TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The material (M1) further comprises a carbon additive, where the carbon additive is capable of providing the mixed crystal with 1-5 wt.% of carbon. The first crystalline substance and the second crystalline substance have molar ratios of 1 to 0.01-0.05. The first crystalline substance has a combination of lithium, iron and phosphorus sources, where the lithium, iron and phosphorus (Li:Fe:P) sources have molar ratios of 0.95-1.1:1:0.95-1.1. The phosphorus source and the second crystalline substance have molar ratios of 1 to 0.01-0.05, taking only the phosphorus source in the material into consideration. Preferred Components: The carbon additive includes at least one member selected from carbon black or graphite. The first crystalline substance includes at least one member selected from lithium iron phosphate (LiFePO4), lithium manganese phosphate (LiMnPO4), lithium cobalt phosphate (LiCoPO4), Li3Fe2(PO4)3, LiTi2(PO4)3, Li3V2(PO4)3, Li2NaV2(PO4)3, LiTiPO5, LiVMoO6, LiVWO6, LiVP2O7 or LiFeAs2O7. The second crystalline substance includes at least one member selected from Bi4Ti3O12, CuNb2O6, MnTaO4, FeWO4, ZnZrNb2O8, NiNb2O6, NiZrNb2O8, FeTiNb2O8, MnTiNb2O8, MgSnNb2O8, ZnTa2O6, Cu0.85Zn0.15Nb2O6, YBa3Ti2O8.5, Zr0.75Ti0.75Sn0.504, hafnium titanate (HfTiO4), magnesium niobate (MgNb2O6). The lithium source is selected from lithium carbonate or lithium hydroxide. The iron source is selected from ferrous carbonate, iron oxide, iron phosphate, iron pyrophosphate or iron nitrate. The phosphate source is selected from ammonium phosphate, ammonium dihydrogen phosphate, ammonium, iron phosphate, phosphoric acid or lithium dihydrogen phosphate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The lithium source is selected from lithium oxalate or lithium acetate; the iron source is selected from ferrous oxalate or iron acetate. The carbon additive includes acetylene black, glucose, sucrose, citric acid, starch or dextrin.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The carbon additive includes polyethylene glycol. EXAMPLE - Manganese carbonate, titanium oxide (TiO2) and niobium oxide (Nb2O5) in a molar ratio of 1:1:1 were ground in a ball mill for 5 hours, followed by heating in a nitrogen atmosphere at 10-500 degrees C and sintering the product for 10 hours. To a mixture of LiFePO4 and the above formed MnTiNb2O8 in a molar ratio of 1:0.04, was added starch as a source of carbon (amount of carbon capable of providing 5 wt.% carbon content in the final product). The mixture was again ground in a ball mill for 10 hours, removed and dried at 80 degrees C. The resulting powder was heated in a nitrogen or argon atmosphere at 10-600 degrees C, and sintered for 20 hours to provide a LiFePO4/MnTiNb2O8/C mixed crystal cathode active material having an electrical conductivity of 0.175 S/cm at 25 degrees C.