DESC:FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & The Patent Rules, 2003 COMPLETE SPECIFICATION (See sections 10 & rule 13) 1. TITLE OF THE INVENTION A NOVEL, HIGH PERFORMANCE AND STABLE CATHODE MATERIAL FOR SODIUM ION BATTERIES AND ITS PREPARATION METHOD THEREOF 2. APPLICANT (S) NAME NATIONALITY ADDRESS INDIGENOUS ENERGY STORAGE TECHNOLOGIES PVT. LTD. IN I-10, 2nd Floor, Tides Business Incubator, IIT Roorkee, Roorkee-247667, Uttarakhand, India. 3. PREAMBLE TO THE DESCRIPTION COMPLETE SPECIFICATION The following specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION: [001] The present invention relates to the field of Sodium ion batteries. The present invention in particular relates to a cathode material for Sodium ion batteries and its method of preparation thereof. DESCRIPTION OF THE RELATED ART: [002] The cathode material for a sodium-ion battery, sodium vanadium phosphate (Na3V2(PO4)3), is a fast ion conductor having relatively high ionic conductivity, excellent thermal stability, large channels that allow sodium ions to pass through quickly, stable structure, high working voltage, high capacity and other advantages, it is considered to be the most promising cathode material for a sodium-ion battery. However, due to its disadvantages such as relatively low electrical conductivity, large electrochemical polarization and poor cycle performance, its actual electrochemical performance is poor and it is difficult to reach industrialization. [003] For the sodium-inserted cathode material, cathode material for a battery with NASICON (sodium super-ion conductor) structure has attracted extensive attention due to its advantages of three opens frame structure, high charge and discharge voltage, large energy storage capacity, rapid charge and discharge capability, and good cycle stability. [004] Currently, most researchers improve the electrochemical performance of Na3V2(PO4)3 by nano metering, coating conductive materials, and metal ion doping. Wherein, carbon coating is considered to be a very effective way to improve the electrochemical performance of Na3V2(PO4)3. However, cathode materials for a sodium-ion battery still have a big space for development, and the stable and high performance material need to be further improved. [005] Reference may be made to the following: [006] Publication No. US2021151767 relates to a cathode material for a sodium-ion battery with a coating structure and a preparation method therefor. An Na3V2(PO4)3/C cathode material is prepared by means of a sol-gel method. Synthesized zwitterionic polymers may be used as chelating agents and as a carbon source; the process is simple, can quickly form a gel, and the reaction time is shortened contains a zwitterionic structure which may be well dissolved with the precursor of sodium vanadium phosphate to form a stable carbon coating layer. Compared to the prior art, the cathode material for a sodium-ion battery of the present invention enhances the electrical conductivity and cycle performance of the cathode material by means of the doping of nitrogen and sulfur on carbon. At the same time, the prepared cathode material for a sodium-ion battery has sodium vacancies and maintains a stable structure during the process of sodium-ion intercalation/deintercalation. [007] Publication No. CN111994890 relates to a sodium vanadium phosphate composite cathode material and a preparation method thereof. The preparation method comprises the following steps of: proportionally mixing ammonium metavanadate, ammonium dihydrogen phosphate, sodium carbonate and sucrose, adding a proper amount of ethanol solution, putting the mixture into a planetary ball mill, carrying out ball milling to obtain sodium vanadium phosphate compound precursor slurry, and drying the precursor slurry to obtain a first sodium vanadium phosphate precursor; mixing the first precursor into deionized water, transferring the mixture to a nano-sprayer for reaction, after the reaction, taking out atomized powder, and sufficiently drying the atomized powder to obtain a sodium vanadium phosphate second precursor; and transferring the sodium vanadium phosphate second precursor into a tubular furnace and sintering under the protection of mixed gas to obtain the sodium vanadium phosphate composite cathode material. The composite material is applied to a sodium ion battery positive electrode, and the preparation and application difficulties that a traditional sodium vanadium phosphate material is difficult in chemical synthesis, complex in preparation means and relatively low in electrochemical performance are effectively solved. The NASICON type sodium vanadium phosphate is compounded with carbon, so that a sodium ion battery with good conductivity, high specific capacity and excellent cycling stability is obtained. [008] Publication No. CN111943161 relates to a preparation method and application of a sodium vanadium fluorophosphate and carbon composite secondary battery positive electrode material, and a preparation method and application of a battery positive electrode material. The invention aims to solve the problems of poor electronic conductivity, capacity and rate capability of the NVOPF improved by the existing method. The method comprises the following steps: preparing a low-valence vanadium solution; preparing hydrothermal mother liquor; preparing a three-dimensional carbon skeleton material; and4, conducting compounding to obtain the sodium vanadium fluorophosphate and carbon composite cathode material for the secondary battery. The first-circle specific charge capacity of the sodium ion battery prepared by the composite cathode material can reach 138 mAh.g<-1>, and the first-circle specific discharge capacity can reach 113 mAh.g<-1>. According to the prepared sodium ion battery, the first-circle specific charge capacity can reach 138 mAh.g <-1>, the first-circle specific discharge capacity can reach 113 mAh.g<1>, and the coulombic efficiency can be kept at 95%. According to the invention, the sodium vanadium fluorophosphate and carbon composite cathode material for the secondary battery can be obtained. [009] Publication No. CN111554914 relates to a lithium iron phosphate-sodium vanadium phosphate-carbon composite material and a preparation method and application thereof, the composite material has a multilayer core-shellstructure, and the preparation method comprises the following steps: preparing the lithium iron phosphate-carbon composite material; mixing the lithium iron phosphate-carbon composite material with asodium vanadium phosphate precursor, and performing ball milling; and calcining the ball-milled mixed raw material in a protective atmosphere. The composite material can be used for preparing a lithium ion battery cathode. The composite material with the lithium iron phosphate-sodium vanadium phosphate-carbon multilayer core-shell structure is prepared in a manner of combining ball milling with hot calcination. The preparation method is simple to operate, low in energy consumption and easy for large-batch preparation. The prepared composite material has a unique multi-layer core-shell structure, and is beneficial to rapid transmission of lithium ions. Due to the unique structure of the composite material, the composite material also shows excellent electrochemical performance under a low-temperature condition. [010] Publication No. CN110600726 relates to sodium ion battery cathode materials, and a Na-Ti-Mn oxide-based sodium ion battery cathode material and a preparation method thereof. The Na-Ti-Mn oxide-based sodium ion battery cathode material comprises the following raw materials: sodium compounds, nano TiO2, manganese compounds, vanadium pentoxide, non-carbon porous materials, functional adhesive and electrolyte additives. According to the Na-Ti-Mn oxide-based sodium ion battery cathode material and the preparation method thereof, Na3-Ti1.2-1.8-Mn0.7-1.3O6-V2O5-n serves as a matrixof a cathode material, and the Na3-Ti1.2-1.8-Mn0.7-1.3O6-V2O5-n is a hexagonal-crystal stable structure, thereby reducing small strain of structure and size of the cathode material, and increasing stability of the cathode material; the amorphous oxygen-deficient H-V2O5-x improves structural stability of Na<+> intercalation and deintercalation cathode materials, so that the sodium storage performance of the cathode material is enhanced; and the amorphous structure of the oxygen-deficient H-V2O5-x increases Na<+>diffusion rate and electronic conductivity, and the electronic conductivity and the electrochemical cycle stability of the cathode material are improved. [011] Publication No. RU2704186 relates to making Na-ion batteries. Method of producing cathode material containing NaVO(PO)F(0F/C composite material. The relatively high electrochemical performance is showed when the NaVPO<4>F/C composite material is taken as a sodium ion battery cathode. [020] Publication No. CN107195886 relates to a preparation method for a sodium vanadium pyrophosphate@carbon composite cathode material for preparing sodium vanadium pyrophosphate of a carbon-coated microsphere structure. The method comprises the following steps of carrying out hydrothermal treating and pre-sintering on a vanadium source and a carbon source to prepare vanadium oxide pre-coated with a carbon layer, carrying out ball milling with a sodium source and a phosphorus source, carrying out spray granulation to obtain a micro-spherical precursor, and roasting, washing and drying the precursor to obtain the sodium vanadium pyrophosphate of the carbon-coated microsphere structure. The sodium vanadium pyrophosphate@carbon composite cathode material prepared by the preparation method. The prepared material is a secondary microsphere formed by primary nano-particles, the material is used for a sodium-ion battery and has excellent electrochemical performance and industrial application prospect. [021] Publication No. CN107123796 relates to a Na4MnV(PO4)3/C composite material and a preparation method thereof as well as application of the Na4MnV(PO4)3/C composite material in a sodium-ion battery. The Na4MnV(PO4)3/C composite material is prepared from Na4MnV(PO4)3/C particles. A synthetic method of the Na4MnV(PO4)3/C composite material is characterized in that an organic matter is used as a reducing agent and a carbon source; low-price sodium source, manganese source and vanadium source are adopted to synthesize a carbon-coated Na4MnV(PO4)3 composite cathode material by a one-step solid-phase method. The preparation method has the advantages of simplicity, feasibility, mild conditions and high yield; when the prepared composite material is applied as a cathode material of the sodium-ion battery, the composite material shows high specific capacity, high working voltage, good cyclic stability and excellent rate capability. [022] Publication No. CN105914352 relates to a preparing method of a sodium ion battery cathode material Na3V2(PO4)3/C. The method is simple and time-saving in steps. The prepared Na3V2(PO4)3/C material is uniform in particles, high in specific discharge capacity and good in rate capacity and cyclic performance. [023] Publication No. CN105206831 relates to a preparation method for Na3V2O2x(PO4)2F3-2x (x is larger than or equal to 0 and less than or equal to superstructure microspheres formed by ordered self-assembly of primary nano-particles and used for a sodium-ion battery cathode material and belongs to the field of synthesis and application of battery materials. The preparation method has the advantages as follows: the synthesis operation temperature is low, the energy consumption is low and the synthesized Na3V2O2x(PO4)2F3-2x (x is larger than or equal to 0 and less than or equal to superstructure microspheres formed by ordered self-assembly of primary nano-particles not only can improve energy density, but also keep the electrochemical performance of nanometer-sized materials. [024] Publication No. CN105140468 relates to a preparation method for a cathode material Na3V2(PO4)3/C of a sodium ion battery. The preparation method comprises the following steps of: taking a high-valent vanadium source compound, a sodium source compound, a phosphorus source compound and a reducing agent as raw materials, weighing the reaction raw materials according to the molar ratio of a sodium element, a vanadium element and a phosphorus element of being 3:2:3 and the molar ratio of the reducing agent and the high-valent vanadium source compound of being 3:1 to 15:1, carrying out mechanical ball grinding for 2 to 20 hours, and reducing high-valent vanadium into low-valent vanadium at a normal temperature; and forwarding a precursor obtained through ball grinding in the step into an inert atmosphere or a reducing atmosphere, and carrying out heat preservation for 4 to 20 hours at 600-900 DEG C to obtain the Na3V2(PO4)3/C. The method has the advantages of short flow and low cost, and is easy to control, the prepared Na3V2(PO4)3/C is high in purity and crystallinity, and the production of the cathode material Na3V2(PO4)3/C of the sodium ion battery at a large scale is easy to realize. [025] Publication No. CN107093716 relates to a preparation method of a high-performance bis (trifluoromethanesulfony)imide salt ionic liquid modified sodium vanadium phosphate/carbon composite cathode material. The preparation process comprises the steps that firstly, a sodium source, a vanadium source and a phosphorus source are subjected to ball milling for 6-10 hours in an absolute ethyl alcohol medium and then dried; secondly, the obtained powder is pre-calcined in a tube furnace, and a precursor is obtained; thirdly, a small amount of carbon sources and a certain amount of bis(trifluoromethanesulfonyl)imide salt are added into the precursor, the mixture is subjected to ball milling with absolute ethyl alcohol as a medium and then dried, and powder id obtained; fourthly, the powder obtained in the third step is subjected to heat treatment in the tube furnace under the nitrogen atmosphere and then cooled, and an ionic liquid modified carbon-coated sodium vanadium phosphate sample is obtained. When the sample is used in a sodium-ion battery cathode material, compared with a sodium-ion battery cathode material without the ionic liquid modified carbon-coated sodium vanadium phosphate, the sodium-ion battery cathode material with the ionic liquid modified carbon-coated sodium vanadium phosphate is higher in specific discharge capacity and better in cycling stability. [026] Publication No. CN106025226 relates to a cathode material for a sodium-ion battery, a preparation method of the cathode material for the sodium-ion battery and the sodium-ion battery. The method that a metal oxide catalyzes carbon sources to grow graphene in situ provided by the invention realizes the free conversions of the carbon sources, thereby being beneficial to industrial mass production. Furthermore, a certain amount of organic carbon sources are added in the synthesis process of Na3V2 (PO4)3(Sodium Vanadium Phosphate), and catalyzed to generate graphene under the effect of metal oxide, namely vanadium oxide at low temperature, and the graphene is uniformly coated on the surfaces of vanadium phosphate sodium particles to form a uniform carbon network layer, so that the conductivities of the material ions and electrons are enhanced to improve electrochemical performance of the material. [027] Publication No. CN105655565 relates to a composite cathode material of a sodium-ion battery. The composite cathode material adopts a composite multi-core type core-shell structure, a core of the cathode material comprises multiple sodium vanadium phosphate coated with amorphous carbon layers and multiple fluorine sodium vanadium phosphate coated with amorphous carbon layers, and a gap between a shell and the core is filled with conductive macromolecules; outer layers of nanoscale sodium vanadium phosphate and fluorine sodium vanadium phosphate are coated with the amorphous carbon layers respectively, conductive macromolecule monomers have a polymerization reaction, prepared sodium vanadium phosphate coated with the amorphous carbon layers and fluorine sodium vanadium phosphate coated with the amorphous carbon layers are added to the mixture, the mixture is evenly mixed, an obtained mixture is subjected to spray-drying, and a target product is obtained. [028] Publication No. KR20140144912 relates to a positive electrode material of a sodium ion battery wherein the positive electrode material of a sodium ion battery includes vanadium based ortho-diphosphate (Na7V4(P2O7)4PO4). [029] Publication No. CN103594716 relates to a method for preparing a cathode material of a sodium-ion battery, namely sodium vanadium fluorophosphates. The method comprises the following steps: using a vanadium source, a phosphorus source and a carbon source as main synthetic raw materials; dissolving into deionized water according to the molar ratio 1:1:1.2 of vanadium: phosphorus: carbon, heating in water bath, and continuously stirring to obtain light green pulp; after vacuum drying, grinding, then transferring into a tube furnace, preburning in an inert atmosphere at a certain temperature rise rate, cooling and then taking out to obtain black VPO4/C precursor powder; mixing the VPO4/C with NaF according to a stoichiometric ratio, ball-milling for 3 hours, sending into the tube furnace, then roasting in the inert atmosphere at the certain temperature rise rate, and cooling along with the furnace to obtain a positive active material NaVPO4F/C. According to the invention, cheap and easily-obtained pentavalent vanadium oxide or trivalent vanadium oxide is used as the main raw materials to prepare the sodium vanadium fluorophosphates cathode material through a sol gel activated auxiliary two-step high-temperature solid phase method, and the sodium vanadium fluorophosphates cathode material has the advantages of good stability, uniform particle size and good electrochemical performance. Meanwhile, the method has the advantages of simple synthesis process, short period and low cost and is convenient for large-scale production. [030] Publication No. CN104362309 relates to a high-magnification sodium-ion battery composite cathode material and its preparation method and belongs to the technical field of battery materials. The preparation method of the high-magnification sodium-ion battery composite cathode material comprises the following steps: a sodium source, a vanadium source and a phosphorus source are added into a mixed solvent of hydrogen peroxide and deionized water; after stirring and dissolution, a carbon-source organic matter and oxidized graphene; oil bath, stirring and drying are carried out to obtain an xerogel precursor; and the xerogel precursor obtained undergoes presintering and sintering in argon atmosphere, so as to prepare the Na3V2(PO4)3 /carbon/graphene composite cathode material. Reaction equipment used in the invention is simple; operation is convenient; and cost is low. The preparation method is suitable for large-scale industrial production. In addition, the prepared Na3V2(PO4)3 particles are small in size, are wrapped by amorphous carbon and graphene and have good conductivity. When used as a sodium-ion battery composite cathode material, the Na3V2(PO4)3 particles show high specific capacity, good cycling stability and excellent rate capability. [031] Publication No. CN103000884 relates to a vanadium sodium phosphate composite material as well as a preparation method and an application thereof. The general formula of the composite material provided by the invention is C1-xNx-LaNabMcVd(PO4)3, wherein C1-xNx is carbon or carbon doped with nitrogen, L is one or two selected from Li and K; M is one or more than one selected from Mg, B, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ce, Y, Zr, Nb, Mo, Sn, La, Ta and W; and x, a, b, c and d are mol percents, wherein x is more than or equal to 0 and less than 1, a is more than or equal to 0 and less than 2, b is more than 1 and less than or equal to 3, c is more than or equal to 0 and less than or equal to 1, and d is more than or equal to 1 and less than or equal to 2. The invention also provides a preparation method and an application of the composite material. [032] Publication No. CN108242540 relates to a carbon coated sodium vanadium phosphate microsphere, a preparation method thereof and application of the carbon coated sodium vanadium phosphate microsphere in a sodium ion battery positive electrode material. The carbon coated sodium vanadium phosphate microsphere is formed by assembling sodium vanadium phosphate nanosheets coated with conductive carbon layers. The preparation method comprises the following steps: slowly adding a hydrogen peroxide solution containing dissolved vanadium pentoxide into an aqueous solution containing organic sodium salt, phosphorous source and nitrogen-containing organic matters, and uniformly stirring to obtain a mixed solution; transferring the mixed solution into a hydrothermal reaction kettle for a hydrothermal reaction to obtain sodium vanadium phosphate hydrogel; drying the sodium vanadium phosphate hydrogel, calcining in a protective atmosphere to obtain the carbon coated sodium vanadium phosphate microsphere with excellent crystallization, stable appearance, uniform size and excellent electrochemical performance. When the carbon coated sodium vanadium phosphate microsphere is applied to preparation of sodium ion batteries, a sodium ion battery with circulating stability and excellent rate capability can be obtained; and the preparation process of the carbon coated sodium vanadium phosphate microsphere is simple, the repeatability is high, and the application prospect is good. [033] Publication No. CN103779564 relates to a sodium vanadyl phosphate symmetrical sodium-ion battery material of which the morpholog is granular, tubular and lamellar, the sodium vanadyl phosphate nano particle size is 60-90nm, the sodium vanadyl phosphate nanotube is 20-30nm in diameter and is wound together in a curled manner, the sodium vanadyl phosphate nanosheet is 150-200nm in thickness and 5-6mum in length and width. The sodium vanadyl phosphate symmetrical sodium-ion battery material can be applied as the active material of the sodium-ion battery. The sodium vanadyl phosphate symmetrical sodium-ion battery material has excellent multiplying power, high specific capacity and good circulating stability when being used as the active material of the sodium-ion battery, and the whole battery has good circulating and multiplying power performances when the sodium vanadyl phosphate nano particles are used as the cathode and the anode of the battery; the process is simple, economical and practical. [034] In order to overcome above listed prior art, the present invention is related to the development of new composite material Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g , where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene and g = wt % vary from 0 to 5 wt.% of rest of the composite sample and its synthesis process, here a, u, v, w, x, y and z are mole % wherein a is = 0 and = 10, u is = 10 and < 50, v is = 02 and = 20 , w is = 02 and = 10, and x, y, z = 02 and = 10 derived from sol-gel synthesis procedure. The method includes synthesis of novel Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g , where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene composite as high performance and stable cathode material for Sodium ion batteries. [035] The present invention provides a novel, high performance and stable cathode material for Sodium ion batteries and its method of preparation thereof. OBJECTS OF THE INVENTION: [036] The principal object of the present invention is to provide a cathode material for Sodium ion batteries and its method of preparation thereof. [037] Another object of the present invention is to provide high performance and stable cathode material for Sodium ion batteries. SUMMARY OF THE INVENTION: [038] The present invention relates to cathode material for Sodium ion batteries and the method of synthesis of the cathode material of Sodium ion batteries. The invention is related to development of a new composite material Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g , where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene and g = wt % vary from 0 to 5 wt.% of rest of the composite sample and its synthesis process, here a, u, v, w, x, y and z are mole % wherein a is = 0 and = 10, u is = 10 and < 50, v is = 02 and = 20 , w is = 02 and = 10, and x, y, z = 02 and = 10. The inventive step includes synthesis of Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g , where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene. The invention could lead to the synthesis of high performance and stable cathode material for Sodium ion batteries. The preparation method to synthesize Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g , where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene composite is novel, facile and industrially scalable. BREIF DESCRIPTION OF THE INVENTION [039] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. [040] Fig. 1 is the XRD pattern of Na3V2-xAlx(PO4)3, where 10 = x = 50. [041] Fig. 2 is the constant current cycling data for the synthesized Na3V1.8Al0.2(PO4)3@C cathode material. [042] Fig. 3 is the XRD pattern of Na3V2-x-yAlxMny(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20. [043] Fig. 4 is the constant current cycling data for the synthesized Na3V1.75Al0.2Mn0.05(PO4)3@C cathode material. [044] Fig. 5 is the XRD pattern of Na3V2-x-yAlxMnyMgz(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20, and z = 0 and = 15. [045] Fig. 6 is the constant current cycling data for the synthesized Na3V1.58Al0.2Mn0.12Mg0.1(PO4)3@C cathode material. [046] Fig. 7 is the XRD pattern of XRD pattern of Na3V2-x-yAlxMnyTiz(PO4)3@C, here x is = 10 and = 50, y is =0 and = 20, and z = 0 and = 15. [047] Fig. 8 is the constant current cycling data for the synthesized Na3V1.63Al0.2Mn0.12Ti0.05(PO4)3@C cathode material. [048] Fig. 9 is the XRD pattern of NaV2-x-yAlxMnyTiz(PO4)3@C (MWCNT)a, here x is = 10 and = 50, y is = 0 and = 20, and z = 0 and = 15 and a varies from 0 to 5 wt.%. [049] Fig. 10 is the constant current cycling data for the synthesized Na3V1.58Al0.2Mn0.12Ti0.1(PO4)3@C (MWCNT) cathode material. [050] Fig. 11 is the XRD pattern of Na3V2-w-x-y-zAlwMnxTiyMgz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15. [051] Fig. 12 is the constant current cycling data for the synthesized Na3V1.53Al0.2Mn0.12Ti0.1Mg0.05(PO4)3@C cathode material. [052] Fig. 13 is the XRD pattern of Na3V2-w-x-y-zAlwMnxTiyMgz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15. [053] Fig. 14 is the constant current cycling data for the synthesized Na3V1.53Al0.2Mn0.12Mg0.1Ti0.05(PO4)3@C cathode material. [054] Fig. 15 is the XRD pattern of Na3V2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15. [055] Fig. 16 is the constant current cycling data for the synthesized Na3 V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 @C (using PVP) cathode material. [056] Fig. 17 is the XRD pattern of Na3-aLiaV2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here a = 0 and = 10, v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15. [057] Fig. 18 is the constant current cycling data for the synthesized Na2.93 Li0.07V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 @C cathode material. DETAILED DESCRIPTION OF THE INVENTION: [058] The present invention provides cathode material for Sodium ion batteries and the method of synthesis of the cathode material of Sodium ion batteries. The invention is related to development of a new composite material Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g, where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene and g = wt % vary from 0 to 5 wt.% of rest of the composite sample and its synthesis process, here a, u, v, w, x, y and z are mole % wherein a is = 0 and = 10, u is = 10 and < 50, v is = 02 and = 20, w is = 02 and = 10, and x, y, z = 02 and = 10. The inventive step includes synthesis of Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g, where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene. The invention could lead to the synthesis of high performance and stable cathode material for Sodium ion batteries. The preparation method to synthesize Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g, where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene composite is novel, facile and industrially scalable. [059] The process involves following synthesis steps; a) Mixing of vanadium pentoxide (V2O5) and oxalic acid in a certain mole ratio. b) Stirring of the solution at a certain temperature until a clear blue solution is obtained. c) Mixing of homogeneous dispersion of MWCNTs, rGO, MoS2, MXene, or any of two, three, or all four in water, ethanol, NMP, DMF, Isopropyl Alcohol (IPA) or any of two, three, or all five. d) Addition of Aluminium nitrate (Al(NO3)3•9H2O), Manganese acetate (Mn(CH3COO)2.4H2O),or Magnesium acetate (Mg(CH3COO)2.6H2O) or Tetrabutyltitanate (Ti(OBu)4) or Nickel nitrate hexahydrate (Ni(NO3)2.6H2O) or Iron (III) nitrate nonahydrate (Fe(NO3)3.9H2O), in a certain amount to the solution and stirred for some time. e) Addition of Monosodium phosphate (NaH2PO4), lithium acetate de-hydrates in certain mole ratio to the solution and stirred for some time. f) After that certain amount of solution of sucrose, glucose, PVP, PVA or any of two, three, or all four in D.I water is mixed in the above solution (e) and stirred for some time. g) Drop by drop mixing of certain amount of ethanol, Dimethyl formamide (DMF), or any of two, or both in the solution obtained from (f) and stirred. h) Solution obtained from (g) left on stirring at 90 °C until the solution converts to gel. i) The final obtained gel from (h) is dried in an oven . j) After drying, the material was grounded and then pre-heated in a tube furnace at certain temperature under (Ar+H2) gas environment. [060] The obtained material was then again grounded and heated in a tube furnace at certain temperature under (Ar+H2) gas environment. The final obtained material is Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g, where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene and g = wt % vary from 0 to 5 wt.% of rest of the composite sample and its synthesis process, here a, u, v, w, x, y and z are mole % wherein a is = 0 and = 10, u is = 10 and < 50, v is = 02 and = 20, w is = 02 and = 10, and x, y, z = 02 and = 10. [061] Electrochemical Results [062] For sodium storage properties assessment, the composite electrode is made-up of synthesized cathode material, binder and activated carbon in mass ratio of 80:10:10. A thick ink was made using the solvent i.e., 1-methyl 2-pyrro-lidone (NMP, Sigma Aldrich, 98%) and then it was coated onto a current collector (thickness ~ 10-15 µm) before allowing it to get dried at 80 °C in air to evaporate the used solvent. The material coated substrate was then pressed between twin roller and cut in to discs of the diameter of 16 mm diameter followed by de-moisturizing at 70 °C before transferring to an Ar-filled glove box (M-Braun, Germany). [063] For making a Sodium ion (Na-ion) battery coin cell, standard stainless-steel cups and lids fitted with a plastic O-ring were used for the casing. Coin cells (CR2016; 20 mm diameter and 1.6 mm thick) comprised composite electrodes, Na metal as counter electrode, glass filter fiber as the separator and 1 M NaClO4, dissolved in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 by volume) as the Na-ion conducting electrolyte. The electrode was placed at the center of the cup which forms the positive terminal of the cell and wetted with a few drops of the electrolyte. This was covered with the separator that is permeable to the Na-ions but impermeable to particles of the composite electrode and electrons. Circular Na-metal disc of the size ~16 mm diameter was placed centrally on the separator. Then, a steel spring was placed on Na-metal disc and formed the negative terminal of the cell. Finally, hermetic sealing was done with a mechanical press. The weight of active material in the working electrode was kept in the range of 5.0-8.0 mg. [064] Electrochemical characterization (Sodium ion battery): [065] Galvanostatic charge-discharge cycling (GCD) study was performed at room temperature by battery analyzer (Neware). The obtained material can deliver high capacity and stability vs Sodium metal (Na/Na+) in the voltage range of 2.5 V - 4.2V. Thus, the invention could lead to the synthesis of novel, high performance cathode material for Sodium ion batteries (SIBs). [066] The invention will be more fully understood from the following examples. These examples are to be constructed as illustrative of the invention and not limitative thereof: [067] Example 1 Sol gel synthesis of Na3V2-xAlx(PO4)3@C, here x = 10 and = 50 [068] Synthesis Method Na3V1.85Al0.15(PO4)3@C; [069] V2O5 (1.85 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.6188 gm of Al(NO3)3·9H2O were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 hours and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. XRD pattern of Na3V2-xAlx(PO4)3@C, here x = 0.1 and = 0.5 is shown in Figure 1. Sodium storage properties: [070] To investigate the electrochemical behavior of the developed materials, galvanostatic cycling tests were performed in sodium metal cells. Figure 2 shows the electrochemical cycling performance of our novel customized cathode electrode material. In terms of sodium-ion storage performance at 0.1 C, Na3V2-xAlx(PO4)3@C delivered a reversible capacity of around 100 mAh g-1. [071] The data shown in Figure 2 is derived from the constant current cycling data for the cathode material (Na3V2-xAlx(PO4)3@C) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mA g-1 between voltage limits of 2.5 and 4.0 V. Figure 2 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good capacity retention with very low level of voltage hysteresis in case of Na3V1.8Al0.2(PO4)3@C, indicating the relatively high kinetic reversibility of the Na-ion extraction-insertion reactions in this cathode material (Table 1). [072] Example 2 Sol gel synthesis of Na3V2-x-yAlxMny(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20 [073] Synthesis Method Na3V1.75Al0.2Mn0.05(PO4)3@C; V2O5 (1.75 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O and 0.1348 gm of Mn(CH3COO)2.4H2O were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 mins. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 ºC until gel is formed. The material is dried at 90 ºC in an oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 h in Ar/H2 environment. [074] The data shown in Figure 4 derived from the constant current cycling data for the cathode material (Na3V2-x-yAlxMny(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.5 and 4.0 V and/or 2.0 – 4.3 V. Figure 4 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. This data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-x-yAlxMny(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20, justifying the synergetic effect of co-doping of Al and Mn during the Na-ion extraction-insertion reactions in this cathode material. [075] Example 3 Sol gel synthesis of Na3V2-x-y-zAlxMnyMgz(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20, z is = 0 and = 15. [076] Synthesis method; Na3V1.58Al0.2Mn0.12Mg0.1(PO4)3@C. At first V2O5 (1.58 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, 0.282 gm of Mg(CH3COO)2.6H2O were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 hours and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. [077] The data shown in Figure 6 derived from the constant current cycling data for the cathode material (Na3V2-x-y-zAlxMnyMgz(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20, z is = 0 and = 15) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0 – 4.3 V. Figure 6 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-x-y-zAlxMnyMgz(PO4)3@C, here x is = 10 and = 50, y is = 0 and = 20, z is = 0 and = 15, justifying the synergetic effect of Al, Mn and Mg co-doping during the Na-ion extraction-insertion reactions in this cathode material. [078] Example 4 Sol gel synthesis of Na3V2-x-yAlxMnyTiz(PO4)3@C, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15 [079] Synthesis Method; Na3V1.63Al0.2Mn0.12Ti0.05(PO4)3@C V2O5 (1.63 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, and 0.1871 gm Ti (OC4H9)4 of were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. [080] The data shown in Figure 8 derived from the constant current cycling data for the cathode material (Na3V2-x-yAlxMnyTiz(PO4)3@C, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0 – 4.3 V. Figure 8 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. This data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-x-yAlxMnyTiz(PO4)3@C, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15, justifying the synergetic effect of co-doping of Al, Mn and Ti during the Na-ion extraction-insertion reactions in this cathode material. [081] Example 5 Sol gel synthesis of NaV2-x-yAlxMnyTiz(PO4)3@C (MWCNT)a, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15, and a varies from 0 to 5 wt.% [082] Synthesis Method; Na3V1.58Al0.2Mn0.12Ti0.1(PO4)3@C (MWCNT) [Sample No. 36] [083] First different wt.% of MWCNTs, preferably 1 wt.%, is dispersed via sonication for 2h in a solution containing different, preferable equal (100 mL each), concentrations of NMP and DMF to form solution “A”. Separately V2O5 (1.58 gm), oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that solution “A” is mixed into the above clear blue solution followed by the addition of 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, and 0.3742 gm Ti (OC4H9)4 with stirring 20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 hours and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. [084] The data shown in Figure 10 derived from the constant current cycling data for the cathode material (Na3V2-x-yAlxMnyTiz(PO4)3@C (MWCNT)a, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15, and a varies from 0 to 5 wt%) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0 – 4.3 V. Figure 10 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-x-yAlxMnyTiz(PO4)3@C (MWCNT)a, here x = 10 and = 50, y = 0 and = 20, z = 0 and = 15, and “a” varies from 0 to 5 wt%, justifying the synergetic effect of MWCNT on co-doping of Al, Mn and Ti during the Na-ion extraction-insertion reactions in this cathode material [085] Example 6 Na3V2-w-x-y-zAlwMnxTiyMgz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15. [086] Synthesis Method; Na3V1.53Al0.2Mn0.12Ti0.1Mg0.05(PO4)3@C [Sample No. 30] [087] First V2O5 (1.53 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 mins at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, 0.3742 gm Ti (OC4H9)4, and 0.1410 gm of Mg(NO3)3·6H2O were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. Here concentration of Mg is varied from 0 to 15 % for each fixed value of Ti from 0 to 15 %. [088] The data shown in Figure 12 derived from the constant current cycling data for the cathode material (Na3V2-w-x-y-zAlwMnxTiyMgz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0 – 4.3 V. Figure 12 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. This data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-w-x-y-zAlwMnxTiyMgz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15, justifying the synergetic effect co-doping of Al, Mn, Mg and Ti during the Na-ion extraction-insertion reactions in this cathode material. [089] Example 7 Na3V2-w-x-y-zAlwMnxMgyTiz(PO4)3@C, here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15. [090] Synthesis Method; Na3V1.53Al0.2Mn0.12Mg0.1Ti0.05(PO4)3@C [Sample No. 32] [091] First V2O5 (1.53 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, 0.282 gm of Mg(NO3)3·6H2O, and 0.1871 gm of Ti (OC4H9)4 were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. Here concentration of Ti is varied from 0 to 15 % for each fixed value of Mg from 0 to 15 %. [092] The data shown in Figure 14 derived from the constant current cycling data for the cathode material (Na3V2-w-x-y-zAlwMnxMgyTiz(PO4)3@C, Here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0-4.3 V. Figure 14 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-w-x-y-zAlwMnxMgyTiz(PO4)3@C, Here w = 10 and = 50, x = 0 and = 20, y = 0 and = 15 and z = 0 and = 15, justifying the synergetic effect co-doping of Al, Mn, Mg and Ti during the Na-ion extraction-insertion reactions in this cathode material [093] Example 8 Na3V2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15 [094] Synthesis Method; Na3V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 @C [Sample No. 49] [095] First V2O5 (1.5 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, 0.3742 gm of Ti (OC4H9)4, 0.1410 gm of Mg(NO3)3·6H2O, and 0.09592 gm of Ni(NO3)2.6H2O were added in the above solution and stirrer for 15-20 min more. Later 5.146 gm of NaH2PO4 and 3.962 gm of polyvinyl pyrrolidone (PVP) were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 ºC until gel is formed. The material is dried at 90 ºC in an oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. [096] The data shown in Figure 16 derived from the constant current cycling data for the cathode material Na3V2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C , Here v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15 in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0-4.3 V. Figure 16 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3V2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C , Here v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15, justifying the effect of carbon source on the energy storage performance of Al, Mn, Mg and Ti co-doping during the Na-ion extraction-insertion reactions in this cathode material. [097] Example 9 Na3-aLiaV2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here a = 0 and = 10, v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15 [098] Synthesis Method; Na2.93 Li0.07V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 @C [Sample No. 50] [099] First V2O5 (1.5 gm), Oxalic acid (4.16 gm), were dissolved in 50 mL D.I water and stirrer for 45 minutes at 90 ºC to get clear blue solution. After that 0.825 gm of Al(NO3)3·9H2O, 0.3234 gm of Mn(CH3COO)2.4H2O, 0.3742 gm of Ti (OC4H9)4, 0.1410 gm of Mg(NO3)3·6H2O, and 0.09592 gm of Ni(NO3)2.6H2O were added in the above solution and stirrer for 15-20 min more. Later 5.0266 gm of NaH2PO4 , 0.0786 gm of LiCH3COO.2H2O, and 3.962 gm of glucose were added in the above solution and vigorously stirred for next 20 minutes. After that 100 mL DMF was added into the above solution drop by drop with continuous stirring at 90 C until gel is formed. The material is dried at 90 ºC in oven for 12 h and grinded. The grinded material is preheated at 350 ºC for 5 h and then again grinded and heated at 850 ºC for 7-8 hour in Ar/H2 environment. [100] The data shown in Figure 18 derived from the constant current cycling data for the cathode material (Na3-aLiaV2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here a = 0 and = 10, v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15) in a Na-ion cell. The constant current data were collected at an approximate current density of 10 mAg-1 between voltage limits of 2.0 and 4.2 V and/or 2.0-4.3 V. Figure 18 shows the cell voltage profile (V) versus specific capacity (mAhg-1) for the initial cycles. These data demonstrate a good initial capacity with very low level of voltage hysteresis in case of Na3-aLiaV2-v-w-x-y-zAlvMnwTixMgyNiz(PO4)3@C, here a = 0 and = 10, v = 10 and = 50, w = 0 and = 20, x = 0 and = 15, y = 0 and = 15, and z = 0 and = 15, justifying the effect of co-doping of Li, Al, Mn, Mg, Ni and Ti during the Na-ion extraction-insertion reactions in this cathode material. Table 1: A summary of doped sodium vanadium phosphate battery test results are given below in detail: MATERIAL Cell ID Electrode Composition 1ST Charge (mAhg-1) 1ST Discharge (mAhg-1) 25TH Charge (mAhg-1) 25TH Discharge (mAhg-1) Example 1 Na3V1.80Al0.2(PO4)3 A 80:10:10 109 98 97 92 Na3V1.80Al0.2(PO4)3 B 80:10:10 127 99 102 92 Na3V1.80Al0.2(PO4)3 C 80:10:10 117 88 94 82 Na3V1.80Al0.2(PO4)3 D 80:10:10 104 82 88 74 Example 2 Na3V1.75Al0.2Mn0.07(PO4)3 E 80:10:10 143 114 107 105 Na3V1.75Al0.2Mn0.12(PO4)3 F 80:10:10 144 110 103 101 Na3V1.75Al0.2Mn0.15(PO4)3 G 80:10:10 150 114 108 101 Na3V1.75Al0.2Mn0.05(PO4)3 H 80:10:10 159 108 101 99 Example 3 Na3V1.63Al0.2Mn0.12Ti0.02(PO4)3 I 80:10:10 124 106 112 99 Na3V1.63Al0.2Mn0.12Ti0.05(PO4)3 J 80:10:10 125 108 104 104 Na3V1.63Al0.2Mn0.12Ti0.1(PO4)3 K 80:10:10 122 105 108 97 Example 4 Na3V1.58Al0.2Mn0.12Ti0.1(PO4)3 @C (MWCNT) L 80:10:10 117 102 95 94 Na3V1.58Al0.2Mn0.12Ti0.1(PO4)3 @C (MWCNT) M 80:10:10 115 98 100 89 Na3V1.58Al0.2Mn0.12Ti0.1(PO4)3 @C (MWCNT) N 80:10:10 108 87 82 81 Example 5 Na3V1.58Al0.2Mn0.12Mg0.02(PO4)3 O 80:10:10 138 110 105 104 Na3V1.58Al0.2Mn0.12Mg0.05(PO4)3 P 80:10:10 129 106 110 97 Na3V1.58Al0.2Mn0.12Mg0.1(PO4)3 Q 80:10:10 140 121 124 108 Example 6 Na3V1.58Al0.2Mn0.12Ti0.1Mg0.02(PO4)3 R 80:10:10 133 112 116 99 Na3V1.58Al0.2Mn0.12Ti0.1Mg0.05(PO4)3 S 80:10:10 136 108 114 97 Na3V1.58Al0.2Mn0.12Ti0.1Mg0.1(PO4)3 T 80:10:10 128 108 112 96 Example 7 Na3V1.58Al0.2Mn0.12Mg0.1Ti0.02(PO4)3 U 80:10:10 134 111 105 99 Na3V1.58Al0.2Mn0.12Mg0.1Ti0.05(PO4)3 V 80:10:10 137 109 113 97 Na3V1.58Al0.2Mn0.12Mg0.1Ti0.1(PO4)3 W 80:10:10 128 108 112 96 Example 8 Na3V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 80:10:10 109 92 Example 9 Na2.93Li0.07V1.5Al0.2Mn0.12Ti0.1Mg0.05Ni0.03(PO4)3 80:10:10 104 96 [101] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention. ,CLAIMS:WE CLAIM: 1. A high performance and stable cathode material for Sodium ion batteries comprises composite material NaaLbM1cM2dM3eM4f(AB4)3@C(T)g characterized in that Na is 1 < a = 3; L is Li or other alkali metal, and 0 = b < 0.1; M1 is Vanadium, and 1 = c < 2; M2 is Aluminium, and 0.10 = d < 0.50; M3 is Manganese, and 0.02 < e = 0.20 and M4 is Titanium, iron, nickel and magnesium, or mixture of any two or mixture of any three or mixture of all four 0.02 = f = 0.1, and T is the individual or combination of MWCNTs/(rGO/MoS2)/MXene, and 0 = g = 5 (wt% of the rest doped material). 2. The high performance and stable cathode material for Sodium ion batteries, as claimed in claim 1 wherein the electrode active material includes lithium 0 = b < 0.1 in place of sodium. 3. The high performance and stable cathode material for Sodium ion batteries, as claimed in claim 1 wherein the electrode active material includes vanadium in the range varying from 1 = c < 2 and aluminium in the range of 0.10 = d < 0.50. 4. High performance and stable cathode material for Sodium ion batteries, as claimed in claim 1 wherein the electrode active material includes manganese in the range of 0.02 < e = 0.20 and any one, two, three, or all from titanium, iron, nickel and magnesium in the range of 0.02 to 0.1, more precisely 0.02 = f = 0.1. 5. The high performance and stable cathode material for Sodium ion batteries, as claimed in claim 1 wherein the electrode active material includes AB4 wherein A is from the non-transition metal elements phosphorous, arsenic and antimony and B is from the non-transition elements oxygen, Sulphur and selenium. 6. The electrode active material of claim 1 comprises a solid solution of formula NaaLbM1cM2dM3eM4f(AB4)3 wherein, M1 is Vanadium, M2 is Aluminium, M3 is Manganese, M4 = Titanium, iron, nickel and magnesium, or mixture of any two or mixture of any three or mixture of all four with the doped limit of; 1 ? a = 3, 0 = b ? 0.1, 1 = c ? 2, 0.10 = d < 0.50, 0.02 < e = 0.20, 0.02 = f = 0.1. 7. The high performance and stable cathode material for Sodium ion batteries, as claimed in claim 6 wherein the final doping composition of the said electrode active material is chosen from the composition of NaaLbM1cM2dM3eM4f(AB4)3. 8. The high performance and stable cathode material for Sodium ion batteries, as claimed in claim 1 wherein the carbon additive (different wt.%) is chosen any one, any two, or all from glucose, sucrose, and PVP to synthesize NaaLbM1cM2dM3eM4f(AB4)3@CT (=MWCNTs, rGO, MoS2, MXene)g nanocomposite. 9. The method of preparing cathode material for Sodium ion batteries, includes following steps: a) Mixing of homogeneous dispersion of MWCNTs, rGO, MoS2, MXene, or any of two, three, or all four in water, ethanol, NMP, DMF, Isopropyl Alcohol (IPA) or any of two, three, or all five. b) Mixing of vanadium pentoxide (V2O5) and oxalic acid in a certain mole ratio. c) Stirring of the solution at a certain temperature until a clear blue solution is obtained. d) Addition of Aluminium nitrate (Al(NO3)3•9H2O), Manganese acetate (Mn(CH3COO)2.4H2O),or Magnesium acetate (Mg(CH3COO)2.6H2O) or Tetrabutyltitanate (Ti(OBu)4) or Nickel nitrate hexahydrate (Ni(NO3)2.6H2O) or Iron (III) nitrate nonahydrate (Fe(NO3)3.9H2O) or solution of Ti(OC4H9)4 in ethanol in a certain amount to the solution and stirred for some time. e) Addition of Monosodium phosphate (NaH2PO4), lithium acetate de-hydrates in certain mole ratio to the solution and stirred for some time. f) After that certain amount of solution of sucrose, glucose, PVP, PVA or any of two, three, or all four in D.I water is mixed in the above solution (e) and stirred for some time. g) Drop by drop mixing of certain amount of ethanol, Dimethyl formamide (DMF), or any of two, or both in the solution obtained from (f) and stirred. h) Solution obtained from (g) left on stirring at 90 °C until the solution converts to gel. i) The final obtained gel from (h) is dried in an oven . j) After drying, the material was grounded and then pre-heated in a tube furnace at certain temperature under (Ar+H2) gas environment. k) The obtained material was then again grounded and heated in a tube furnace at certain temperature under (Ar+H2) gas environment. The final obtained material is Na3-aLiaV2-u-v-w-x-y-zAluMnvTiwMgxNiyFez(PO4)3@C(T)g, where C is the carbon, T is the individual or combination of MWCNTs/rGO/MoS2/MXene and g = wt % vary from 0 to 5 wt.% of rest the composite sample and its synthesis process, here a, u, v, w, x, y and z are mole % wherein a is = 0 and = 10, u is = 10 and < 50, v is = 02 and = 20, w is = 02 and = 10, and x, y, z = 02 and = 10.