TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: In step (c), the pH is adjusted with sodium hydroxide, ammonium hydroxide, ammonium hydrogen carbonate (all preferred), or other base solution to generate the second mixture. In method: the temperatures of 25-100 degrees C, 60-105 degrees C and 250-600 degrees C are a first temperature, second temperature and third temperature, respectively; and the time periods of 2-5 hours, 1-10 hours, 2-12 hours and 2-20 hours are a first period of time, second period of time, third period of time and fourth period of time, respectively. Preferred Components: The lithium source material is lithium formate, lithium oxide, lithium oxalate, lithium carbonate, lithium hydroxide, lithium acetate, lithium fluoride and/or lithium iodide. The molar ratio of LFP precursor is formed with lithium:iron:phosphate (1:1:1). The iron source compound for preparing ferric phosphate precursor includes ferric materials (ferric hydroxide, ferric nitrate, ferric sulfate, ferric chloride) and/or ferrous source material (ferrous hydroxide, ferrous nitrate and/or ferrous sulfate), where an oxidizing agent is used to oxidize ferrous to ferric, and the oxidizing agent is hydrogen peroxide, sodium peroxide and/or sodium chlorate. The iron source compound for forming ferrous phosphate and ferrous ammonium phosphate precursor is ferrous source material including ferrous hydroxide, ferrous nitrate and/or ferrous sulfate. The phosphate source compound is phosphoric acid, phosphorus pentoxide, ammonium phosphate, diammonium phosphate, ammonium phosphate, monosodium phosphate, disodium phosphate and/or trisodium orthophosphate. The pre-determined molar ratio of iron/phosphate is 1 for ferric phosphate and ferrous ammonium phosphate, and 1.5 for ferrous phosphate. The FP1 and FP2 comprises a micron-size composite that is packed with many submicron nanometer size iron phosphate particles and have a tap density of 0.5-3 g/cm3, where the micron-size is 1-100 mu m and the submicron nanometer-size is 100-800 nm. The inert atmosphere is an essentially non-oxidizing atmosphere achieved through the use of vacuum, inert gases (argon and nitrogen) and/or reduction atmosphere including an argon and hydrogen gas mixture. The nanometer-size active material LFP has a size of 10-300 nm and a tap density of 0.5-3 g/cm3. The LFP1 and LFP2, and active material LFP comprise the micron-size composite. The submicron nanometer-size particle is packed with well dispersed and uniform nanometer particles. The lithium iron phosphate is well dispersed and uniform primary particles of 10-300 nm primary nanoparticles, which form 100-800 nm secondly submicron nanoparticles. The secondly submicron nanoparticles forms 1-100 mu m thirdly micron-size particles. The weight ratio of the carbon source material to the iron source material is 1-45 g/molar.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The carbon source is an inorganic carbon-containing material, an organic carbon-containing material, a polymeric carbon-containing material and/or a natural product carbon source. The solvent is water, ethanol, acetone, ethylene glycol, isopropanol, dimethylformamide and/or acetonitrile. EXAMPLE - Ferrous sulfate heptahydrate (139 g) was dissolved in water (500 ml) to prepare solution (S1). Then ammonium dihydrogen phosphate (55.8 g) was dissolved in water (400 ml) to prepare solution (S2). Then solution (S2) was added into solution (S1) with stirring. Then hydrogen peroxide solution (17%) was added to make all ferrous oxidized to ferric, and adjusted pH to 2.5 with continued stirring. The resultant suspension and precipitate were heated at 90 degrees C under stirring for 4 hours. The resultant mixture was then filtered and thoroughly rinsed with water to form phosphate dihydrate phase (FP1). The resultant solid material FP1 was then dried in an oven at 104 degrees C for overnight, and then heated to 500 degrees C for 5 hours to form ferric phosphate anhydrous phase (FP2). Then mole rate of lithium:iron:phosphate (1:1:1) of lithium carbonate and FP2 were mixed with cellulose acetate (15%) in isopropyl (solvent), heated the mixture at 40 degrees C for 4 hours to form a first lithium iron phosphate precursor (LFP1). The LFP1 was then sintered under argon gas at 350 degrees C for 5 hours to form LFP2. Then the LFP2 was sintered under argon gas at 70 degrees C for 12 hours to obtain electrochemically active material lithium iron phosphate.