TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method comprises: mixing transition metal compound, phosphate ion-based compound and a lithium-based compound in polyol solvent to prepare a mixed solution; obtaining a resultant metal oxide of formula (LiMx'Fe(1-x')PO4) (II) with nanocrystal structure by reacting the mixed solution in reflux apparatus, where the heat treatment step is not required on the resultant; washing the mixed solution in acetone; filtering the resultant; and drying the resultant. In the method, the mixed solution is heated to the boiling point of polyol solvent after obtaining the resultant in the reflux apparatus, where the boiling point of polyol solvent is 250-350 degrees C. Preferred Components: The metal oxide is (II) or of formula (LiM'y'Fe(1-y')PO4) (III). The transition-metal compound includes iron-based compound, nickel-based compound and/or titanium-based compound. The iron-based compound includes iron(II) acetate, iron(II) nitrate, iron-based compound of formula (FeC2O2), ferrous sulfate, ferrous chloride, ferrous iodide and/or ferrous fluoride. The nickel-based compound includes nickel(II) acetate, nickel(II) nitrate, nickel-based compound of formula (NiC2O2), nickel(II) sulfate, nickel(II) chloride, nickel(II) iodide and/or nickel(II) fluoride. The titanium-based compound includes titanium(II) hydride and/or titanium(IV) isopropoxide. The phosphate ion-based compound includes ammonium dihydrogen phosphate, phosphoric acid, ammonium monohydrogen phosphate and/or ammonium phosphate. The lithium-based compound is includes lithium acetate, lithium hydroxide, lithium nitrate, lithium carbonate, lithium phosphate and/or lithium fluoride.x' = greater than 0 and less than 1;M' = Ni or Ti; andy' = greater than 0 and less than or equal to 0.2, preferably less than or equal to 0.1.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The polyol solvent includes ethylene glycol, diethylene glycol, triethylene glycol and/or tetraethylene glycol (TTEG). EXAMPLE - Iron(II) acetate and nickel(II) acetate in a molar ratio of 0.96:0.04 as transition metal compound were added to TTEG solvent, and then phosphoric acid as phosphate ion-based compound and lithium acetate as lithium-based compound were added in a such a manner that the molar ratio of transition metal compound, phosphoric acid and lithium acetate is 1:1:1 and mixed to prepare a solution. The solution was reacted in a round flask of a reflux apparatus at 328 degrees C as the boiling point of TTEG solvent for 16 hours to obtain electrode material resultant. The mixed solution was then repeatedly washed in acetone, and the resultant was filtered from the mixed solution using a ceramic membrane. The resultant was vacuum dried at 120 degrees C for 24 hours to obtain nickel doped-lithium iron phosphate compound of formula (LiNi(0.04)Fe(0.96)PO4) with olivine structure.