PRODUCTION OF A LAYERED LITHIUM-MANGANESE-NICKEL-COBALT OXIDE MATERIAL THIS INVENTION relates to the production of a layered lithium-manganese-nickel-cobalt oxide material. It relates in particular to a process for producing a layered lithium-manganese-nickel-cobalt oxide material suitable for use as a cathode material in a lithium-ion electrochemical cell or battery, and to an electrochemical cell incorporating the layered lithium-manganese-nickel-cobalt oxide material. With the burgeoning world population and the ever increasing demand for energy, the world faces an energy crisis with fossil fuels being depleted and causing global warming. In an effort to keep up with these demands, energy conversion technologies, focussing on lithium-ion cell battery research, for energy storage, are at the forefront. It is known that layered lithium-manganese-nickel-cobalt oxide materials can be used as cathode materials in lithium-ion electrochemical cells or batteries; however, these known materials have limitations when used as cathode materials, including inadequate capacity, rate capability and capacity retention/cyclability. It is hence an object of this invention to provide a process for producing a layered lithium-manganese-nickel-cobalt oxide material which provides improved performance when used as a cathode material in a lithium-ion electrochemical cell or battery. Thus, according to a first aspect of the invention, there is provided a process for producing a layered lithium-manganese-nickel-cobalt oxide material, which includes producing a raw layered lithium-manganese-nickel-cobalt oxide ('LMNC') material; optionally, introducing a dopant capable of enhancing the performance of the layered LMNC material when used as a cathode material in an electrochemical cell, during the production of the raw layered LMNC material; before any annealing of the raw layered LMNC material is effected, subjecting it to microwave treatment, to obtain a treated material; and annealing the treated material, to obtain the layered LMNC material. The process is characterized thereby that the production of the raw layered LMNC material does not include any heat treatment at a temperature greater than 600°C, preferably not greater than 550°C, most preferably not greater than about 500°C. In particular, production of the raw layered LMNC material does not involve heat treatment which would result in annealing of the material prior to the microwave treatment thereof. The production of the raw layered LMNC material may include heat treatment at a temperature not exceeding 600°C, preferably not exceeding 550°C, typically not exceeding about 500°C. When no dopant is present, the layered LMNC material may be LitLio.2Mno.54Nio.13Coo.13P2, LitNio.33Mno.33Coo.33P2 (also known as 'NMC-333'), LitNio.4Mno.4Coo.2lO2 (also known as 'NMC-442'), or the like. Typically, the layered LMNC material is LitLio.2Mno.54Nio.13Coo.13P2. The raw layered LMNC material may, at least in principle, be produced by any appropriate process or method, such as a modified Pechini method, a sol-gel method, a co-precipitation method, or the like. Typically, however, the production of the raw layered LMNC material may be by means of a modified, one-step, powder-forming Pechini method. Thus, the production of the raw LMNC material may be effected by maintaining a solution comprising a dissolved lithium compound, a dissolved manganese compound, a dissolved nickel compound, a dissolved cobalt compound, optionally a dissolved dopant compound, a hydroxycarboxylic acid, and a polyhydroxy alcohol, at an elevated temperature T1, where T1 is below the boiling point of the solution, until the solution gels; maintaining the gel at an elevated temperature until it ignites and burns to form a Li-Mn-Ni-Co-0 powder; and calcining the Li-Mn-Ni-Co-0 powder to burn off carbon and/or other impurities present in the powder, thereby to obtain the raw layered LMNC material. The process may include forming the solution of the lithium compound, the manganese compound, the nickel compound, the cobalt compound, optionally the dissolved dopant compound, the hydroxycarboxylic acid, and the polyhydroxy alcohol. The forming of the solution may then include admixing a solution of the lithium compound dissolved in a solvent, a solution of the manganese compound dissolved in a solvent, a solution of the nickel compound dissolved in a solvent, a solution of the cobalt compound dissolved in a solvent, optionally a solution of the dopant compound dissolved in a solvent, the hydroxycarboxylic acid and the polyhydroxy alcohol. While the lithium compound, the manganese compound, the nickel compound, the cobalt compound and, optionally, the dopant compound can initially each be in the form of a separate solution in which each is dissolved, they are preferably all dissolved in the same solvent so that a single solution containing the dissolved lithium, manganese, nickel, cobalt, optionally dopant, compounds is then admixed with the hydroxycarboxylic acid and the polyhydroxy alcohol. The lithium, manganese, nickel and cobalt compounds are preferably water soluble so that water, preferably deionized water, can be used as the solvent of the solution. Thus, in particular, nitrates of lithium, manganese, nickel and cobalt may be used, i.e. LiN03, Mn(N03)2 (more particularly Mn(N03)2.4H20), Ni(N03)2 (more particularly Ni(N03)2.6H20) and Co(N03)2 (more particularly Co(N03)2.6H20) may be used. The solution may thus contain the necessary stoichiometric amounts of LiN03, Mn(N03)2.4H20, Ni(N03)2.6H20 and Co(N03)2.6H20 to obtain Li[Lio.2Mno.54Nio.13Coo.i3]02 as the end product. The dopant, when present, will, as set out hereinbefore, be selected to improve electrochemical performance, particularly stability, of the resultant layered LMNC material. The dopant may be an element of Groups MA, MIA or IVA of the Periodic Table of Elements. More particularly, the dopant may be aluminium, germanium or magnesium; however, preferably the dopant is an element of Group MIA of the Periodic Table of Elements, particularly aluminium. Such dopant compound will thus also be water soluble, and may be a nitrate of aluminium, e.g. AIN309.9H20. When the dopant is present, the end product will thus be a layeredlithiurm-manganese-nickel-cobalt-aluminium oxide ('LMNCA') material. The end product may then, in particular, be LitLio.2Mno.52Nio.13Coo.13Alo.odO2. Preferably, both the dopant introduction and the microwave treatment are effected. The metallic compounds, i.e. the lithium, manganese, nickel, cobalt and aluminium compounds, may instead be any other metallic salts (derived from both weak and strong acids such as the sulphates, carbonates, halides, and the acetates) other than the nitrates. The hydroxycarboxylic acid acts as a reduction agent, and may be citric acid. The polyhydroxy alcohol may be ethylene glycol or polyethylene glycol. The citric acid and the ethylene glycol may be present in the solution in an appropriate molar ratio of citric acid to ethylene glycol, e.g. about 1:4. The citric acid may initially be in the form of a solution thereof in water, particularly deionized water. The process may comprise initially heating the mixture of the citric acid solution and the ethylene glycol to the temperature T1 with stirring; thereafter, the solution of the lithium, manganese, nickel, cobalt and, when present, aluminium nitrates may be added slowly, e.g. dropwise, to the citric acid/ethylene glycol solution. As set out hereinbefore, T1 is below the boiling point of the solution comprising the solvent for the lithium, manganese, nickel, cobalt, and, when present, aluminium compounds; the dissolved lithium, manganese, nickel, cobalt and, when present, the aluminium, compounds; the hydroxycarboxylic acid and the polyhydroxy alcohol. It is important that T1 be below the boiling point of the solution, to prevent premature evaporation of the solvent and other components of the solution, i.e. to prevent such evaporation before the gel-forming reaction (polymer gel formation) is complete. When the solvent is water as hereinbefore set out, then 90°CsTi<100°C. Preferably, 11 may then be about 90°C. The elevated temperature at which the gel is maintained may be T2, where 90°C