments, wherein the one or more salts comprising the cation of the alkali metal are sodium salts. 16. The process according to any one of the preceding example embodiments, wherein the one or more salts comprising cations of alkali metals are selected from NaOH, Na2SO4, NaCl, NaNO3, and Na2C2O4, Na2CO3, Na3C6H5O7, and combinations thereof. 17. The process according to any one of the preceding example embodiments, wherein the one or more salts comprising the transition metal cation are selected from salts comprising Mn, Fe, Ni, Mo, and combinations thereof. 18. The process according to any one of preceding example embodiments, wherein the one or more salts comprising transition metal cations are selected from MoCl5, KMnO4, NaMoO4, NaFeO4, NiSO4, MnSO4, FeSO4, and combinations thereof. 19. The process according to any one of the preceding example embodiments, wherein the process further comprises heat treatment of the deposited cathode material. 20. The process according to any one of the preceding example embodiments, wherein the concentration (in M) of the one or more transition metals cations in the aqueous solution is between about 0.0001 to about 1, optionally between about 0.005 to about 0.010. 21. The process according to any one of the preceding example embodiments, wherein the voltage applied to the current collector or the substrate in the deposition stage is less than -0.7 V relative to a standard hydrogen electrode, optionally between about -0.7 and about -4.0 V. 22. The process according to any one of preceding example embodiments, wherein the current applied to the current collector or the substrate per unit area (mA / cm2) is between about 0.1 to about 2. 23. A cathode obtained by the process according to any one of example embodiments 1 or example embodiments 4 to 22 when appended to example embodiment 1 or a cathode materialobtained from the process of according to any one of example embodiment 2 or example embodiment 3 or example embodiments 4 to 22 when appended to example embodiment 2. EXAMPLES Potential cathode materials

[0252] Table 1 shows layered transition metal oxides within the scope of the present disclosure. Table 1: Layered transition metal oxides i z, y, x

[0253] 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 willbe 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

[0254] 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 obtained CathodePourbaix diagrams

[0255] 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 (s) 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 H2or O2.

[0256] The Pourbaix diagram provides a graphical representation that illustrates the thermodynamic stability of different chemical species of an element in aqueous environments. The diagram maps out which species are stable at various combinations of pH and electrode potential. Through collection and calculation of relevant thermodynamic data for all species of the element of interest, including, for example one or more of the standard Gibbs free energies of formation, standard electrode potentials, and / or solubility constants, a representation of the species which stable at various combinations of pH and electrode potential is produced. Theboundaries between stability regions on the diagram are determined by calculating where two species are in equilibrium. Each region on the graph shows the conditions under which a particular species is the most thermodynamically stable. Advantageously, the inventors of the present application, have discovered that, by referencing the generated Pourbaix diagrams for the system of interest, it is possible to define pH-voltage pathways between a first stage and a deposition stage, such that the desired cathode material is the most thermodynamically stable solid in the deposition phase while the necessary components are stable dissolved in solution in the first state. Furthermore, the inventors have discovered that, through referencing the Pourbaix diagram to define the pH-voltage pathway, it is possible to avoid the undesirable precipitation of compounds other than the desired cathode material by selecting a pH-voltage pathway where salts of transition metals are more thermodynamically stable in solution rather than as undesired secondary solids which could precipitate on the current collector or substrate.

[0257] Pourbaix diagrams show the (a) relevant TMOs that must be prepared and (b) the experimental conditions that must be applied to fabricate the TMOs.

[0258] Figure 1 illustrates a Pourbaix diagram generated for the ternary Na-Mn-H2O 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 (i.e., Na1.1MnO2), 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 MnO2-2 is to the right of the NaMnO2stability region. Consequently, it is likely that the NaMnO2stability region effectively consists of a gradient of Mn redox conditions, where the presence of H2gas causes progressive reduction of the Mn of NaMnO2. Consequently, it is likely that pH values >14.5 will result in progressively higher Na+intercalation capacities (x > 1.1).

[0259] 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 MnO2, which can be intercalated ex situ with Na+. The inventors have discovered that, compositions on the left side of the NaMnO2stability region require exiting the water-stability region while compositions on the right side of the NaMnO2 stability region (thus avoiding H2 generation) result in phase assemblages with only slightly more than 50 at%NaMnO2, 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+.

[0260] 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 was2 4In effect, this calculation sets a starting +Na intercalation capacity of x = 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 Fe20+.4level. 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 Na1.2Fe0.4Mn0.5O2stability region. General procedure

[0261] 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.

[0262] 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. Unary system

[0263] Sodium salt was dissolved in water to provide an 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 an 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 -1.3-2.5 vs SHE (typically 1.4 V) was applied at the current collector (working electrode) such that NaxMnyO2 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. Thevoltage 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 NaxMnyO2 was washed with water, dried, and annealed by maintaining a temperature between 100 and 400oC for 1 to 20 hours, under a nitrogen, air, argon, or vacuum atmosphere. Binary system

[0264] 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

[0265] 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

[0266] Figure 11 shows the electrochemical performance of coin half-cells incorporating the Na0.37MnO2 and Na1.1Mn1-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 μm), they remain flexible.

[0267] The reason for this is the unique ability of electrochemical deposition to form Na-rich foliate nanostructures of units of ≤4 μm diameter, each of which is comprised of 2D nanosheetarrays 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.

[0268] When cycled in the range 2.0-4.3 V vs Na / Na+, Na0.37MnO2 produced typical charge and discharge capacities of 150 and 145 mAh^g-1, respectively. However, when the technique was adapted to form Na1.1Mn1-xO2and 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.

[0269] Figure 6 shows the galvanostatic diagram showing charge / discharge capacities of Na- rich cathodes (Na1.1MnO2) 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).

[0270] Figure 11 shows the first-cycle galvanostatic charge / discharge capacities of the single TMO (Na0.37MnO2) and binary TMO (Na1.2Fe0.4Mn0.5O2) 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

[0271] NaxMnO2, where x > 1.0 and a (001) interlayer lattice spacing of ~7 Å 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 Å is occupied by water such that the actual composition and structure is NaxMnO2^1½H2O (x ≤ 1). The experimental data of cathode materials obtained from the process described herein confirm that the NaxMnO2(where x > 1.0) exhibits a (001) interlayer lattice spacing of ~7 Å 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 MnO2 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.

[0272] Figure 14 shows the X-ray diffraction patterns for experimental high-Na Na1.1MnO2 after a single charge / discharge cycle (top) and reference pattern for NaxMnO2^1½H2O, where0 ≤ x ≤ 1 (bottom); the key observation is that the lattice spacings (including the (001) plane spacing of ~7 Å) of the structure shifts only to slightly smaller values (i.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 the pattern (i.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.

[0273] In contrast, X-ray diffraction patterns for experimental low-Na Na0.37MnO2 after a single charge / discharge cycle (top) and reference pattern for P2-type monoclinic NaxMnO2, where 0 ≤ x ≤ 1 (bottom); the key observation is that the (001) plane spacing of the as- synthesised Na0.37MnO2, which is ~7.0 Å (Figure 14) is reduced to 5.3 Å after a single charge / discharge cycle and the XRD pattern becomes effectively identical with the known P2- type monoclinic NaxMnO2structure.

[0274] XRD patterns of the Fe-containing binary TMO synthesised according to the relevant high-Na salt indicated on the Pourbaix diagram (Na1.2Fe0.4Mn0.5O2 (black line)) and Mo- containing TMO NaxMo0.1Mn0.9O2(red line); the key observation is that the pattern is effectively identical to that of Na1.1MnO2, 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).

[0275] Figure 26 shows galvanostatic charge / discharge curves of Nax(Mn41+-xMn3x+)O2 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

[0276] 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-O) 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.

[0277] 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

CLAIMS 1. A process for forming a cathode, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to a current collector at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the current collector, wherein: hydrogen is evolved at and / or near the current collector in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

2. A process for the electrodeposition of a cathode material on a substrate, the process comprising: providing an aqueous solution comprising: one or more salts comprising a cation of an alkali metal, one or more salts comprising a transition metal cation of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Ta, W, Re, Os, and combinations thereof; changing the pH of the aqueous solution and / or changing the voltage applied to the substrate at least partially immersed in the aqueous solution from a first stage to a deposition stage such that the cathode material deposits on the substrate, wherein: hydrogen is evolved at and / or near the substrate in the deposition stage; and the cathode material is a layered transition metal oxide incorporating the cation of the alkali metal.

3. The process according to claim 2, further comprising removing at least a portion of the cathode material from the substrate to obtain a cathode material, optionally wherein the cathode material is a cathode material powder.

4. The process according to any one of the preceding claims, wherein the local pH adjacent the current collector or the substrate at the deposition stage is greater than about 11, optionally the pH is between about 11 to about 16.

5.

5. The process according to any one of the preceding claims, wherein the local pH adjacent the current collector or the substrate at the deposition stage is greater than about 12, optionally the pH is between about 12 to about 16.

5.

6. The process according to any one of the preceding claims, wherein the pH of the first stage is less than the pH in the deposition stage.

7. The process according to any one of preceding claims, wherein the voltage applied to the current collector is more negative in the deposition stage compared to the first stage.

8. The process according to any one of the preceding claims, wherein the voltage applied to the current collector or the substrate in the deposition stage is less than -0.1 V relative to a standard hydrogen electrode, optionally between about -0.1 and about -2.5 V.

9. The process according to any one of the preceding claims, wherein the layered transition metal oxide is the only solid phase stable on a pH-voltage pathway defined between the first stage and the deposition stage.

10. The process according to any one of the preceding claims, wherein the current applied to the current collector or the substrate per unit area (mA / cm2) is between about 0.1 to 50.

11. The process according to any one of the preceding claims, wherein the concentration (in M) of the one or more transition metal cations in the aqueous solution is between about 0.1 to about 30.

12. The process according to any one of the preceding claims, wherein the concentration (in M) of the cations of alkali metals in the aqueous solution is between about 5 to about 60, optionally between about 10 to about 20.

13. The process according to any one of the preceding claims, wherein the ratio of cations of alkali metals to cations of transition metals in the aqueous solution precludes corrosion.

14. The process according to any one of the preceding claims, wherein the one or more salts comprising the cation of the alkali metal are sodium salts, lithium salts, potassium salts, and combinations thereof.

15. The process according to any one of the preceding claims, wherein the one or more salts comprising the cation of the alkali metal are sodium salts.

16. The process according to any one of the preceding claims, wherein the one or more salts comprising cations of alkali metals are selected from NaOH, Na2SO4, NaCl, NaNO3, and Na2C2O4, Na2CO3, Na3C6H5O7, and combinations thereof.

17. The process according to any one of the preceding claims, wherein the one or more salts comprising the transition metal cation are selected from salts comprising Mn, Fe, Ni, Mo, and combinations thereof.

18. The process according to any one of preceding claims, wherein the one or more salts comprising transition metal cations are selected from MoCl5, KMnO4, NaMoO4, NaFeO4, NiSO4, MnSO4, FeSO4, and combinations thereof.

19. The process according to any one of the preceding claims, wherein the process further comprises heat treatment of the deposited cathode material.

20. A cathode obtained by the process according to any one of claims 1 or claims 4 to 19 when appended to claim 1 or a cathode material obtained from the process of according to any one of claim 2 or claim 3 or claims 4 to 19 when appended to claim 2.

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